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authorScott Wood <scottwood@freescale.com>2014-04-10 00:49:54 (GMT)
committerScott Wood <scottwood@freescale.com>2014-04-10 00:49:54 (GMT)
commitb86c95253af2105c9824146c6569a6b0f39ab124 (patch)
tree9100acbdc843b1081b154135000b89ee95cd10d3
parente5feac72dad5475167445de9af564c2d592872bb (diff)
parent07c8b57b111585a617b2b456497fc9b33c00743c (diff)
downloadlinux-fsl-qoriq-b86c95253af2105c9824146c6569a6b0f39ab124.tar.xz
Merge branch 'rtmerge' into sdk-v1.6.x
This merges 3.12.15-rt25. Signed-off-by: Scott Wood <scottwood@freescale.com> Conflicts: drivers/misc/Makefile drivers/net/ethernet/freescale/gianfar.c drivers/net/ethernet/freescale/gianfar_ethtool.c drivers/net/ethernet/freescale/gianfar_sysfs.c
-rw-r--r--Documentation/hwlat_detector.txt64
-rw-r--r--Documentation/sysrq.txt11
-rw-r--r--Documentation/trace/histograms.txt186
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-rw-r--r--drivers/net/ethernet/3com/3c59x.c8
-rw-r--r--drivers/net/ethernet/atheros/atl1c/atl1c_main.c6
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-rw-r--r--drivers/net/ethernet/chelsio/cxgb/sge.c3
-rw-r--r--drivers/net/ethernet/dec/tulip/tulip_core.c1
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diff --git a/Documentation/hwlat_detector.txt b/Documentation/hwlat_detector.txt
new file mode 100644
index 0000000..cb61516
--- /dev/null
+++ b/Documentation/hwlat_detector.txt
@@ -0,0 +1,64 @@
+Introduction:
+-------------
+
+The module hwlat_detector is a special purpose kernel module that is used to
+detect large system latencies induced by the behavior of certain underlying
+hardware or firmware, independent of Linux itself. The code was developed
+originally to detect SMIs (System Management Interrupts) on x86 systems,
+however there is nothing x86 specific about this patchset. It was
+originally written for use by the "RT" patch since the Real Time
+kernel is highly latency sensitive.
+
+SMIs are usually not serviced by the Linux kernel, which typically does not
+even know that they are occuring. SMIs are instead are set up by BIOS code
+and are serviced by BIOS code, usually for "critical" events such as
+management of thermal sensors and fans. Sometimes though, SMIs are used for
+other tasks and those tasks can spend an inordinate amount of time in the
+handler (sometimes measured in milliseconds). Obviously this is a problem if
+you are trying to keep event service latencies down in the microsecond range.
+
+The hardware latency detector works by hogging all of the cpus for configurable
+amounts of time (by calling stop_machine()), polling the CPU Time Stamp Counter
+for some period, then looking for gaps in the TSC data. Any gap indicates a
+time when the polling was interrupted and since the machine is stopped and
+interrupts turned off the only thing that could do that would be an SMI.
+
+Note that the SMI detector should *NEVER* be used in a production environment.
+It is intended to be run manually to determine if the hardware platform has a
+problem with long system firmware service routines.
+
+Usage:
+------
+
+Loading the module hwlat_detector passing the parameter "enabled=1" (or by
+setting the "enable" entry in "hwlat_detector" debugfs toggled on) is the only
+step required to start the hwlat_detector. It is possible to redefine the
+threshold in microseconds (us) above which latency spikes will be taken
+into account (parameter "threshold=").
+
+Example:
+
+ # modprobe hwlat_detector enabled=1 threshold=100
+
+After the module is loaded, it creates a directory named "hwlat_detector" under
+the debugfs mountpoint, "/debug/hwlat_detector" for this text. It is necessary
+to have debugfs mounted, which might be on /sys/debug on your system.
+
+The /debug/hwlat_detector interface contains the following files:
+
+count - number of latency spikes observed since last reset
+enable - a global enable/disable toggle (0/1), resets count
+max - maximum hardware latency actually observed (usecs)
+sample - a pipe from which to read current raw sample data
+ in the format <timestamp> <latency observed usecs>
+ (can be opened O_NONBLOCK for a single sample)
+threshold - minimum latency value to be considered (usecs)
+width - time period to sample with CPUs held (usecs)
+ must be less than the total window size (enforced)
+window - total period of sampling, width being inside (usecs)
+
+By default we will set width to 500,000 and window to 1,000,000, meaning that
+we will sample every 1,000,000 usecs (1s) for 500,000 usecs (0.5s). If we
+observe any latencies that exceed the threshold (initially 100 usecs),
+then we write to a global sample ring buffer of 8K samples, which is
+consumed by reading from the "sample" (pipe) debugfs file interface.
diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt
index 8cb4d78..d458683 100644
--- a/Documentation/sysrq.txt
+++ b/Documentation/sysrq.txt
@@ -57,10 +57,17 @@ On PowerPC - Press 'ALT - Print Screen (or F13) - <command key>,
On other - If you know of the key combos for other architectures, please
let me know so I can add them to this section.
-On all - write a character to /proc/sysrq-trigger. e.g.:
-
+On all - write a character to /proc/sysrq-trigger, e.g.:
echo t > /proc/sysrq-trigger
+On all - Enable network SysRq by writing a cookie to icmp_echo_sysrq, e.g.
+ echo 0x01020304 >/proc/sys/net/ipv4/icmp_echo_sysrq
+ Send an ICMP echo request with this pattern plus the particular
+ SysRq command key. Example:
+ # ping -c1 -s57 -p0102030468
+ will trigger the SysRq-H (help) command.
+
+
* What are the 'command' keys?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
'b' - Will immediately reboot the system without syncing or unmounting
diff --git a/Documentation/trace/histograms.txt b/Documentation/trace/histograms.txt
new file mode 100644
index 0000000..6f2aeab
--- /dev/null
+++ b/Documentation/trace/histograms.txt
@@ -0,0 +1,186 @@
+ Using the Linux Kernel Latency Histograms
+
+
+This document gives a short explanation how to enable, configure and use
+latency histograms. Latency histograms are primarily relevant in the
+context of real-time enabled kernels (CONFIG_PREEMPT/CONFIG_PREEMPT_RT)
+and are used in the quality management of the Linux real-time
+capabilities.
+
+
+* Purpose of latency histograms
+
+A latency histogram continuously accumulates the frequencies of latency
+data. There are two types of histograms
+- potential sources of latencies
+- effective latencies
+
+
+* Potential sources of latencies
+
+Potential sources of latencies are code segments where interrupts,
+preemption or both are disabled (aka critical sections). To create
+histograms of potential sources of latency, the kernel stores the time
+stamp at the start of a critical section, determines the time elapsed
+when the end of the section is reached, and increments the frequency
+counter of that latency value - irrespective of whether any concurrently
+running process is affected by latency or not.
+- Configuration items (in the Kernel hacking/Tracers submenu)
+ CONFIG_INTERRUPT_OFF_LATENCY
+ CONFIG_PREEMPT_OFF_LATENCY
+
+
+* Effective latencies
+
+Effective latencies are actually occuring during wakeup of a process. To
+determine effective latencies, the kernel stores the time stamp when a
+process is scheduled to be woken up, and determines the duration of the
+wakeup time shortly before control is passed over to this process. Note
+that the apparent latency in user space may be somewhat longer, since the
+process may be interrupted after control is passed over to it but before
+the execution in user space takes place. Simply measuring the interval
+between enqueuing and wakeup may also not appropriate in cases when a
+process is scheduled as a result of a timer expiration. The timer may have
+missed its deadline, e.g. due to disabled interrupts, but this latency
+would not be registered. Therefore, the offsets of missed timers are
+recorded in a separate histogram. If both wakeup latency and missed timer
+offsets are configured and enabled, a third histogram may be enabled that
+records the overall latency as a sum of the timer latency, if any, and the
+wakeup latency. This histogram is called "timerandwakeup".
+- Configuration items (in the Kernel hacking/Tracers submenu)
+ CONFIG_WAKEUP_LATENCY
+ CONFIG_MISSED_TIMER_OFSETS
+
+
+* Usage
+
+The interface to the administration of the latency histograms is located
+in the debugfs file system. To mount it, either enter
+
+mount -t sysfs nodev /sys
+mount -t debugfs nodev /sys/kernel/debug
+
+from shell command line level, or add
+
+nodev /sys sysfs defaults 0 0
+nodev /sys/kernel/debug debugfs defaults 0 0
+
+to the file /etc/fstab. All latency histogram related files are then
+available in the directory /sys/kernel/debug/tracing/latency_hist. A
+particular histogram type is enabled by writing non-zero to the related
+variable in the /sys/kernel/debug/tracing/latency_hist/enable directory.
+Select "preemptirqsoff" for the histograms of potential sources of
+latencies and "wakeup" for histograms of effective latencies etc. The
+histogram data - one per CPU - are available in the files
+
+/sys/kernel/debug/tracing/latency_hist/preemptoff/CPUx
+/sys/kernel/debug/tracing/latency_hist/irqsoff/CPUx
+/sys/kernel/debug/tracing/latency_hist/preemptirqsoff/CPUx
+/sys/kernel/debug/tracing/latency_hist/wakeup/CPUx
+/sys/kernel/debug/tracing/latency_hist/wakeup/sharedprio/CPUx
+/sys/kernel/debug/tracing/latency_hist/missed_timer_offsets/CPUx
+/sys/kernel/debug/tracing/latency_hist/timerandwakeup/CPUx
+
+The histograms are reset by writing non-zero to the file "reset" in a
+particular latency directory. To reset all latency data, use
+
+#!/bin/sh
+
+TRACINGDIR=/sys/kernel/debug/tracing
+HISTDIR=$TRACINGDIR/latency_hist
+
+if test -d $HISTDIR
+then
+ cd $HISTDIR
+ for i in `find . | grep /reset$`
+ do
+ echo 1 >$i
+ done
+fi
+
+
+* Data format
+
+Latency data are stored with a resolution of one microsecond. The
+maximum latency is 10,240 microseconds. The data are only valid, if the
+overflow register is empty. Every output line contains the latency in
+microseconds in the first row and the number of samples in the second
+row. To display only lines with a positive latency count, use, for
+example,
+
+grep -v " 0$" /sys/kernel/debug/tracing/latency_hist/preemptoff/CPU0
+
+#Minimum latency: 0 microseconds.
+#Average latency: 0 microseconds.
+#Maximum latency: 25 microseconds.
+#Total samples: 3104770694
+#There are 0 samples greater or equal than 10240 microseconds
+#usecs samples
+ 0 2984486876
+ 1 49843506
+ 2 58219047
+ 3 5348126
+ 4 2187960
+ 5 3388262
+ 6 959289
+ 7 208294
+ 8 40420
+ 9 4485
+ 10 14918
+ 11 18340
+ 12 25052
+ 13 19455
+ 14 5602
+ 15 969
+ 16 47
+ 17 18
+ 18 14
+ 19 1
+ 20 3
+ 21 2
+ 22 5
+ 23 2
+ 25 1
+
+
+* Wakeup latency of a selected process
+
+To only collect wakeup latency data of a particular process, write the
+PID of the requested process to
+
+/sys/kernel/debug/tracing/latency_hist/wakeup/pid
+
+PIDs are not considered, if this variable is set to 0.
+
+
+* Details of the process with the highest wakeup latency so far
+
+Selected data of the process that suffered from the highest wakeup
+latency that occurred in a particular CPU are available in the file
+
+/sys/kernel/debug/tracing/latency_hist/wakeup/max_latency-CPUx.
+
+In addition, other relevant system data at the time when the
+latency occurred are given.
+
+The format of the data is (all in one line):
+<PID> <Priority> <Latency> (<Timeroffset>) <Command> \
+<- <PID> <Priority> <Command> <Timestamp>
+
+The value of <Timeroffset> is only relevant in the combined timer
+and wakeup latency recording. In the wakeup recording, it is
+always 0, in the missed_timer_offsets recording, it is the same
+as <Latency>.
+
+When retrospectively searching for the origin of a latency and
+tracing was not enabled, it may be helpful to know the name and
+some basic data of the task that (finally) was switching to the
+late real-tlme task. In addition to the victim's data, also the
+data of the possible culprit are therefore displayed after the
+"<-" symbol.
+
+Finally, the timestamp of the time when the latency occurred
+in <seconds>.<microseconds> after the most recent system boot
+is provided.
+
+These data are also reset when the wakeup histogram is reset.
diff --git a/arch/Kconfig b/arch/Kconfig
index af2cc6e..77e7e80 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -6,6 +6,7 @@ config OPROFILE
tristate "OProfile system profiling"
depends on PROFILING
depends on HAVE_OPROFILE
+ depends on !PREEMPT_RT_FULL
select RING_BUFFER
select RING_BUFFER_ALLOW_SWAP
help
diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c
index 98838a0..ee01270 100644
--- a/arch/alpha/mm/fault.c
+++ b/arch/alpha/mm/fault.c
@@ -107,7 +107,7 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
/* If we're in an interrupt context, or have no user context,
we must not take the fault. */
- if (!mm || in_atomic())
+ if (!mm || pagefault_disabled())
goto no_context;
#ifdef CONFIG_ALPHA_LARGE_VMALLOC
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 1ad6fb6..2ec9220 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -51,6 +51,7 @@ config ARM
select HAVE_MOD_ARCH_SPECIFIC if ARM_UNWIND
select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
select HAVE_PERF_EVENTS
+ select HAVE_PREEMPT_LAZY
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UID16
diff --git a/arch/arm/include/asm/switch_to.h b/arch/arm/include/asm/switch_to.h
index c99e259..f3e3d80 100644
--- a/arch/arm/include/asm/switch_to.h
+++ b/arch/arm/include/asm/switch_to.h
@@ -3,6 +3,13 @@
#include <linux/thread_info.h>
+#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM
+void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p);
+#else
+static inline void
+switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { }
+#endif
+
/*
* For v7 SMP cores running a preemptible kernel we may be pre-empted
* during a TLB maintenance operation, so execute an inner-shareable dsb
@@ -22,6 +29,7 @@ extern struct task_struct *__switch_to(struct task_struct *, struct thread_info
#define switch_to(prev,next,last) \
do { \
+ switch_kmaps(prev, next); \
last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \
} while (0)
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index df5e13d..33cb511 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -60,6 +60,7 @@ struct arm_restart_block {
struct thread_info {
unsigned long flags; /* low level flags */
int preempt_count; /* 0 => preemptable, <0 => bug */
+ int preempt_lazy_count; /* 0 => preemptable, <0 => bug */
mm_segment_t addr_limit; /* address limit */
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
@@ -159,6 +160,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
#define TIF_SIGPENDING 0
#define TIF_NEED_RESCHED 1
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
+#define TIF_NEED_RESCHED_LAZY 3
#define TIF_SYSCALL_TRACE 8
#define TIF_SYSCALL_AUDIT 9
#define TIF_SYSCALL_TRACEPOINT 10
@@ -171,6 +173,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index ded0417..12e46dd 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -54,6 +54,7 @@ int main(void)
BLANK();
DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
+ DEFINE(TI_PREEMPT_LAZY, offsetof(struct thread_info, preempt_lazy_count));
DEFINE(TI_ADDR_LIMIT, offsetof(struct thread_info, addr_limit));
DEFINE(TI_TASK, offsetof(struct thread_info, task));
DEFINE(TI_EXEC_DOMAIN, offsetof(struct thread_info, exec_domain));
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index ec3e5cf..8c5e809 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -205,11 +205,18 @@ __irq_svc:
#ifdef CONFIG_PREEMPT
get_thread_info tsk
ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
- ldr r0, [tsk, #TI_FLAGS] @ get flags
teq r8, #0 @ if preempt count != 0
+ bne 1f @ return from exeption
+ ldr r0, [tsk, #TI_FLAGS] @ get flags
+ tst r0, #_TIF_NEED_RESCHED @ if NEED_RESCHED is set
+ blne svc_preempt @ preempt!
+
+ ldr r8, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count
+ teq r8, #0 @ if preempt lazy count != 0
movne r0, #0 @ force flags to 0
- tst r0, #_TIF_NEED_RESCHED
+ tst r0, #_TIF_NEED_RESCHED_LAZY
blne svc_preempt
+1:
#endif
svc_exit r5, irq = 1 @ return from exception
@@ -224,6 +231,8 @@ svc_preempt:
1: bl preempt_schedule_irq @ irq en/disable is done inside
ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
tst r0, #_TIF_NEED_RESCHED
+ bne 1b
+ tst r0, #_TIF_NEED_RESCHED_LAZY
moveq pc, r8 @ go again
b 1b
#endif
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 92f7b15..83af229 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -432,6 +432,30 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
}
#ifdef CONFIG_MMU
+/*
+ * CONFIG_SPLIT_PTLOCK_CPUS results in a page->ptl lock. If the lock is not
+ * initialized by pgtable_page_ctor() then a coredump of the vector page will
+ * fail.
+ */
+static int __init vectors_user_mapping_init_page(void)
+{
+ struct page *page;
+ unsigned long addr = 0xffff0000;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pgd = pgd_offset_k(addr);
+ pud = pud_offset(pgd, addr);
+ pmd = pmd_offset(pud, addr);
+ page = pmd_page(*(pmd));
+
+ pgtable_page_ctor(page);
+
+ return 0;
+}
+late_initcall(vectors_user_mapping_init_page);
+
#ifdef CONFIG_KUSER_HELPERS
/*
* The vectors page is always readable from user space for the
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index ab33042..d1b0bfd 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -589,7 +589,8 @@ asmlinkage int
do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
{
do {
- if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+ if (likely(thread_flags & (_TIF_NEED_RESCHED |
+ _TIF_NEED_RESCHED_LAZY))) {
schedule();
} else {
if (unlikely(!user_mode(regs)))
diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
index 00df012..bbafc67 100644
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -87,7 +87,7 @@ extern const struct unwind_idx __start_unwind_idx[];
static const struct unwind_idx *__origin_unwind_idx;
extern const struct unwind_idx __stop_unwind_idx[];
-static DEFINE_SPINLOCK(unwind_lock);
+static DEFINE_RAW_SPINLOCK(unwind_lock);
static LIST_HEAD(unwind_tables);
/* Convert a prel31 symbol to an absolute address */
@@ -195,7 +195,7 @@ static const struct unwind_idx *unwind_find_idx(unsigned long addr)
/* module unwind tables */
struct unwind_table *table;
- spin_lock_irqsave(&unwind_lock, flags);
+ raw_spin_lock_irqsave(&unwind_lock, flags);
list_for_each_entry(table, &unwind_tables, list) {
if (addr >= table->begin_addr &&
addr < table->end_addr) {
@@ -207,7 +207,7 @@ static const struct unwind_idx *unwind_find_idx(unsigned long addr)
break;
}
}
- spin_unlock_irqrestore(&unwind_lock, flags);
+ raw_spin_unlock_irqrestore(&unwind_lock, flags);
}
pr_debug("%s: idx = %p\n", __func__, idx);
@@ -469,9 +469,9 @@ struct unwind_table *unwind_table_add(unsigned long start, unsigned long size,
tab->begin_addr = text_addr;
tab->end_addr = text_addr + text_size;
- spin_lock_irqsave(&unwind_lock, flags);
+ raw_spin_lock_irqsave(&unwind_lock, flags);
list_add_tail(&tab->list, &unwind_tables);
- spin_unlock_irqrestore(&unwind_lock, flags);
+ raw_spin_unlock_irqrestore(&unwind_lock, flags);
return tab;
}
@@ -483,9 +483,9 @@ void unwind_table_del(struct unwind_table *tab)
if (!tab)
return;
- spin_lock_irqsave(&unwind_lock, flags);
+ raw_spin_lock_irqsave(&unwind_lock, flags);
list_del(&tab->list);
- spin_unlock_irqrestore(&unwind_lock, flags);
+ raw_spin_unlock_irqrestore(&unwind_lock, flags);
kfree(tab);
}
diff --git a/arch/arm/mach-at91/at91rm9200_time.c b/arch/arm/mach-at91/at91rm9200_time.c
index f607deb..35f7b26 100644
--- a/arch/arm/mach-at91/at91rm9200_time.c
+++ b/arch/arm/mach-at91/at91rm9200_time.c
@@ -134,6 +134,7 @@ clkevt32k_mode(enum clock_event_mode mode, struct clock_event_device *dev)
break;
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
+ remove_irq(NR_IRQS_LEGACY + AT91_ID_SYS, &at91rm9200_timer_irq);
case CLOCK_EVT_MODE_RESUME:
irqmask = 0;
break;
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
index bb39232..1c4c487 100644
--- a/arch/arm/mach-at91/at91sam926x_time.c
+++ b/arch/arm/mach-at91/at91sam926x_time.c
@@ -77,7 +77,7 @@ static struct clocksource pit_clk = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-
+static struct irqaction at91sam926x_pit_irq;
/*
* Clockevent device: interrupts every 1/HZ (== pit_cycles * MCK/16)
*/
@@ -86,6 +86,8 @@ pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
{
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
+ /* Set up irq handler */
+ setup_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
/* update clocksource counter */
pit_cnt += pit_cycle * PIT_PICNT(pit_read(AT91_PIT_PIVR));
pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN
@@ -98,6 +100,7 @@ pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
case CLOCK_EVT_MODE_UNUSED:
/* disable irq, leaving the clocksource active */
pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
+ remove_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
break;
case CLOCK_EVT_MODE_RESUME:
break;
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index 58b43e6..f56f767 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -73,7 +73,7 @@ static void __iomem *scu_base_addr(void)
return (void __iomem *)(S5P_VA_SCU);
}
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static void exynos_secondary_init(unsigned int cpu)
{
@@ -86,8 +86,8 @@ static void exynos_secondary_init(unsigned int cpu)
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -99,7 +99,7 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
* Set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -128,7 +128,7 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
if (timeout == 0) {
printk(KERN_ERR "cpu1 power enable failed");
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return -ETIMEDOUT;
}
}
@@ -167,7 +167,7 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-msm/platsmp.c b/arch/arm/mach-msm/platsmp.c
index 3f06edc..fc09a04 100644
--- a/arch/arm/mach-msm/platsmp.c
+++ b/arch/arm/mach-msm/platsmp.c
@@ -30,7 +30,7 @@
extern void msm_secondary_startup(void);
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static inline int get_core_count(void)
{
@@ -50,8 +50,8 @@ static void msm_secondary_init(unsigned int cpu)
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static void prepare_cold_cpu(unsigned int cpu)
@@ -88,7 +88,7 @@ static int msm_boot_secondary(unsigned int cpu, struct task_struct *idle)
* set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -122,7 +122,7 @@ static int msm_boot_secondary(unsigned int cpu, struct task_struct *idle)
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
index 8912110..5969da3 100644
--- a/arch/arm/mach-omap2/omap-smp.c
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -44,7 +44,7 @@ u16 pm44xx_errata;
/* SCU base address */
static void __iomem *scu_base;
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
void __iomem *omap4_get_scu_base(void)
{
@@ -68,8 +68,8 @@ static void omap4_secondary_init(unsigned int cpu)
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -83,7 +83,7 @@ static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
* Set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* Update the AuxCoreBoot0 with boot state for secondary core.
@@ -160,7 +160,7 @@ static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
* Now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return 0;
}
diff --git a/arch/arm/mach-prima2/platsmp.c b/arch/arm/mach-prima2/platsmp.c
index 3dbcb1a..42837dc4 100644
--- a/arch/arm/mach-prima2/platsmp.c
+++ b/arch/arm/mach-prima2/platsmp.c
@@ -23,7 +23,7 @@
static void __iomem *scu_base;
static void __iomem *rsc_base;
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static struct map_desc scu_io_desc __initdata = {
.length = SZ_4K,
@@ -56,8 +56,8 @@ static void sirfsoc_secondary_init(unsigned int cpu)
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static struct of_device_id rsc_ids[] = {
@@ -95,7 +95,7 @@ static int sirfsoc_boot_secondary(unsigned int cpu, struct task_struct *idle)
/* make sure write buffer is drained */
mb();
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -128,7 +128,7 @@ static int sirfsoc_boot_secondary(unsigned int cpu, struct task_struct *idle)
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-spear/platsmp.c b/arch/arm/mach-spear/platsmp.c
index 5c4a198..33dc270 100644
--- a/arch/arm/mach-spear/platsmp.c
+++ b/arch/arm/mach-spear/platsmp.c
@@ -20,7 +20,7 @@
#include <mach/spear.h>
#include "generic.h"
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static void __iomem *scu_base = IOMEM(VA_SCU_BASE);
@@ -36,8 +36,8 @@ static void spear13xx_secondary_init(unsigned int cpu)
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -48,7 +48,7 @@ static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle)
* set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -75,7 +75,7 @@ static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle)
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-sti/platsmp.c b/arch/arm/mach-sti/platsmp.c
index dce50d9..c05b764 100644
--- a/arch/arm/mach-sti/platsmp.c
+++ b/arch/arm/mach-sti/platsmp.c
@@ -35,7 +35,7 @@ static void write_pen_release(int val)
outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
}
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
void sti_secondary_init(unsigned int cpu)
{
@@ -50,8 +50,8 @@ void sti_secondary_init(unsigned int cpu)
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
int sti_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -62,7 +62,7 @@ int sti_boot_secondary(unsigned int cpu, struct task_struct *idle)
* set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -93,7 +93,7 @@ int sti_boot_secondary(unsigned int cpu, struct task_struct *idle)
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c
index 1f296e7..eeb5916 100644
--- a/arch/arm/mach-ux500/platsmp.c
+++ b/arch/arm/mach-ux500/platsmp.c
@@ -52,7 +52,7 @@ static void __iomem *scu_base_addr(void)
return NULL;
}
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static void ux500_secondary_init(unsigned int cpu)
{
@@ -65,8 +65,8 @@ static void ux500_secondary_init(unsigned int cpu)
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -77,7 +77,7 @@ static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
* set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -98,7 +98,7 @@ static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index eb8830a..b40d4ba 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -277,7 +277,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if (user_mode(regs))
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index 21b9e1b..bd41dd8 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -38,6 +38,7 @@ EXPORT_SYMBOL(kunmap);
void *kmap_atomic(struct page *page)
{
+ pte_t pte = mk_pte(page, kmap_prot);
unsigned int idx;
unsigned long vaddr;
void *kmap;
@@ -76,7 +77,10 @@ void *kmap_atomic(struct page *page)
* in place, so the contained TLB flush ensures the TLB is updated
* with the new mapping.
*/
- set_top_pte(vaddr, mk_pte(page, kmap_prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = pte;
+#endif
+ set_top_pte(vaddr, pte);
return (void *)vaddr;
}
@@ -93,12 +97,15 @@ void __kunmap_atomic(void *kvaddr)
if (cache_is_vivt())
__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = __pte(0);
+#endif
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
- set_top_pte(vaddr, __pte(0));
#else
(void) idx; /* to kill a warning */
#endif
+ set_top_pte(vaddr, __pte(0));
kmap_atomic_idx_pop();
} else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
/* this address was obtained through kmap_high_get() */
@@ -110,6 +117,7 @@ EXPORT_SYMBOL(__kunmap_atomic);
void *kmap_atomic_pfn(unsigned long pfn)
{
+ pte_t pte = pfn_pte(pfn, kmap_prot);
unsigned long vaddr;
int idx, type;
@@ -121,7 +129,10 @@ void *kmap_atomic_pfn(unsigned long pfn)
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(get_top_pte(vaddr)));
#endif
- set_top_pte(vaddr, pfn_pte(pfn, kmap_prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = pte;
+#endif
+ set_top_pte(vaddr, pte);
return (void *)vaddr;
}
@@ -135,3 +146,29 @@ struct page *kmap_atomic_to_page(const void *ptr)
return pte_page(get_top_pte(vaddr));
}
+
+#if defined CONFIG_PREEMPT_RT_FULL
+void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p)
+{
+ int i;
+
+ /*
+ * Clear @prev's kmap_atomic mappings
+ */
+ for (i = 0; i < prev_p->kmap_idx; i++) {
+ int idx = i + KM_TYPE_NR * smp_processor_id();
+
+ set_top_pte(__fix_to_virt(FIX_KMAP_BEGIN + idx), __pte(0));
+ }
+ /*
+ * Restore @next_p's kmap_atomic mappings
+ */
+ for (i = 0; i < next_p->kmap_idx; i++) {
+ int idx = i + KM_TYPE_NR * smp_processor_id();
+
+ if (!pte_none(next_p->kmap_pte[i]))
+ set_top_pte(__fix_to_virt(FIX_KMAP_BEGIN + idx),
+ next_p->kmap_pte[i]);
+ }
+}
+#endif
diff --git a/arch/arm/plat-versatile/platsmp.c b/arch/arm/plat-versatile/platsmp.c
index 39895d8..b2e0858 100644
--- a/arch/arm/plat-versatile/platsmp.c
+++ b/arch/arm/plat-versatile/platsmp.c
@@ -31,7 +31,7 @@ static void write_pen_release(int val)
outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
}
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
void versatile_secondary_init(unsigned int cpu)
{
@@ -44,8 +44,8 @@ void versatile_secondary_init(unsigned int cpu)
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -56,7 +56,7 @@ int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
* Set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* This is really belt and braces; we hold unintended secondary
@@ -86,7 +86,7 @@ int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/avr32/mm/fault.c b/arch/avr32/mm/fault.c
index 0eca933..25920d2 100644
--- a/arch/avr32/mm/fault.c
+++ b/arch/avr32/mm/fault.c
@@ -81,7 +81,7 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
* If we're in an interrupt or have no user context, we must
* not take the fault...
*/
- if (in_atomic() || !mm || regs->sr & SYSREG_BIT(GM))
+ if (!mm || regs->sr & SYSREG_BIT(GM) || pagefault_disabled())
goto no_context;
local_irq_enable();
diff --git a/arch/cris/mm/fault.c b/arch/cris/mm/fault.c
index 1790f22..281e859 100644
--- a/arch/cris/mm/fault.c
+++ b/arch/cris/mm/fault.c
@@ -113,7 +113,7 @@ do_page_fault(unsigned long address, struct pt_regs *regs,
* user context, we must not take the fault.
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if (user_mode(regs))
diff --git a/arch/frv/mm/fault.c b/arch/frv/mm/fault.c
index 9a66372..8d9fc16 100644
--- a/arch/frv/mm/fault.c
+++ b/arch/frv/mm/fault.c
@@ -78,7 +78,7 @@ asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if (user_mode(__frame))
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index 7225dad..164db10 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -96,7 +96,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
/*
* If we're in an interrupt or have no user context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
#ifdef CONFIG_VIRTUAL_MEM_MAP
diff --git a/arch/m32r/mm/fault.c b/arch/m32r/mm/fault.c
index e9c6a80..ccb6797 100644
--- a/arch/m32r/mm/fault.c
+++ b/arch/m32r/mm/fault.c
@@ -114,7 +114,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code,
* If we're in an interrupt or have no user context or are running in an
* atomic region then we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto bad_area_nosemaphore;
if (error_code & ACE_USERMODE)
diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c
index eb1d61f..76bee37 100644
--- a/arch/m68k/mm/fault.c
+++ b/arch/m68k/mm/fault.c
@@ -85,7 +85,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if (user_mode(regs))
diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c
index fa4cf52..13d6b07 100644
--- a/arch/microblaze/mm/fault.c
+++ b/arch/microblaze/mm/fault.c
@@ -107,7 +107,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
if ((error_code & 0x13) == 0x13 || (error_code & 0x11) == 0x11)
is_write = 0;
- if (unlikely(in_atomic() || !mm)) {
+ if (unlikely(!mm || pagefault_disabled())) {
if (kernel_mode(regs))
goto bad_area_nosemaphore;
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index f75ab4a..f3981c2 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2078,7 +2078,7 @@ config CPU_R4400_WORKAROUNDS
#
config HIGHMEM
bool "High Memory Support"
- depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM
+ depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM && !PREEMPT_RT_FULL
config CPU_SUPPORTS_HIGHMEM
bool
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 2f285ab..a4ae7ad 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -573,6 +573,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
__u32 thread_info_flags)
{
local_irq_enable();
+ preempt_check_resched();
user_exit();
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index becc42b..6a492c0 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -89,7 +89,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto bad_area_nosemaphore;
if (user_mode(regs))
diff --git a/arch/mn10300/mm/fault.c b/arch/mn10300/mm/fault.c
index 3516cbd..8bd4425 100644
--- a/arch/mn10300/mm/fault.c
+++ b/arch/mn10300/mm/fault.c
@@ -168,7 +168,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long fault_code,
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR)
diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
index 0293588..f16f57b 100644
--- a/arch/parisc/mm/fault.c
+++ b/arch/parisc/mm/fault.c
@@ -177,7 +177,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
int fault;
unsigned int flags;
- if (in_atomic())
+ if (pagefault_disabled())
goto no_context;
tsk = current;
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1532ca9..95c2bf0 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -60,10 +60,11 @@ config LOCKDEP_SUPPORT
config RWSEM_GENERIC_SPINLOCK
bool
+ default y if PREEMPT_RT_FULL
config RWSEM_XCHGADD_ALGORITHM
bool
- default y
+ default y if !PREEMPT_RT_FULL
config GENERIC_LOCKBREAK
bool
@@ -131,6 +132,7 @@ config PPC
select GENERIC_CLOCKEVENTS
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
+ select HAVE_PREEMPT_LAZY
select HAVE_MOD_ARCH_SPECIFIC
select MODULES_USE_ELF_RELA
select CLONE_BACKWARDS
@@ -285,7 +287,7 @@ menu "Kernel options"
config HIGHMEM
bool "High memory support"
- depends on PPC32
+ depends on PPC32 && !PREEMPT_RT_FULL
source kernel/Kconfig.hz
source kernel/Kconfig.preempt
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index ba7b197..f50711f 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -43,6 +43,8 @@ struct thread_info {
int cpu; /* cpu we're on */
int preempt_count; /* 0 => preemptable,
<0 => BUG */
+ int preempt_lazy_count; /* 0 => preemptable,
+ <0 => BUG */
struct restart_block restart_block;
unsigned long local_flags; /* private flags for thread */
@@ -90,8 +92,7 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_SIGPENDING 1 /* signal pending */
#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
-#define TIF_POLLING_NRFLAG 3 /* true if poll_idle() is polling
- TIF_NEED_RESCHED */
+#define TIF_NEED_RESCHED_LAZY 3 /* lazy rescheduling necessary */
#define TIF_32BIT 4 /* 32 bit binary */
#define TIF_PERFMON_WORK 5 /* work for pfm_handle_work() */
#define TIF_PERFMON_CTXSW 6 /* perfmon needs ctxsw calls */
@@ -107,6 +108,8 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_EMULATE_STACK_STORE 16 /* Is an instruction emulation
for stack store? */
#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
+#define TIF_POLLING_NRFLAG 18 /* true if poll_idle() is polling
+ TIF_NEED_RESCHED */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@@ -126,13 +129,16 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_EMULATE_STACK_STORE (1<<TIF_EMULATE_STACK_STORE)
#define _TIF_NOHZ (1<<TIF_NOHZ)
+#define _TIF_NEED_RESCHED_LAZY (1<<TIF_NEED_RESCHED_LAZY)
#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
_TIF_NOHZ)
#define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
- _TIF_NOTIFY_RESUME | _TIF_UPROBE)
+ _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
+ _TIF_NEED_RESCHED_LAZY)
#define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR)
+#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
/* Bits in local_flags */
/* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 1d641d9..53fe65e 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -165,6 +165,7 @@ int main(void)
DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
DEFINE(TI_LOCAL_FLAGS, offsetof(struct thread_info, local_flags));
DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
+ DEFINE(TI_PREEMPT_LAZY, offsetof(struct thread_info, preempt_lazy_count));
DEFINE(TI_TASK, offsetof(struct thread_info, task));
DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 8041d10..59848e5 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -891,7 +891,14 @@ resume_kernel:
cmpwi 0,r0,0 /* if non-zero, just restore regs and return */
bne restore
andi. r8,r8,_TIF_NEED_RESCHED
+ bne+ 1f
+ lwz r0,TI_PREEMPT_LAZY(r9)
+ cmpwi 0,r0,0 /* if non-zero, just restore regs and return */
+ bne restore
+ lwz r0,TI_FLAGS(r9)
+ andi. r0,r0,_TIF_NEED_RESCHED_LAZY
beq+ restore
+1:
lwz r3,_MSR(r1)
andi. r0,r3,MSR_EE /* interrupts off? */
beq restore /* don't schedule if so */
@@ -902,11 +909,11 @@ resume_kernel:
*/
bl trace_hardirqs_off
#endif
-1: bl preempt_schedule_irq
+2: bl preempt_schedule_irq
CURRENT_THREAD_INFO(r9, r1)
lwz r3,TI_FLAGS(r9)
- andi. r0,r3,_TIF_NEED_RESCHED
- bne- 1b
+ andi. r0,r3,_TIF_NEED_RESCHED_MASK
+ bne- 2b
#ifdef CONFIG_TRACE_IRQFLAGS
/* And now, to properly rebalance the above, we tell lockdep they
* are being turned back on, which will happen when we return
@@ -1227,7 +1234,7 @@ global_dbcr0:
#endif /* !(CONFIG_4xx || CONFIG_BOOKE) */
do_work: /* r10 contains MSR_KERNEL here */
- andi. r0,r9,_TIF_NEED_RESCHED
+ andi. r0,r9,_TIF_NEED_RESCHED_MASK
beq do_user_signal
do_resched: /* r10 contains MSR_KERNEL here */
@@ -1248,7 +1255,7 @@ recheck:
MTMSRD(r10) /* disable interrupts */
CURRENT_THREAD_INFO(r9, r1)
lwz r9,TI_FLAGS(r9)
- andi. r0,r9,_TIF_NEED_RESCHED
+ andi. r0,r9,_TIF_NEED_RESCHED_MASK
bne- do_resched
andi. r0,r9,_TIF_USER_WORK_MASK
beq restore_user
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 7be3717..e6bfe8e 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -659,7 +659,7 @@ _GLOBAL(ret_from_except_lite)
#else
beq restore
#endif
-1: andi. r0,r4,_TIF_NEED_RESCHED
+1: andi. r0,r4,_TIF_NEED_RESCHED_MASK
beq 2f
bl .restore_interrupts
SCHEDULE_USER
@@ -709,10 +709,18 @@ resume_kernel:
#ifdef CONFIG_PREEMPT
/* Check if we need to preempt */
+ lwz r8,TI_PREEMPT(r9)
+ cmpwi 0,r8,0 /* if non-zero, just restore regs and return */
+ bne restore
andi. r0,r4,_TIF_NEED_RESCHED
+ bne+ check_count
+
+ andi. r0,r4,_TIF_NEED_RESCHED_LAZY
beq+ restore
+ lwz r8,TI_PREEMPT_LAZY(r9)
+
/* Check that preempt_count() == 0 and interrupts are enabled */
- lwz r8,TI_PREEMPT(r9)
+check_count:
cmpwi cr1,r8,0
ld r0,SOFTE(r1)
cmpdi r0,0
@@ -729,7 +737,7 @@ resume_kernel:
/* Re-test flags and eventually loop */
CURRENT_THREAD_INFO(r9, r1)
ld r4,TI_FLAGS(r9)
- andi. r0,r4,_TIF_NEED_RESCHED
+ andi. r0,r4,_TIF_NEED_RESCHED_MASK
bne 1b
/*
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index c7cb8c2..f3ed55a 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -594,6 +594,7 @@ void irq_ctx_init(void)
}
}
+#ifndef CONFIG_PREEMPT_RT_FULL
static inline void do_softirq_onstack(void)
{
struct thread_info *curtp, *irqtp;
@@ -626,6 +627,7 @@ void do_softirq(void)
local_irq_restore(flags);
}
+#endif
irq_hw_number_t virq_to_hw(unsigned int virq)
{
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index ace3413..84cbc94 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -40,6 +40,7 @@
* We store the saved ksp_limit in the unused part
* of the STACK_FRAME_OVERHEAD
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
_GLOBAL(call_do_softirq)
mflr r0
stw r0,4(r1)
@@ -56,6 +57,7 @@ _GLOBAL(call_do_softirq)
stw r10,THREAD+KSP_LIMIT(r2)
mtlr r0
blr
+#endif
/*
* void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp);
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index e59caf8..f93987e 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -29,6 +29,7 @@
.text
+#ifndef CONFIG_PREEMPT_RT_FULL
_GLOBAL(call_do_softirq)
mflr r0
std r0,16(r1)
@@ -39,6 +40,7 @@ _GLOBAL(call_do_softirq)
ld r0,16(r1)
mtlr r0
blr
+#endif
_GLOBAL(call_do_irq)
mflr r0
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index ea429ff..bc12e6a 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -423,7 +423,7 @@ unsigned long profile_pc(struct pt_regs *regs)
EXPORT_SYMBOL(profile_pc);
#endif
-#ifdef CONFIG_IRQ_WORK
+#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL)
/*
* 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 51ab9e7..45aa26e 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -261,7 +261,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
if (!arch_irq_disabled_regs(regs))
local_irq_enable();
- if (in_atomic() || mm == NULL) {
+ if (in_atomic() || mm == NULL || pagefault_disabled()) {
if (!user_mode(regs)) {
rc = SIGSEGV;
goto bail;
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
index b69221b..2898b73 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
@@ -340,7 +340,7 @@ static int mpc52xx_irqhost_map(struct irq_domain *h, unsigned int virq,
{
int l1irq;
int l2irq;
- struct irq_chip *irqchip;
+ struct irq_chip *uninitialized_var(irqchip);
void *hndlr;
int type;
u32 reg;
@@ -373,9 +373,8 @@ static int mpc52xx_irqhost_map(struct irq_domain *h, unsigned int virq,
case MPC52xx_IRQ_L1_PERP: irqchip = &mpc52xx_periph_irqchip; break;
case MPC52xx_IRQ_L1_SDMA: irqchip = &mpc52xx_sdma_irqchip; break;
case MPC52xx_IRQ_L1_CRIT:
- default:
pr_warn("%s: Critical IRQ #%d is unsupported! Nopping it.\n",
- __func__, l1irq);
+ __func__, l2irq);
irq_set_chip(virq, &no_irq_chip);
return 0;
}
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index fc66792..6b0efce 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -296,7 +296,8 @@ static inline int do_exception(struct pt_regs *regs, int access)
* user context.
*/
fault = VM_FAULT_BADCONTEXT;
- if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm))
+ if (unlikely(!user_space_fault(trans_exc_code) ||
+ !mm || pagefault_disabled()))
goto out;
address = trans_exc_code & __FAIL_ADDR_MASK;
@@ -442,7 +443,8 @@ void __kprobes do_asce_exception(struct pt_regs *regs)
clear_tsk_thread_flag(current, TIF_PER_TRAP);
trans_exc_code = regs->int_parm_long;
- if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm))
+ if (unlikely(!user_space_fault(trans_exc_code) || !mm ||
+ pagefault_disabled()))
goto no_context;
down_read(&mm->mmap_sem);
diff --git a/arch/score/mm/fault.c b/arch/score/mm/fault.c
index 52238983..35d339b 100644
--- a/arch/score/mm/fault.c
+++ b/arch/score/mm/fault.c
@@ -73,7 +73,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto bad_area_nosemaphore;
if (user_mode(regs))
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index 063af10..ae4b141 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -149,6 +149,7 @@ void irq_ctx_exit(int cpu)
hardirq_ctx[cpu] = NULL;
}
+#ifndef CONFIG_PREEMPT_RT_FULL
asmlinkage void do_softirq(void)
{
unsigned long flags;
@@ -191,6 +192,7 @@ asmlinkage void do_softirq(void)
local_irq_restore(flags);
}
+#endif
#else
static inline void handle_one_irq(unsigned int irq)
{
diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c
index 541dc61..6589138 100644
--- a/arch/sh/mm/fault.c
+++ b/arch/sh/mm/fault.c
@@ -438,7 +438,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
* If we're in an interrupt, have no user context or are running
* in an atomic region then we must not take the fault:
*/
- if (unlikely(in_atomic() || !mm)) {
+ if (unlikely(!mm || pagefault_disabled())) {
bad_area_nosemaphore(regs, error_code, address);
return;
}
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 78c4fdb..da51da9 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -26,6 +26,7 @@ config SPARC
select HAVE_DMA_ATTRS
select HAVE_DMA_API_DEBUG
select HAVE_ARCH_JUMP_LABEL
+ select IRQ_FORCED_THREADING
select GENERIC_IRQ_SHOW
select ARCH_WANT_IPC_PARSE_VERSION
select USE_GENERIC_SMP_HELPERS if SMP
@@ -177,12 +178,10 @@ config NR_CPUS
source kernel/Kconfig.hz
config RWSEM_GENERIC_SPINLOCK
- bool
- default y if SPARC32
+ def_bool PREEMPT_RT_FULL
config RWSEM_XCHGADD_ALGORITHM
- bool
- default y if SPARC64
+ def_bool !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT_FULL
config GENERIC_HWEIGHT
bool
@@ -523,6 +522,10 @@ menu "Executable file formats"
source "fs/Kconfig.binfmt"
+config EARLY_PRINTK
+ bool
+ default y
+
config COMPAT
bool
depends on SPARC64
diff --git a/arch/sparc/include/asm/mmu_64.h b/arch/sparc/include/asm/mmu_64.h
index 76092c4..e945ddb 100644
--- a/arch/sparc/include/asm/mmu_64.h
+++ b/arch/sparc/include/asm/mmu_64.h
@@ -90,7 +90,7 @@ struct tsb_config {
#endif
typedef struct {
- spinlock_t lock;
+ raw_spinlock_t lock;
unsigned long sparc64_ctx_val;
unsigned long huge_pte_count;
struct page *pgtable_page;
diff --git a/arch/sparc/include/asm/mmu_context_64.h b/arch/sparc/include/asm/mmu_context_64.h
index 3d528f0..44e393b 100644
--- a/arch/sparc/include/asm/mmu_context_64.h
+++ b/arch/sparc/include/asm/mmu_context_64.h
@@ -13,7 +13,7 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
}
-extern spinlock_t ctx_alloc_lock;
+extern raw_spinlock_t ctx_alloc_lock;
extern unsigned long tlb_context_cache;
extern unsigned long mmu_context_bmap[];
@@ -77,7 +77,7 @@ static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, str
if (unlikely(mm == &init_mm))
return;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
ctx_valid = CTX_VALID(mm->context);
if (!ctx_valid)
get_new_mmu_context(mm);
@@ -125,7 +125,7 @@ static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, str
__flush_tlb_mm(CTX_HWBITS(mm->context),
SECONDARY_CONTEXT);
}
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
#define deactivate_mm(tsk,mm) do { } while (0)
@@ -136,7 +136,7 @@ static inline void activate_mm(struct mm_struct *active_mm, struct mm_struct *mm
unsigned long flags;
int cpu;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
if (!CTX_VALID(mm->context))
get_new_mmu_context(mm);
cpu = smp_processor_id();
@@ -146,7 +146,7 @@ static inline void activate_mm(struct mm_struct *active_mm, struct mm_struct *mm
load_secondary_context(mm);
__flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT);
tsb_context_switch(mm);
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
#endif /* !(__ASSEMBLY__) */
diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c
index d4840ce..d74fa7f 100644
--- a/arch/sparc/kernel/irq_64.c
+++ b/arch/sparc/kernel/irq_64.c
@@ -698,6 +698,7 @@ void __irq_entry handler_irq(int pil, struct pt_regs *regs)
set_irq_regs(old_regs);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
void do_softirq(void)
{
unsigned long flags;
@@ -723,6 +724,7 @@ void do_softirq(void)
local_irq_restore(flags);
}
+#endif
#ifdef CONFIG_HOTPLUG_CPU
void fixup_irqs(void)
diff --git a/arch/sparc/kernel/pcr.c b/arch/sparc/kernel/pcr.c
index 269af58..dbb51a6 100644
--- a/arch/sparc/kernel/pcr.c
+++ b/arch/sparc/kernel/pcr.c
@@ -43,10 +43,12 @@ void __irq_entry deferred_pcr_work_irq(int irq, struct pt_regs *regs)
set_irq_regs(old_regs);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
void arch_irq_work_raise(void)
{
set_softint(1 << PIL_DEFERRED_PCR_WORK);
}
+#endif
const struct pcr_ops *pcr_ops;
EXPORT_SYMBOL_GPL(pcr_ops);
diff --git a/arch/sparc/kernel/setup_32.c b/arch/sparc/kernel/setup_32.c
index 1434526..0884ccd 100644
--- a/arch/sparc/kernel/setup_32.c
+++ b/arch/sparc/kernel/setup_32.c
@@ -309,6 +309,7 @@ void __init setup_arch(char **cmdline_p)
boot_flags_init(*cmdline_p);
+ early_console = &prom_early_console;
register_console(&prom_early_console);
printk("ARCH: ");
diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c
index 3fdb455..4306d44 100644
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -555,6 +555,12 @@ static void __init init_sparc64_elf_hwcap(void)
pause_patch();
}
+static inline void register_prom_console(void)
+{
+ early_console = &prom_early_console;
+ register_console(&prom_early_console);
+}
+
void __init setup_arch(char **cmdline_p)
{
/* Initialize PROM console and command line. */
@@ -566,7 +572,7 @@ void __init setup_arch(char **cmdline_p)
#ifdef CONFIG_EARLYFB
if (btext_find_display())
#endif
- register_console(&prom_early_console);
+ register_prom_console();
if (tlb_type == hypervisor)
printk("ARCH: SUN4V\n");
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index e142545..8c68424 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -976,12 +976,12 @@ void __irq_entry smp_new_mmu_context_version_client(int irq, struct pt_regs *reg
if (unlikely(!mm || (mm == &init_mm)))
return;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
if (unlikely(!CTX_VALID(mm->context)))
get_new_mmu_context(mm);
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
load_secondary_context(mm);
__flush_tlb_mm(CTX_HWBITS(mm->context),
diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c
index 59dbd46..2eaca28 100644
--- a/arch/sparc/mm/fault_32.c
+++ b/arch/sparc/mm/fault_32.c
@@ -199,7 +199,7 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index 2ebec26..a1d35e2 100644
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c
@@ -322,7 +322,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto intr_or_no_mm;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index ed82eda..ec995b0 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -350,7 +350,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *
mm = vma->vm_mm;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
if (mm->context.huge_pte_count && is_hugetlb_pte(pte))
@@ -361,7 +361,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *
__update_mmu_tsb_insert(mm, MM_TSB_BASE, PAGE_SHIFT,
address, pte_val(pte));
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
void flush_dcache_page(struct page *page)
@@ -661,7 +661,7 @@ void __flush_dcache_range(unsigned long start, unsigned long end)
EXPORT_SYMBOL(__flush_dcache_range);
/* get_new_mmu_context() uses "cache + 1". */
-DEFINE_SPINLOCK(ctx_alloc_lock);
+DEFINE_RAW_SPINLOCK(ctx_alloc_lock);
unsigned long tlb_context_cache = CTX_FIRST_VERSION - 1;
#define MAX_CTX_NR (1UL << CTX_NR_BITS)
#define CTX_BMAP_SLOTS BITS_TO_LONGS(MAX_CTX_NR)
@@ -683,7 +683,7 @@ void get_new_mmu_context(struct mm_struct *mm)
unsigned long orig_pgsz_bits;
int new_version;
- spin_lock(&ctx_alloc_lock);
+ raw_spin_lock(&ctx_alloc_lock);
orig_pgsz_bits = (mm->context.sparc64_ctx_val & CTX_PGSZ_MASK);
ctx = (tlb_context_cache + 1) & CTX_NR_MASK;
new_ctx = find_next_zero_bit(mmu_context_bmap, 1 << CTX_NR_BITS, ctx);
@@ -719,7 +719,7 @@ void get_new_mmu_context(struct mm_struct *mm)
out:
tlb_context_cache = new_ctx;
mm->context.sparc64_ctx_val = new_ctx | orig_pgsz_bits;
- spin_unlock(&ctx_alloc_lock);
+ raw_spin_unlock(&ctx_alloc_lock);
if (unlikely(new_version))
smp_new_mmu_context_version();
@@ -2721,7 +2721,7 @@ void hugetlb_setup(struct pt_regs *regs)
if (tlb_type == cheetah_plus) {
unsigned long ctx;
- spin_lock(&ctx_alloc_lock);
+ raw_spin_lock(&ctx_alloc_lock);
ctx = mm->context.sparc64_ctx_val;
ctx &= ~CTX_PGSZ_MASK;
ctx |= CTX_PGSZ_BASE << CTX_PGSZ0_SHIFT;
@@ -2742,7 +2742,7 @@ void hugetlb_setup(struct pt_regs *regs)
mm->context.sparc64_ctx_val = ctx;
on_each_cpu(context_reload, mm, 0);
}
- spin_unlock(&ctx_alloc_lock);
+ raw_spin_unlock(&ctx_alloc_lock);
}
}
#endif
diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c
index 2cc3bce..9eb10b4 100644
--- a/arch/sparc/mm/tsb.c
+++ b/arch/sparc/mm/tsb.c
@@ -73,7 +73,7 @@ void flush_tsb_user(struct tlb_batch *tb)
struct mm_struct *mm = tb->mm;
unsigned long nentries, base, flags;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
@@ -90,14 +90,14 @@ void flush_tsb_user(struct tlb_batch *tb)
__flush_tsb_one(tb, HPAGE_SHIFT, base, nentries);
}
#endif
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr)
{
unsigned long nentries, base, flags;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
@@ -114,7 +114,7 @@ void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr)
__flush_tsb_one_entry(base, vaddr, HPAGE_SHIFT, nentries);
}
#endif
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
#define HV_PGSZ_IDX_BASE HV_PGSZ_IDX_8K
@@ -392,7 +392,7 @@ retry_tsb_alloc:
* the lock and ask all other cpus running this address space
* to run tsb_context_switch() to see the new TSB table.
*/
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
old_tsb = mm->context.tsb_block[tsb_index].tsb;
old_cache_index =
@@ -407,7 +407,7 @@ retry_tsb_alloc:
*/
if (unlikely(old_tsb &&
(rss < mm->context.tsb_block[tsb_index].tsb_rss_limit))) {
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
kmem_cache_free(tsb_caches[new_cache_index], new_tsb);
return;
@@ -433,7 +433,7 @@ retry_tsb_alloc:
mm->context.tsb_block[tsb_index].tsb = new_tsb;
setup_tsb_params(mm, tsb_index, new_size);
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
/* If old_tsb is NULL, we're being invoked for the first time
* from init_new_context().
@@ -459,7 +459,7 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
#endif
unsigned int i;
- spin_lock_init(&mm->context.lock);
+ raw_spin_lock_init(&mm->context.lock);
mm->context.sparc64_ctx_val = 0UL;
@@ -523,12 +523,12 @@ void destroy_context(struct mm_struct *mm)
free_hot_cold_page(page, 0);
}
- spin_lock_irqsave(&ctx_alloc_lock, flags);
+ raw_spin_lock_irqsave(&ctx_alloc_lock, flags);
if (CTX_VALID(mm->context)) {
unsigned long nr = CTX_NRBITS(mm->context);
mmu_context_bmap[nr>>6] &= ~(1UL << (nr & 63));
}
- spin_unlock_irqrestore(&ctx_alloc_lock, flags);
+ raw_spin_unlock_irqrestore(&ctx_alloc_lock, flags);
}
diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
index 6c05712..40f30ac 100644
--- a/arch/tile/mm/fault.c
+++ b/arch/tile/mm/fault.c
@@ -357,7 +357,7 @@ static int handle_page_fault(struct pt_regs *regs,
* If we're in an interrupt, have no user context or are running in an
* atomic region then we must not take the fault.
*/
- if (in_atomic() || !mm) {
+ if (!mm || pagefault_disabled()) {
vma = NULL; /* happy compiler */
goto bad_area_nosemaphore;
}
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 5c3aef7..100a278 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -38,7 +38,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
* If the fault was during atomic operation, don't take the fault, just
* fail.
*/
- if (in_atomic())
+ if (pagefault_disabled())
goto out_nosemaphore;
if (is_user)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f67e839..edbb857 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -21,6 +21,7 @@ config X86_64
### Arch settings
config X86
def_bool y
+ select HAVE_PREEMPT_LAZY
select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
select HAVE_AOUT if X86_32
select HAVE_UNSTABLE_SCHED_CLOCK
@@ -179,8 +180,11 @@ config ARCH_MAY_HAVE_PC_FDC
def_bool y
depends on ISA_DMA_API
+config RWSEM_GENERIC_SPINLOCK
+ def_bool PREEMPT_RT_FULL
+
config RWSEM_XCHGADD_ALGORITHM
- def_bool y
+ def_bool !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT_FULL
config GENERIC_CALIBRATE_DELAY
def_bool y
@@ -470,7 +474,7 @@ config X86_MDFLD
select MFD_INTEL_MSIC
---help---
Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
- Internet Device(MID) platform.
+ Internet Device(MID) platform.
Unlike standard x86 PCs, Medfield does not have many legacy devices
nor standard legacy replacement devices/features. e.g. Medfield does
not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
@@ -817,7 +821,7 @@ config IOMMU_HELPER
config MAXSMP
bool "Enable Maximum number of SMP Processors and NUMA Nodes"
depends on X86_64 && SMP && DEBUG_KERNEL
- select CPUMASK_OFFSTACK
+ select CPUMASK_OFFSTACK if !PREEMPT_RT_FULL
---help---
Enable maximum number of CPUS and NUMA Nodes for this architecture.
If unsure, say N.
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index f80e668..3fbe870 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -252,14 +252,14 @@ static int ecb_encrypt(struct blkcipher_desc *desc,
err = blkcipher_walk_virt(desc, &walk);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_ecb_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
- nbytes & AES_BLOCK_MASK);
+ nbytes & AES_BLOCK_MASK);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -276,14 +276,14 @@ static int ecb_decrypt(struct blkcipher_desc *desc,
err = blkcipher_walk_virt(desc, &walk);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_ecb_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -300,14 +300,14 @@ static int cbc_encrypt(struct blkcipher_desc *desc,
err = blkcipher_walk_virt(desc, &walk);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_cbc_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK, walk.iv);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -324,14 +324,14 @@ static int cbc_decrypt(struct blkcipher_desc *desc,
err = blkcipher_walk_virt(desc, &walk);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_cbc_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK, walk.iv);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -364,18 +364,20 @@ static int ctr_crypt(struct blkcipher_desc *desc,
err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
+ kernel_fpu_begin();
aesni_ctr_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK, walk.iv);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
if (walk.nbytes) {
+ kernel_fpu_begin();
ctr_crypt_final(ctx, &walk);
+ kernel_fpu_end();
err = blkcipher_walk_done(desc, &walk, 0);
}
- kernel_fpu_end();
return err;
}
diff --git a/arch/x86/crypto/cast5_avx_glue.c b/arch/x86/crypto/cast5_avx_glue.c
index c663181..2d48e83 100644
--- a/arch/x86/crypto/cast5_avx_glue.c
+++ b/arch/x86/crypto/cast5_avx_glue.c
@@ -60,7 +60,7 @@ static inline void cast5_fpu_end(bool fpu_enabled)
static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
bool enc)
{
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct cast5_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
const unsigned int bsize = CAST5_BLOCK_SIZE;
unsigned int nbytes;
@@ -76,7 +76,7 @@ static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
u8 *wsrc = walk->src.virt.addr;
u8 *wdst = walk->dst.virt.addr;
- fpu_enabled = cast5_fpu_begin(fpu_enabled, nbytes);
+ fpu_enabled = cast5_fpu_begin(false, nbytes);
/* Process multi-block batch */
if (nbytes >= bsize * CAST5_PARALLEL_BLOCKS) {
@@ -104,10 +104,9 @@ static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
} while (nbytes >= bsize);
done:
+ cast5_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, walk, nbytes);
}
-
- cast5_fpu_end(fpu_enabled);
return err;
}
@@ -231,7 +230,7 @@ done:
static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -240,12 +239,11 @@ static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
while ((nbytes = walk.nbytes)) {
- fpu_enabled = cast5_fpu_begin(fpu_enabled, nbytes);
+ fpu_enabled = cast5_fpu_begin(false, nbytes);
nbytes = __cbc_decrypt(desc, &walk);
+ cast5_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- cast5_fpu_end(fpu_enabled);
return err;
}
@@ -315,7 +313,7 @@ done:
static int ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -324,13 +322,12 @@ static int ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
while ((nbytes = walk.nbytes) >= CAST5_BLOCK_SIZE) {
- fpu_enabled = cast5_fpu_begin(fpu_enabled, nbytes);
+ fpu_enabled = cast5_fpu_begin(false, nbytes);
nbytes = __ctr_crypt(desc, &walk);
+ cast5_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- cast5_fpu_end(fpu_enabled);
-
if (walk.nbytes) {
ctr_crypt_final(desc, &walk);
err = blkcipher_walk_done(desc, &walk, 0);
diff --git a/arch/x86/crypto/glue_helper.c b/arch/x86/crypto/glue_helper.c
index 432f1d76..4a2bd21 100644
--- a/arch/x86/crypto/glue_helper.c
+++ b/arch/x86/crypto/glue_helper.c
@@ -39,7 +39,7 @@ static int __glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
void *ctx = crypto_blkcipher_ctx(desc->tfm);
const unsigned int bsize = 128 / 8;
unsigned int nbytes, i, func_bytes;
- bool fpu_enabled = false;
+ bool fpu_enabled;
int err;
err = blkcipher_walk_virt(desc, walk);
@@ -49,7 +49,7 @@ static int __glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
u8 *wdst = walk->dst.virt.addr;
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- desc, fpu_enabled, nbytes);
+ desc, false, nbytes);
for (i = 0; i < gctx->num_funcs; i++) {
func_bytes = bsize * gctx->funcs[i].num_blocks;
@@ -71,10 +71,10 @@ static int __glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
}
done:
+ glue_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, walk, nbytes);
}
- glue_fpu_end(fpu_enabled);
return err;
}
@@ -194,7 +194,7 @@ int glue_cbc_decrypt_128bit(const struct common_glue_ctx *gctx,
struct scatterlist *src, unsigned int nbytes)
{
const unsigned int bsize = 128 / 8;
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -203,12 +203,12 @@ int glue_cbc_decrypt_128bit(const struct common_glue_ctx *gctx,
while ((nbytes = walk.nbytes)) {
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- desc, fpu_enabled, nbytes);
+ desc, false, nbytes);
nbytes = __glue_cbc_decrypt_128bit(gctx, desc, &walk);
+ glue_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- glue_fpu_end(fpu_enabled);
return err;
}
EXPORT_SYMBOL_GPL(glue_cbc_decrypt_128bit);
@@ -278,7 +278,7 @@ int glue_ctr_crypt_128bit(const struct common_glue_ctx *gctx,
struct scatterlist *src, unsigned int nbytes)
{
const unsigned int bsize = 128 / 8;
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -287,13 +287,12 @@ int glue_ctr_crypt_128bit(const struct common_glue_ctx *gctx,
while ((nbytes = walk.nbytes) >= bsize) {
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- desc, fpu_enabled, nbytes);
+ desc, false, nbytes);
nbytes = __glue_ctr_crypt_128bit(gctx, desc, &walk);
+ glue_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- glue_fpu_end(fpu_enabled);
-
if (walk.nbytes) {
glue_ctr_crypt_final_128bit(
gctx->funcs[gctx->num_funcs - 1].fn_u.ctr, desc, &walk);
@@ -348,7 +347,7 @@ int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
void *tweak_ctx, void *crypt_ctx)
{
const unsigned int bsize = 128 / 8;
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -361,21 +360,21 @@ int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
/* set minimum length to bsize, for tweak_fn */
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- desc, fpu_enabled,
+ desc, false,
nbytes < bsize ? bsize : nbytes);
-
/* calculate first value of T */
tweak_fn(tweak_ctx, walk.iv, walk.iv);
+ glue_fpu_end(fpu_enabled);
while (nbytes) {
+ fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
+ desc, false, nbytes);
nbytes = __glue_xts_crypt_128bit(gctx, crypt_ctx, desc, &walk);
+ glue_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
nbytes = walk.nbytes;
}
-
- glue_fpu_end(fpu_enabled);
-
return err;
}
EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit);
diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h
index 35e67a4..6ec0792 100644
--- a/arch/x86/include/asm/signal.h
+++ b/arch/x86/include/asm/signal.h
@@ -23,6 +23,19 @@ typedef struct {
unsigned long sig[_NSIG_WORDS];
} sigset_t;
+/*
+ * Because some traps use the IST stack, we must keep preemption
+ * disabled while calling do_trap(), but do_trap() may call
+ * force_sig_info() which will grab the signal spin_locks for the
+ * task, which in PREEMPT_RT_FULL are mutexes. By defining
+ * ARCH_RT_DELAYS_SIGNAL_SEND the force_sig_info() will set
+ * TIF_NOTIFY_RESUME and set up the signal to be sent on exit of the
+ * trap.
+ */
+#if defined(CONFIG_PREEMPT_RT_FULL) && defined(CONFIG_X86_64)
+#define ARCH_RT_DELAYS_SIGNAL_SEND
+#endif
+
#ifndef CONFIG_COMPAT
typedef sigset_t compat_sigset_t;
#endif
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
index 6a99859..64fb5cb 100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@ -57,7 +57,7 @@
*/
static __always_inline void boot_init_stack_canary(void)
{
- u64 canary;
+ u64 uninitialized_var(canary);
u64 tsc;
#ifdef CONFIG_X86_64
@@ -68,8 +68,16 @@ static __always_inline void boot_init_stack_canary(void)
* of randomness. The TSC only matters for very early init,
* there it already has some randomness on most systems. Later
* on during the bootup the random pool has true entropy too.
+ *
+ * For preempt-rt we need to weaken the randomness a bit, as
+ * we can't call into the random generator from atomic context
+ * due to locking constraints. We just leave canary
+ * uninitialized and use the TSC based randomness on top of
+ * it.
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
get_random_bytes(&canary, sizeof(canary));
+#endif
tsc = __native_read_tsc();
canary += tsc + (tsc << 32UL);
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 2781119..f08e527 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -30,6 +30,8 @@ struct thread_info {
__u32 cpu; /* current CPU */
int preempt_count; /* 0 => preemptable,
<0 => BUG */
+ int preempt_lazy_count; /* 0 => lazy preemptable,
+ <0 => BUG */
mm_segment_t addr_limit;
struct restart_block restart_block;
void __user *sysenter_return;
@@ -81,6 +83,7 @@ struct thread_info {
#define TIF_SYSCALL_EMU 6 /* syscall emulation active */
#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
#define TIF_SECCOMP 8 /* secure computing */
+#define TIF_NEED_RESCHED_LAZY 9 /* lazy rescheduling necessary */
#define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
#define TIF_UPROBE 12 /* breakpointed or singlestepping */
@@ -105,6 +108,7 @@ struct thread_info {
#define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
+#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
#define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
#define _TIF_UPROBE (1 << TIF_UPROBE)
@@ -154,6 +158,8 @@ struct thread_info {
#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
+#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
+
#define PREEMPT_ACTIVE 0x10000000
#ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index e63a5bd..5816e6a 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2396,7 +2396,8 @@ static bool io_apic_level_ack_pending(struct irq_cfg *cfg)
static inline bool ioapic_irqd_mask(struct irq_data *data, struct irq_cfg *cfg)
{
/* If we are moving the irq we need to mask it */
- if (unlikely(irqd_is_setaffinity_pending(data))) {
+ if (unlikely(irqd_is_setaffinity_pending(data) &&
+ !irqd_irq_inprogress(data))) {
mask_ioapic(cfg);
return true;
}
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 2861082..a36d9cf 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -33,6 +33,7 @@ void common(void) {
OFFSET(TI_status, thread_info, status);
OFFSET(TI_addr_limit, thread_info, addr_limit);
OFFSET(TI_preempt_count, thread_info, preempt_count);
+ OFFSET(TI_preempt_lazy_count, thread_info, preempt_lazy_count);
BLANK();
OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index b3218cd..3a7ab0b 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -18,6 +18,7 @@
#include <linux/rcupdate.h>
#include <linux/kobject.h>
#include <linux/uaccess.h>
+#include <linux/kthread.h>
#include <linux/kdebug.h>
#include <linux/kernel.h>
#include <linux/percpu.h>
@@ -41,6 +42,7 @@
#include <linux/debugfs.h>
#include <linux/irq_work.h>
#include <linux/export.h>
+#include <linux/jiffies.h>
#include <asm/processor.h>
#include <asm/mce.h>
@@ -1268,7 +1270,7 @@ void mce_log_therm_throt_event(__u64 status)
static unsigned long check_interval = 5 * 60; /* 5 minutes */
static DEFINE_PER_CPU(unsigned long, mce_next_interval); /* in jiffies */
-static DEFINE_PER_CPU(struct timer_list, mce_timer);
+static DEFINE_PER_CPU(struct hrtimer, mce_timer);
static unsigned long mce_adjust_timer_default(unsigned long interval)
{
@@ -1278,13 +1280,10 @@ static unsigned long mce_adjust_timer_default(unsigned long interval)
static unsigned long (*mce_adjust_timer)(unsigned long interval) =
mce_adjust_timer_default;
-static void mce_timer_fn(unsigned long data)
+static enum hrtimer_restart mce_timer_fn(struct hrtimer *timer)
{
- struct timer_list *t = &__get_cpu_var(mce_timer);
unsigned long iv;
- WARN_ON(smp_processor_id() != data);
-
if (mce_available(__this_cpu_ptr(&cpu_info))) {
machine_check_poll(MCP_TIMESTAMP,
&__get_cpu_var(mce_poll_banks));
@@ -1305,9 +1304,11 @@ static void mce_timer_fn(unsigned long data)
__this_cpu_write(mce_next_interval, iv);
/* Might have become 0 after CMCI storm subsided */
if (iv) {
- t->expires = jiffies + iv;
- add_timer_on(t, smp_processor_id());
+ hrtimer_forward_now(timer, ns_to_ktime(
+ jiffies_to_usecs(iv) * 1000ULL));
+ return HRTIMER_RESTART;
}
+ return HRTIMER_NORESTART;
}
/*
@@ -1315,28 +1316,37 @@ static void mce_timer_fn(unsigned long data)
*/
void mce_timer_kick(unsigned long interval)
{
- struct timer_list *t = &__get_cpu_var(mce_timer);
- unsigned long when = jiffies + interval;
+ struct hrtimer *t = &__get_cpu_var(mce_timer);
unsigned long iv = __this_cpu_read(mce_next_interval);
- if (timer_pending(t)) {
- if (time_before(when, t->expires))
- mod_timer_pinned(t, when);
+ if (hrtimer_active(t)) {
+ s64 exp;
+ s64 intv_us;
+
+ intv_us = jiffies_to_usecs(interval);
+ exp = ktime_to_us(hrtimer_expires_remaining(t));
+ if (intv_us < exp) {
+ hrtimer_cancel(t);
+ hrtimer_start_range_ns(t,
+ ns_to_ktime(intv_us * 1000),
+ 0, HRTIMER_MODE_REL_PINNED);
+ }
} else {
- t->expires = round_jiffies(when);
- add_timer_on(t, smp_processor_id());
+ hrtimer_start_range_ns(t,
+ ns_to_ktime(jiffies_to_usecs(interval) * 1000ULL),
+ 0, HRTIMER_MODE_REL_PINNED);
}
if (interval < iv)
__this_cpu_write(mce_next_interval, interval);
}
-/* Must not be called in IRQ context where del_timer_sync() can deadlock */
+/* Must not be called in IRQ context where hrtimer_cancel() can deadlock */
static void mce_timer_delete_all(void)
{
int cpu;
for_each_online_cpu(cpu)
- del_timer_sync(&per_cpu(mce_timer, cpu));
+ hrtimer_cancel(&per_cpu(mce_timer, cpu));
}
static void mce_do_trigger(struct work_struct *work)
@@ -1346,6 +1356,63 @@ static void mce_do_trigger(struct work_struct *work)
static DECLARE_WORK(mce_trigger_work, mce_do_trigger);
+static void __mce_notify_work(void)
+{
+ /* Not more than two messages every minute */
+ static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
+
+ /* wake processes polling /dev/mcelog */
+ wake_up_interruptible(&mce_chrdev_wait);
+
+ /*
+ * There is no risk of missing notifications because
+ * work_pending is always cleared before the function is
+ * executed.
+ */
+ if (mce_helper[0] && !work_pending(&mce_trigger_work))
+ schedule_work(&mce_trigger_work);
+
+ if (__ratelimit(&ratelimit))
+ pr_info(HW_ERR "Machine check events logged\n");
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+struct task_struct *mce_notify_helper;
+
+static int mce_notify_helper_thread(void *unused)
+{
+ while (1) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ if (kthread_should_stop())
+ break;
+ __mce_notify_work();
+ }
+ return 0;
+}
+
+static int mce_notify_work_init(void)
+{
+ mce_notify_helper = kthread_run(mce_notify_helper_thread, NULL,
+ "mce-notify");
+ if (!mce_notify_helper)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void mce_notify_work(void)
+{
+ wake_up_process(mce_notify_helper);
+}
+#else
+static void mce_notify_work(void)
+{
+ __mce_notify_work();
+}
+static inline int mce_notify_work_init(void) { return 0; }
+#endif
+
/*
* Notify the user(s) about new machine check events.
* Can be called from interrupt context, but not from machine check/NMI
@@ -1353,19 +1420,8 @@ static DECLARE_WORK(mce_trigger_work, mce_do_trigger);
*/
int mce_notify_irq(void)
{
- /* Not more than two messages every minute */
- static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
-
if (test_and_clear_bit(0, &mce_need_notify)) {
- /* wake processes polling /dev/mcelog */
- wake_up_interruptible(&mce_chrdev_wait);
-
- if (mce_helper[0])
- schedule_work(&mce_trigger_work);
-
- if (__ratelimit(&ratelimit))
- pr_info(HW_ERR "Machine check events logged\n");
-
+ mce_notify_work();
return 1;
}
return 0;
@@ -1636,7 +1692,7 @@ static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
}
}
-static void mce_start_timer(unsigned int cpu, struct timer_list *t)
+static void mce_start_timer(unsigned int cpu, struct hrtimer *t)
{
unsigned long iv = mce_adjust_timer(check_interval * HZ);
@@ -1645,16 +1701,17 @@ static void mce_start_timer(unsigned int cpu, struct timer_list *t)
if (mca_cfg.ignore_ce || !iv)
return;
- t->expires = round_jiffies(jiffies + iv);
- add_timer_on(t, smp_processor_id());
+ hrtimer_start_range_ns(t, ns_to_ktime(jiffies_to_usecs(iv) * 1000ULL),
+ 0, HRTIMER_MODE_REL_PINNED);
}
static void __mcheck_cpu_init_timer(void)
{
- struct timer_list *t = &__get_cpu_var(mce_timer);
+ struct hrtimer *t = &__get_cpu_var(mce_timer);
unsigned int cpu = smp_processor_id();
- setup_timer(t, mce_timer_fn, cpu);
+ hrtimer_init(t, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ t->function = mce_timer_fn;
mce_start_timer(cpu, t);
}
@@ -2329,6 +2386,8 @@ static void mce_disable_cpu(void *h)
if (!mce_available(__this_cpu_ptr(&cpu_info)))
return;
+ hrtimer_cancel(&__get_cpu_var(mce_timer));
+
if (!(action & CPU_TASKS_FROZEN))
cmci_clear();
for (i = 0; i < mca_cfg.banks; i++) {
@@ -2355,6 +2414,7 @@ static void mce_reenable_cpu(void *h)
if (b->init)
wrmsrl(MSR_IA32_MCx_CTL(i), b->ctl);
}
+ __mcheck_cpu_init_timer();
}
/* Get notified when a cpu comes on/off. Be hotplug friendly. */
@@ -2362,7 +2422,6 @@ static int
mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
- struct timer_list *t = &per_cpu(mce_timer, cpu);
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
@@ -2378,11 +2437,9 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
break;
case CPU_DOWN_PREPARE:
smp_call_function_single(cpu, mce_disable_cpu, &action, 1);
- del_timer_sync(t);
break;
case CPU_DOWN_FAILED:
smp_call_function_single(cpu, mce_reenable_cpu, &action, 1);
- mce_start_timer(cpu, t);
break;
}
@@ -2444,6 +2501,8 @@ static __init int mcheck_init_device(void)
/* register character device /dev/mcelog */
misc_register(&mce_chrdev_device);
+ err = mce_notify_work_init();
+
return err;
}
device_initcall_sync(mcheck_init_device);
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 15a569a..e491bfd 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -364,14 +364,22 @@ ENTRY(resume_kernel)
DISABLE_INTERRUPTS(CLBR_ANY)
cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
jnz restore_all
-need_resched:
movl TI_flags(%ebp), %ecx # need_resched set ?
testb $_TIF_NEED_RESCHED, %cl
+ jnz 1f
+
+ cmpl $0,TI_preempt_lazy_count(%ebp) # non-zero preempt_lazy_count ?
+ jnz restore_all
+ testl $_TIF_NEED_RESCHED_LAZY, %ecx
jz restore_all
- testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ?
+
+1: testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ?
jz restore_all
call preempt_schedule_irq
- jmp need_resched
+ movl TI_flags(%ebp), %ecx # need_resched set ?
+ testl $_TIF_NEED_RESCHED_MASK, %ecx
+ jnz 1b
+ jmp restore_all
END(resume_kernel)
#endif
CFI_ENDPROC
@@ -607,7 +615,7 @@ ENDPROC(system_call)
ALIGN
RING0_PTREGS_FRAME # can't unwind into user space anyway
work_pending:
- testb $_TIF_NEED_RESCHED, %cl
+ testl $_TIF_NEED_RESCHED_MASK, %ecx
jz work_notifysig
work_resched:
call schedule
@@ -620,7 +628,7 @@ work_resched:
andl $_TIF_WORK_MASK, %ecx # is there any work to be done other
# than syscall tracing?
jz restore_all
- testb $_TIF_NEED_RESCHED, %cl
+ testl $_TIF_NEED_RESCHED_MASK, %ecx
jnz work_resched
work_notifysig: # deal with pending signals and
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 9ce2567..abca4f4 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -658,8 +658,8 @@ sysret_check:
/* Handle reschedules */
/* edx: work, edi: workmask */
sysret_careful:
- bt $TIF_NEED_RESCHED,%edx
- jnc sysret_signal
+ testl $_TIF_NEED_RESCHED_MASK,%edx
+ jz sysret_signal
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
pushq_cfi %rdi
@@ -771,8 +771,8 @@ GLOBAL(int_with_check)
/* First do a reschedule test. */
/* edx: work, edi: workmask */
int_careful:
- bt $TIF_NEED_RESCHED,%edx
- jnc int_very_careful
+ testl $_TIF_NEED_RESCHED_MASK,%edx
+ jz int_very_careful
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
pushq_cfi %rdi
@@ -1071,8 +1071,8 @@ bad_iret:
/* edi: workmask, edx: work */
retint_careful:
CFI_RESTORE_STATE
- bt $TIF_NEED_RESCHED,%edx
- jnc retint_signal
+ testl $_TIF_NEED_RESCHED_MASK,%edx
+ jz retint_signal
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
pushq_cfi %rdi
@@ -1105,9 +1105,15 @@ retint_signal:
ENTRY(retint_kernel)
cmpl $0,TI_preempt_count(%rcx)
jnz retint_restore_args
- bt $TIF_NEED_RESCHED,TI_flags(%rcx)
+ bt $TIF_NEED_RESCHED,TI_flags(%rcx)
+ jc 1f
+
+ cmpl $0,TI_preempt_lazy_count(%rcx)
+ jnz retint_restore_args
+ bt $TIF_NEED_RESCHED_LAZY,TI_flags(%rcx)
jnc retint_restore_args
- bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */
+
+1: bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */
jnc retint_restore_args
call preempt_schedule_irq
jmp exit_intr
@@ -1341,6 +1347,7 @@ bad_gs:
jmp 2b
.previous
+#ifndef CONFIG_PREEMPT_RT_FULL
/* Call softirq on interrupt stack. Interrupts are off. */
ENTRY(call_softirq)
CFI_STARTPROC
@@ -1360,6 +1367,7 @@ ENTRY(call_softirq)
ret
CFI_ENDPROC
END(call_softirq)
+#endif
#ifdef CONFIG_XEN
zeroentry xen_hypervisor_callback xen_do_hypervisor_callback
@@ -1529,7 +1537,7 @@ paranoid_userspace:
movq %rsp,%rdi /* &pt_regs */
call sync_regs
movq %rax,%rsp /* switch stack for scheduling */
- testl $_TIF_NEED_RESCHED,%ebx
+ testl $_TIF_NEED_RESCHED_MASK,%ebx
jnz paranoid_schedule
movl %ebx,%edx /* arg3: thread flags */
TRACE_IRQS_ON
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 4186755..9da1bc7 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -149,6 +149,7 @@ void irq_ctx_init(int cpu)
cpu, per_cpu(hardirq_ctx, cpu), per_cpu(softirq_ctx, cpu));
}
+#ifndef CONFIG_PREEMPT_RT_FULL
asmlinkage void do_softirq(void)
{
unsigned long flags;
@@ -179,6 +180,7 @@ asmlinkage void do_softirq(void)
local_irq_restore(flags);
}
+#endif
bool handle_irq(unsigned irq, struct pt_regs *regs)
{
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index d04d3ec..831f247 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -88,7 +88,7 @@ bool handle_irq(unsigned irq, struct pt_regs *regs)
return true;
}
-
+#ifndef CONFIG_PREEMPT_RT_FULL
extern void call_softirq(void);
asmlinkage void do_softirq(void)
@@ -108,3 +108,4 @@ asmlinkage void do_softirq(void)
}
local_irq_restore(flags);
}
+#endif
diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c
index 1de84e3..3d21f7b 100644
--- a/arch/x86/kernel/irq_work.c
+++ b/arch/x86/kernel/irq_work.c
@@ -38,6 +38,7 @@ __visible void smp_trace_irq_work_interrupt(struct pt_regs *regs)
exiting_irq();
}
+#ifndef CONFIG_PREEMPT_RT_FULL
void arch_irq_work_raise(void)
{
#ifdef CONFIG_X86_LOCAL_APIC
@@ -48,3 +49,4 @@ void arch_irq_work_raise(void)
apic_wait_icr_idle();
#endif
}
+#endif
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 884f98f..6ce0537 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -36,6 +36,7 @@
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/kdebug.h>
+#include <linux/highmem.h>
#include <asm/pgtable.h>
#include <asm/ldt.h>
@@ -219,6 +220,35 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
}
EXPORT_SYMBOL_GPL(start_thread);
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p)
+{
+ int i;
+
+ /*
+ * Clear @prev's kmap_atomic mappings
+ */
+ for (i = 0; i < prev_p->kmap_idx; i++) {
+ int idx = i + KM_TYPE_NR * smp_processor_id();
+ pte_t *ptep = kmap_pte - idx;
+
+ kpte_clear_flush(ptep, __fix_to_virt(FIX_KMAP_BEGIN + idx));
+ }
+ /*
+ * Restore @next_p's kmap_atomic mappings
+ */
+ for (i = 0; i < next_p->kmap_idx; i++) {
+ int idx = i + KM_TYPE_NR * smp_processor_id();
+
+ if (!pte_none(next_p->kmap_pte[i]))
+ set_pte(kmap_pte - idx, next_p->kmap_pte[i]);
+ }
+}
+#else
+static inline void
+switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { }
+#endif
+
/*
* switch_to(x,y) should switch tasks from x to y.
@@ -298,6 +328,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
__switch_to_xtra(prev_p, next_p, tss);
+ switch_kmaps(prev_p, next_p);
+
/*
* Leave lazy mode, flushing any hypercalls made here.
* This must be done before restoring TLS segments so
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 9e5de68..ecfe089 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -739,6 +739,14 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
mce_notify_process();
#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+ if (unlikely(current->forced_info.si_signo)) {
+ struct task_struct *t = current;
+ force_sig_info(t->forced_info.si_signo, &t->forced_info, t);
+ t->forced_info.si_signo = 0;
+ }
+#endif
+
if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 8c8093b..6663bb5 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -86,9 +86,21 @@ static inline void conditional_sti(struct pt_regs *regs)
local_irq_enable();
}
-static inline void preempt_conditional_sti(struct pt_regs *regs)
+static inline void conditional_sti_ist(struct pt_regs *regs)
{
+#ifdef CONFIG_X86_64
+ /*
+ * X86_64 uses a per CPU stack on the IST for certain traps
+ * like int3. The task can not be preempted when using one
+ * of these stacks, thus preemption must be disabled, otherwise
+ * the stack can be corrupted if the task is scheduled out,
+ * and another task comes in and uses this stack.
+ *
+ * On x86_32 the task keeps its own stack and it is OK if the
+ * task schedules out.
+ */
inc_preempt_count();
+#endif
if (regs->flags & X86_EFLAGS_IF)
local_irq_enable();
}
@@ -99,11 +111,13 @@ static inline void conditional_cli(struct pt_regs *regs)
local_irq_disable();
}
-static inline void preempt_conditional_cli(struct pt_regs *regs)
+static inline void conditional_cli_ist(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
local_irq_disable();
+#ifdef CONFIG_X86_64
dec_preempt_count();
+#endif
}
static int __kprobes
@@ -236,9 +250,9 @@ dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
prev_state = exception_enter();
if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
X86_TRAP_SS, SIGBUS) != NOTIFY_STOP) {
- preempt_conditional_sti(regs);
+ conditional_sti_ist(regs);
do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL);
- preempt_conditional_cli(regs);
+ conditional_cli_ist(regs);
}
exception_exit(prev_state);
}
@@ -347,9 +361,9 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
* as we may switch to the interrupt stack.
*/
debug_stack_usage_inc();
- preempt_conditional_sti(regs);
+ conditional_sti_ist(regs);
do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
- preempt_conditional_cli(regs);
+ conditional_cli_ist(regs);
debug_stack_usage_dec();
exit:
exception_exit(prev_state);
@@ -455,12 +469,12 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
debug_stack_usage_inc();
/* It's safe to allow irq's after DR6 has been saved */
- preempt_conditional_sti(regs);
+ conditional_sti_ist(regs);
if (regs->flags & X86_VM_MASK) {
handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
X86_TRAP_DB);
- preempt_conditional_cli(regs);
+ conditional_cli_ist(regs);
debug_stack_usage_dec();
goto exit;
}
@@ -480,7 +494,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
si_code = get_si_code(tsk->thread.debugreg6);
if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
send_sigtrap(tsk, regs, error_code, si_code);
- preempt_conditional_cli(regs);
+ conditional_cli_ist(regs);
debug_stack_usage_dec();
exit:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 92af83d..e1b7b17 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5493,6 +5493,13 @@ int kvm_arch_init(void *opaque)
goto out;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
+ printk(KERN_ERR "RT requires X86_FEATURE_CONSTANT_TSC\n");
+ return -EOPNOTSUPP;
+ }
+#endif
+
r = kvm_mmu_module_init();
if (r)
goto out_free_percpu;
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 5b90bbcad9..b5c8e37 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1098,7 +1098,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code)
* If we're in an interrupt, have no user context or are running
* in an atomic region then we must not take the fault:
*/
- if (unlikely(in_atomic() || !mm)) {
+ if (unlikely(!mm || pagefault_disabled())) {
bad_area_nosemaphore(regs, error_code, address);
return;
}
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 4500142..7f96844 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -32,6 +32,7 @@ EXPORT_SYMBOL(kunmap);
*/
void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
+ pte_t pte = mk_pte(page, prot);
unsigned long vaddr;
int idx, type;
@@ -45,7 +46,10 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
BUG_ON(!pte_none(*(kmap_pte-idx)));
- set_pte(kmap_pte-idx, mk_pte(page, prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = pte;
+#endif
+ set_pte(kmap_pte-idx, pte);
arch_flush_lazy_mmu_mode();
return (void *)vaddr;
@@ -88,6 +92,9 @@ void __kunmap_atomic(void *kvaddr)
* is a bad idea also, in case the page changes cacheability
* attributes or becomes a protected page in a hypervisor.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = __pte(0);
+#endif
kpte_clear_flush(kmap_pte-idx, vaddr);
kmap_atomic_idx_pop();
arch_flush_lazy_mmu_mode();
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index 7b179b4..62377d6 100644
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -56,6 +56,7 @@ EXPORT_SYMBOL_GPL(iomap_free);
void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
{
+ pte_t pte = pfn_pte(pfn, prot);
unsigned long vaddr;
int idx, type;
@@ -64,7 +65,12 @@ void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
+ WARN_ON(!pte_none(*(kmap_pte - idx)));
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = pte;
+#endif
+ set_pte(kmap_pte - idx, pte);
arch_flush_lazy_mmu_mode();
return (void *)vaddr;
@@ -110,6 +116,9 @@ iounmap_atomic(void __iomem *kvaddr)
* is a bad idea also, in case the page changes cacheability
* attributes or becomes a protected page in a hypervisor.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = __pte(0);
+#endif
kpte_clear_flush(kmap_pte-idx, vaddr);
kmap_atomic_idx_pop();
}
diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c
index 70fa7bc..ff5c9c7 100644
--- a/arch/xtensa/mm/fault.c
+++ b/arch/xtensa/mm/fault.c
@@ -57,7 +57,7 @@ void do_page_fault(struct pt_regs *regs)
/* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm) {
+ if (!mm || pagefault_disabled()) {
bad_page_fault(regs, address, SIGSEGV);
return;
}
diff --git a/block/blk-core.c b/block/blk-core.c
index fce4b93..f703f97 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -232,7 +232,7 @@ EXPORT_SYMBOL(blk_delay_queue);
**/
void blk_start_queue(struct request_queue *q)
{
- WARN_ON(!irqs_disabled());
+ WARN_ON_NONRT(!irqs_disabled());
queue_flag_clear(QUEUE_FLAG_STOPPED, q);
__blk_run_queue(q);
@@ -2925,7 +2925,7 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth,
blk_run_queue_async(q);
else
__blk_run_queue(q);
- spin_unlock(q->queue_lock);
+ spin_unlock_irq(q->queue_lock);
}
static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule)
@@ -2973,7 +2973,6 @@ EXPORT_SYMBOL(blk_check_plugged);
void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
{
struct request_queue *q;
- unsigned long flags;
struct request *rq;
LIST_HEAD(list);
unsigned int depth;
@@ -2991,11 +2990,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
q = NULL;
depth = 0;
- /*
- * Save and disable interrupts here, to avoid doing it for every
- * queue lock we have to take.
- */
- local_irq_save(flags);
while (!list_empty(&list)) {
rq = list_entry_rq(list.next);
list_del_init(&rq->queuelist);
@@ -3008,7 +3002,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
queue_unplugged(q, depth, from_schedule);
q = rq->q;
depth = 0;
- spin_lock(q->queue_lock);
+ spin_lock_irq(q->queue_lock);
}
/*
@@ -3035,8 +3029,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
*/
if (q)
queue_unplugged(q, depth, from_schedule);
-
- local_irq_restore(flags);
}
void blk_finish_plug(struct blk_plug *plug)
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 46cd7bd..899d3e4 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -8,6 +8,7 @@
#include <linux/blkdev.h>
#include <linux/bootmem.h> /* for max_pfn/max_low_pfn */
#include <linux/slab.h>
+#include <linux/delay.h>
#include "blk.h"
@@ -110,7 +111,7 @@ static void ioc_release_fn(struct work_struct *work)
spin_unlock(q->queue_lock);
} else {
spin_unlock_irqrestore(&ioc->lock, flags);
- cpu_relax();
+ cpu_chill();
spin_lock_irqsave_nested(&ioc->lock, flags, 1);
}
}
@@ -188,7 +189,7 @@ retry:
spin_unlock(icq->q->queue_lock);
} else {
spin_unlock_irqrestore(&ioc->lock, flags);
- cpu_relax();
+ cpu_chill();
goto retry;
}
}
diff --git a/block/blk-iopoll.c b/block/blk-iopoll.c
index 4b8d9b54..15b4f08 100644
--- a/block/blk-iopoll.c
+++ b/block/blk-iopoll.c
@@ -38,6 +38,7 @@ void blk_iopoll_sched(struct blk_iopoll *iop)
list_add_tail(&iop->list, &__get_cpu_var(blk_cpu_iopoll));
__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
EXPORT_SYMBOL(blk_iopoll_sched);
@@ -135,6 +136,7 @@ static void blk_iopoll_softirq(struct softirq_action *h)
__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
}
/**
@@ -204,6 +206,7 @@ static int blk_iopoll_cpu_notify(struct notifier_block *self,
&__get_cpu_var(blk_cpu_iopoll));
__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
}
return NOTIFY_OK;
diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index ec9e606..814b3db 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -51,6 +51,7 @@ static void trigger_softirq(void *data)
raise_softirq_irqoff(BLOCK_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
/*
@@ -93,6 +94,7 @@ static int blk_cpu_notify(struct notifier_block *self, unsigned long action,
&__get_cpu_var(blk_cpu_done));
raise_softirq_irqoff(BLOCK_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
}
return NOTIFY_OK;
@@ -150,6 +152,7 @@ do_local:
goto do_local;
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
/**
diff --git a/crypto/algapi.c b/crypto/algapi.c
index 7a1ae87..5013cad 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -684,13 +684,13 @@ EXPORT_SYMBOL_GPL(crypto_spawn_tfm2);
int crypto_register_notifier(struct notifier_block *nb)
{
- return blocking_notifier_chain_register(&crypto_chain, nb);
+ return srcu_notifier_chain_register(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_register_notifier);
int crypto_unregister_notifier(struct notifier_block *nb)
{
- return blocking_notifier_chain_unregister(&crypto_chain, nb);
+ return srcu_notifier_chain_unregister(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
diff --git a/crypto/api.c b/crypto/api.c
index a2b39c5..9d68122 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -31,7 +31,7 @@ EXPORT_SYMBOL_GPL(crypto_alg_list);
DECLARE_RWSEM(crypto_alg_sem);
EXPORT_SYMBOL_GPL(crypto_alg_sem);
-BLOCKING_NOTIFIER_HEAD(crypto_chain);
+SRCU_NOTIFIER_HEAD(crypto_chain);
EXPORT_SYMBOL_GPL(crypto_chain);
static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
@@ -236,10 +236,10 @@ int crypto_probing_notify(unsigned long val, void *v)
{
int ok;
- ok = blocking_notifier_call_chain(&crypto_chain, val, v);
+ ok = srcu_notifier_call_chain(&crypto_chain, val, v);
if (ok == NOTIFY_DONE) {
request_module("cryptomgr");
- ok = blocking_notifier_call_chain(&crypto_chain, val, v);
+ ok = srcu_notifier_call_chain(&crypto_chain, val, v);
}
return ok;
diff --git a/crypto/internal.h b/crypto/internal.h
index bd39bfc..a5db167 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -48,7 +48,7 @@ struct crypto_larval {
extern struct list_head crypto_alg_list;
extern struct rw_semaphore crypto_alg_sem;
-extern struct blocking_notifier_head crypto_chain;
+extern struct srcu_notifier_head crypto_chain;
#ifdef CONFIG_PROC_FS
void __init crypto_init_proc(void);
@@ -142,7 +142,7 @@ static inline int crypto_is_moribund(struct crypto_alg *alg)
static inline void crypto_notify(unsigned long val, void *v)
{
- blocking_notifier_call_chain(&crypto_chain, val, v);
+ srcu_notifier_call_chain(&crypto_chain, val, v);
}
#endif /* _CRYPTO_INTERNAL_H */
diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index 90e846f..411f68d 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -235,7 +235,7 @@ ACPI_EXTERN u8 acpi_gbl_global_lock_pending;
* interrupt level
*/
ACPI_EXTERN acpi_spinlock acpi_gbl_gpe_lock; /* For GPE data structs and registers */
-ACPI_EXTERN acpi_spinlock acpi_gbl_hardware_lock; /* For ACPI H/W except GPE registers */
+ACPI_EXTERN acpi_raw_spinlock acpi_gbl_hardware_lock; /* For ACPI H/W except GPE registers */
ACPI_EXTERN acpi_spinlock acpi_gbl_reference_count_lock;
/* Mutex for _OSI support */
diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c
index 8d2e866..221c567 100644
--- a/drivers/acpi/acpica/hwregs.c
+++ b/drivers/acpi/acpica/hwregs.c
@@ -269,14 +269,14 @@ acpi_status acpi_hw_clear_acpi_status(void)
ACPI_BITMASK_ALL_FIXED_STATUS,
ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
- lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+ raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags);
/* Clear the fixed events in PM1 A/B */
status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
ACPI_BITMASK_ALL_FIXED_STATUS);
- acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
+ raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags);
if (ACPI_FAILURE(status))
goto exit;
diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c
index 5ee7a81..4c4b0cc 100644
--- a/drivers/acpi/acpica/hwxface.c
+++ b/drivers/acpi/acpica/hwxface.c
@@ -365,7 +365,7 @@ acpi_status acpi_write_bit_register(u32 register_id, u32 value)
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
- lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+ raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags);
/*
* At this point, we know that the parent register is one of the
@@ -426,7 +426,7 @@ acpi_status acpi_write_bit_register(u32 register_id, u32 value)
unlock_and_exit:
- acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
+ raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags);
return_ACPI_STATUS(status);
}
diff --git a/drivers/acpi/acpica/utmutex.c b/drivers/acpi/acpica/utmutex.c
index 08c3232..2f4ed8b 100644
--- a/drivers/acpi/acpica/utmutex.c
+++ b/drivers/acpi/acpica/utmutex.c
@@ -88,7 +88,7 @@ acpi_status acpi_ut_mutex_initialize(void)
return_ACPI_STATUS (status);
}
- status = acpi_os_create_lock (&acpi_gbl_hardware_lock);
+ status = acpi_os_create_raw_lock (&acpi_gbl_hardware_lock);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (status);
}
@@ -141,7 +141,7 @@ void acpi_ut_mutex_terminate(void)
/* Delete the spinlocks */
acpi_os_delete_lock(acpi_gbl_gpe_lock);
- acpi_os_delete_lock(acpi_gbl_hardware_lock);
+ acpi_os_delete_raw_lock(acpi_gbl_hardware_lock);
acpi_os_delete_lock(acpi_gbl_reference_count_lock);
/* Delete the reader/writer lock */
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index b603720..2afbd46 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -678,9 +678,9 @@ unsigned int ata_sff_data_xfer_noirq(struct ata_device *dev, unsigned char *buf,
unsigned long flags;
unsigned int consumed;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
consumed = ata_sff_data_xfer32(dev, buf, buflen, rw);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return consumed;
}
@@ -719,7 +719,7 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
unsigned long flags;
/* FIXME: use a bounce buffer */
- local_irq_save(flags);
+ local_irq_save_nort(flags);
buf = kmap_atomic(page);
/* do the actual data transfer */
@@ -727,7 +727,7 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
do_write);
kunmap_atomic(buf);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
} else {
buf = page_address(page);
ap->ops->sff_data_xfer(qc->dev, buf + offset, qc->sect_size,
@@ -864,7 +864,7 @@ next_sg:
unsigned long flags;
/* FIXME: use bounce buffer */
- local_irq_save(flags);
+ local_irq_save_nort(flags);
buf = kmap_atomic(page);
/* do the actual data transfer */
@@ -872,7 +872,7 @@ next_sg:
count, rw);
kunmap_atomic(buf);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
} else {
buf = page_address(page);
consumed = ap->ops->sff_data_xfer(dev, buf + offset,
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 7a744d3..ddcbcad 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -673,9 +673,12 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
preempt_disable();
/* if over the trickle threshold, use only 1 in 4096 samples */
if (input_pool.entropy_count > trickle_thresh &&
- ((__this_cpu_inc_return(trickle_count) - 1) & 0xfff))
- goto out;
+ ((__this_cpu_inc_return(trickle_count) - 1) & 0xfff)) {
+ preempt_enable();
+ return;
+ }
+ preempt_enable();
sample.jiffies = jiffies;
sample.cycles = random_get_entropy();
sample.num = num;
@@ -716,8 +719,6 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
credit_entropy_bits(&input_pool,
min_t(int, fls(delta>>1), 11));
}
-out:
- preempt_enable();
}
void add_input_randomness(unsigned int type, unsigned int code,
@@ -738,18 +739,16 @@ EXPORT_SYMBOL_GPL(add_input_randomness);
static DEFINE_PER_CPU(struct fast_pool, irq_randomness);
-void add_interrupt_randomness(int irq, int irq_flags)
+void add_interrupt_randomness(int irq, int irq_flags, __u64 ip)
{
struct entropy_store *r;
struct fast_pool *fast_pool = &__get_cpu_var(irq_randomness);
- struct pt_regs *regs = get_irq_regs();
unsigned long now = jiffies;
__u32 input[4], cycles = random_get_entropy();
input[0] = cycles ^ jiffies;
input[1] = irq;
- if (regs) {
- __u64 ip = instruction_pointer(regs);
+ if (ip) {
input[2] = ip;
input[3] = ip >> 32;
}
@@ -763,7 +762,11 @@ void add_interrupt_randomness(int irq, int irq_flags)
fast_pool->last = now;
r = nonblocking_pool.initialized ? &input_pool : &nonblocking_pool;
+#ifndef CONFIG_PREEMPT_RT_FULL
__mix_pool_bytes(r, &fast_pool->pool, sizeof(fast_pool->pool), NULL);
+#else
+ mix_pool_bytes(r, &fast_pool->pool, sizeof(fast_pool->pool), NULL);
+#endif
/*
* If we don't have a valid cycle counter, and we see
* back-to-back timer interrupts, then skip giving credit for
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 8a61872..a00dfaf 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -23,8 +23,7 @@
* this 32 bit free-running counter. the second channel is not used.
*
* - The third channel may be used to provide a 16-bit clockevent
- * source, used in either periodic or oneshot mode. This runs
- * at 32 KiHZ, and can handle delays of up to two seconds.
+ * source, used in either periodic or oneshot mode.
*
* A boot clocksource and clockevent source are also currently needed,
* unless the relevant platforms (ARM/AT91, AVR32/AT32) are changed so
@@ -74,6 +73,7 @@ static struct clocksource clksrc = {
struct tc_clkevt_device {
struct clock_event_device clkevt;
struct clk *clk;
+ u32 freq;
void __iomem *regs;
};
@@ -82,13 +82,6 @@ static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt)
return container_of(clkevt, struct tc_clkevt_device, clkevt);
}
-/* For now, we always use the 32K clock ... this optimizes for NO_HZ,
- * because using one of the divided clocks would usually mean the
- * tick rate can never be less than several dozen Hz (vs 0.5 Hz).
- *
- * A divided clock could be good for high resolution timers, since
- * 30.5 usec resolution can seem "low".
- */
static u32 timer_clock;
static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
@@ -111,11 +104,12 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
case CLOCK_EVT_MODE_PERIODIC:
clk_enable(tcd->clk);
- /* slow clock, count up to RC, then irq and restart */
+ /* count up to RC, then irq and restart */
__raw_writel(timer_clock
| ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
regs + ATMEL_TC_REG(2, CMR));
- __raw_writel((32768 + HZ/2) / HZ, tcaddr + ATMEL_TC_REG(2, RC));
+ __raw_writel((tcd->freq + HZ/2)/HZ,
+ tcaddr + ATMEL_TC_REG(2, RC));
/* Enable clock and interrupts on RC compare */
__raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
@@ -128,7 +122,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
case CLOCK_EVT_MODE_ONESHOT:
clk_enable(tcd->clk);
- /* slow clock, count up to RC, then irq and stop */
+ /* count up to RC, then irq and stop */
__raw_writel(timer_clock | ATMEL_TC_CPCSTOP
| ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
regs + ATMEL_TC_REG(2, CMR));
@@ -157,8 +151,12 @@ static struct tc_clkevt_device clkevt = {
.name = "tc_clkevt",
.features = CLOCK_EVT_FEAT_PERIODIC
| CLOCK_EVT_FEAT_ONESHOT,
+#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
/* Should be lower than at91rm9200's system timer */
.rating = 125,
+#else
+ .rating = 200,
+#endif
.set_next_event = tc_next_event,
.set_mode = tc_mode,
},
@@ -184,8 +182,9 @@ static struct irqaction tc_irqaction = {
.handler = ch2_irq,
};
-static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static void __init setup_clkevents(struct atmel_tc *tc, int divisor_idx)
{
+ unsigned divisor = atmel_tc_divisors[divisor_idx];
struct clk *t2_clk = tc->clk[2];
int irq = tc->irq[2];
@@ -193,11 +192,15 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
clkevt.clk = t2_clk;
tc_irqaction.dev_id = &clkevt;
- timer_clock = clk32k_divisor_idx;
+ timer_clock = divisor_idx;
+ if (!divisor)
+ clkevt.freq = 32768;
+ else
+ clkevt.freq = clk_get_rate(t2_clk) / divisor;
clkevt.clkevt.cpumask = cpumask_of(0);
- clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+ clockevents_config_and_register(&clkevt.clkevt, clkevt.freq, 1, 0xffff);
setup_irq(irq, &tc_irqaction);
}
@@ -322,8 +325,11 @@ static int __init tcb_clksrc_init(void)
clocksource_register_hz(&clksrc, divided_rate);
/* channel 2: periodic and oneshot timer support */
+#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
setup_clkevents(tc, clk32k_divisor_idx);
-
+#else
+ setup_clkevents(tc, best_divisor_idx);
+#endif
return 0;
}
arch_initcall(tcb_clksrc_init);
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index f92da0a..434ea84 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -628,11 +628,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
* code gets preempted or delayed for some reason.
*/
for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
- /* Disable preemption to make it very likely to
- * succeed in the first iteration even on PREEMPT_RT kernel.
- */
- preempt_disable();
-
/* Get system timestamp before query. */
stime = ktime_get();
@@ -644,8 +639,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
if (!drm_timestamp_monotonic)
mono_time_offset = ktime_get_monotonic_offset();
- preempt_enable();
-
/* Return as no-op if scanout query unsupported or failed. */
if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b00b32c..aaeac32 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4792,7 +4792,7 @@ static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
if (!mutex_is_locked(mutex))
return false;
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES)
+#if (defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES)) && !defined(CONFIG_PREEMPT_RT_BASE)
return mutex->owner == task;
#else
/* Since UP may be pre-empted, we cannot assume that we own the lock */
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index bf34577..979a6ea 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1129,7 +1129,9 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
goto err;
}
+#ifndef CONFIG_PREEMPT_RT_BASE
trace_i915_gem_ring_dispatch(ring, intel_ring_get_seqno(ring), flags);
+#endif
i915_gem_execbuffer_move_to_active(&eb->objects, vm, ring);
i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 9967a6f..2f66478 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -879,15 +879,12 @@ omap_i2c_isr(int irq, void *dev_id)
u16 mask;
u16 stat;
- spin_lock(&dev->lock);
- mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+ mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
if (stat & mask)
ret = IRQ_WAKE_THREAD;
- spin_unlock(&dev->lock);
-
return ret;
}
diff --git a/drivers/ide/alim15x3.c b/drivers/ide/alim15x3.c
index 36f76e2..394f142f 100644
--- a/drivers/ide/alim15x3.c
+++ b/drivers/ide/alim15x3.c
@@ -234,7 +234,7 @@ static int init_chipset_ali15x3(struct pci_dev *dev)
isa_dev = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, NULL);
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (m5229_revision < 0xC2) {
/*
@@ -325,7 +325,7 @@ out:
}
pci_dev_put(north);
pci_dev_put(isa_dev);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return 0;
}
diff --git a/drivers/ide/hpt366.c b/drivers/ide/hpt366.c
index 696b6c1..0d0a966 100644
--- a/drivers/ide/hpt366.c
+++ b/drivers/ide/hpt366.c
@@ -1241,7 +1241,7 @@ static int init_dma_hpt366(ide_hwif_t *hwif,
dma_old = inb(base + 2);
- local_irq_save(flags);
+ local_irq_save_nort(flags);
dma_new = dma_old;
pci_read_config_byte(dev, hwif->channel ? 0x4b : 0x43, &masterdma);
@@ -1252,7 +1252,7 @@ static int init_dma_hpt366(ide_hwif_t *hwif,
if (dma_new != dma_old)
outb(dma_new, base + 2);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
printk(KERN_INFO " %s: BM-DMA at 0x%04lx-0x%04lx\n",
hwif->name, base, base + 7);
diff --git a/drivers/ide/ide-io-std.c b/drivers/ide/ide-io-std.c
index 1976397..4169433 100644
--- a/drivers/ide/ide-io-std.c
+++ b/drivers/ide/ide-io-std.c
@@ -175,7 +175,7 @@ void ide_input_data(ide_drive_t *drive, struct ide_cmd *cmd, void *buf,
unsigned long uninitialized_var(flags);
if ((io_32bit & 2) && !mmio) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
ata_vlb_sync(io_ports->nsect_addr);
}
@@ -186,7 +186,7 @@ void ide_input_data(ide_drive_t *drive, struct ide_cmd *cmd, void *buf,
insl(data_addr, buf, words);
if ((io_32bit & 2) && !mmio)
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
if (((len + 1) & 3) < 2)
return;
@@ -219,7 +219,7 @@ void ide_output_data(ide_drive_t *drive, struct ide_cmd *cmd, void *buf,
unsigned long uninitialized_var(flags);
if ((io_32bit & 2) && !mmio) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
ata_vlb_sync(io_ports->nsect_addr);
}
@@ -230,7 +230,7 @@ void ide_output_data(ide_drive_t *drive, struct ide_cmd *cmd, void *buf,
outsl(data_addr, buf, words);
if ((io_32bit & 2) && !mmio)
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
if (((len + 1) & 3) < 2)
return;
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 177db6d..079ae6b 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -659,7 +659,7 @@ void ide_timer_expiry (unsigned long data)
/* disable_irq_nosync ?? */
disable_irq(hwif->irq);
/* local CPU only, as if we were handling an interrupt */
- local_irq_disable();
+ local_irq_disable_nort();
if (hwif->polling) {
startstop = handler(drive);
} else if (drive_is_ready(drive)) {
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 376f2dc..f014dd1 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -129,12 +129,12 @@ int __ide_wait_stat(ide_drive_t *drive, u8 good, u8 bad,
if ((stat & ATA_BUSY) == 0)
break;
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
*rstat = stat;
return -EBUSY;
}
}
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
/*
* Allow status to settle, then read it again.
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 2a744a9..0964500 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -196,10 +196,10 @@ static void do_identify(ide_drive_t *drive, u8 cmd, u16 *id)
int bswap = 1;
/* local CPU only; some systems need this */
- local_irq_save(flags);
+ local_irq_save_nort(flags);
/* read 512 bytes of id info */
hwif->tp_ops->input_data(drive, NULL, id, SECTOR_SIZE);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
drive->dev_flags |= IDE_DFLAG_ID_READ;
#ifdef DEBUG
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index dabb88b..2cecea7 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -250,7 +250,7 @@ void ide_pio_bytes(ide_drive_t *drive, struct ide_cmd *cmd,
page_is_high = PageHighMem(page);
if (page_is_high)
- local_irq_save(flags);
+ local_irq_save_nort(flags);
buf = kmap_atomic(page) + offset;
@@ -271,7 +271,7 @@ void ide_pio_bytes(ide_drive_t *drive, struct ide_cmd *cmd,
kunmap_atomic(buf);
if (page_is_high)
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
len -= nr_bytes;
}
@@ -414,7 +414,7 @@ static ide_startstop_t pre_task_out_intr(ide_drive_t *drive,
}
if ((drive->dev_flags & IDE_DFLAG_UNMASK) == 0)
- local_irq_disable();
+ local_irq_disable_nort();
ide_set_handler(drive, &task_pio_intr, WAIT_WORSTCASE);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index cecb98a..3800ef5 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -783,7 +783,7 @@ void ipoib_mcast_restart_task(struct work_struct *work)
ipoib_mcast_stop_thread(dev, 0);
- local_irq_save(flags);
+ local_irq_save_nort(flags);
netif_addr_lock(dev);
spin_lock(&priv->lock);
@@ -865,7 +865,7 @@ void ipoib_mcast_restart_task(struct work_struct *work)
spin_unlock(&priv->lock);
netif_addr_unlock(dev);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
/* We have to cancel outside of the spinlock */
list_for_each_entry_safe(mcast, tmcast, &remove_list, list) {
diff --git a/drivers/input/gameport/gameport.c b/drivers/input/gameport/gameport.c
index 922a7fe..b4fe94b 100644
--- a/drivers/input/gameport/gameport.c
+++ b/drivers/input/gameport/gameport.c
@@ -87,12 +87,12 @@ static int gameport_measure_speed(struct gameport *gameport)
tx = 1 << 30;
for(i = 0; i < 50; i++) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
GET_TIME(t1);
for (t = 0; t < 50; t++) gameport_read(gameport);
GET_TIME(t2);
GET_TIME(t3);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
udelay(i * 10);
if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
}
@@ -111,11 +111,11 @@ static int gameport_measure_speed(struct gameport *gameport)
tx = 1 << 30;
for(i = 0; i < 50; i++) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
rdtscl(t1);
for (t = 0; t < 50; t++) gameport_read(gameport);
rdtscl(t2);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
udelay(i * 10);
if (t2 - t1 < tx) tx = t2 - t1;
}
diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
index 49794b4..3d7245d 100644
--- a/drivers/leds/trigger/Kconfig
+++ b/drivers/leds/trigger/Kconfig
@@ -61,7 +61,7 @@ config LEDS_TRIGGER_BACKLIGHT
config LEDS_TRIGGER_CPU
bool "LED CPU Trigger"
- depends on LEDS_TRIGGERS
+ depends on LEDS_TRIGGERS && !PREEMPT_RT_BASE
help
This allows LEDs to be controlled by active CPUs. This shows
the active CPUs across an array of LEDs so you can see which
diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig
index f950c9d..5eb76dd 100644
--- a/drivers/md/bcache/Kconfig
+++ b/drivers/md/bcache/Kconfig
@@ -1,6 +1,7 @@
config BCACHE
tristate "Block device as cache"
+ depends on !PREEMPT_RT_FULL
---help---
Allows a block device to be used as cache for other devices; uses
a btree for indexing and the layout is optimized for SSDs.
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index a562d5a..c147f06 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1813,14 +1813,14 @@ static void dm_request_fn(struct request_queue *q)
if (map_request(ti, clone, md))
goto requeued;
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
spin_lock(q->queue_lock);
}
goto out;
requeued:
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
spin_lock(q->queue_lock);
delay_and_out:
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 3ecfb06..ab00c1e 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1541,8 +1541,9 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
struct raid5_percpu *percpu;
unsigned long cpu;
- cpu = get_cpu();
+ cpu = get_cpu_light();
percpu = per_cpu_ptr(conf->percpu, cpu);
+ spin_lock(&percpu->lock);
if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
ops_run_biofill(sh);
overlap_clear++;
@@ -1594,7 +1595,8 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
if (test_and_clear_bit(R5_Overlap, &dev->flags))
wake_up(&sh->raid_conf->wait_for_overlap);
}
- put_cpu();
+ spin_unlock(&percpu->lock);
+ put_cpu_light();
}
static int grow_one_stripe(struct r5conf *conf)
@@ -5456,6 +5458,7 @@ static int raid5_alloc_percpu(struct r5conf *conf)
__func__, cpu);
break;
}
+ spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock);
}
put_online_cpus();
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 2113ffa..0a5e1e1 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -444,6 +444,7 @@ struct r5conf {
int recovery_disabled;
/* per cpu variables */
struct raid5_percpu {
+ spinlock_t lock; /* Protection for -RT */
struct page *spare_page; /* Used when checking P/Q in raid6 */
void *scribble; /* space for constructing buffer
* lists and performing address
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 4dc11ca..c2d3eb7 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -63,6 +63,7 @@ config ATMEL_PWM
config ATMEL_TCLIB
bool "Atmel AT32/AT91 Timer/Counter Library"
depends on (AVR32 || ARCH_AT91)
+ default y if PREEMPT_RT_FULL
help
Select this if you want a library to allocate the Timer/Counter
blocks found on many Atmel processors. This facilitates using
@@ -78,8 +79,7 @@ config ATMEL_TCB_CLKSRC
are combined to make a single 32-bit timer.
When GENERIC_CLOCKEVENTS is defined, the third timer channel
- may be used as a clock event device supporting oneshot mode
- (delays of up to two seconds) based on the 32 KiHz clock.
+ may be used as a clock event device supporting oneshot mode.
config ATMEL_TCB_CLKSRC_BLOCK
int
@@ -93,6 +93,15 @@ config ATMEL_TCB_CLKSRC_BLOCK
TC can be used for other purposes, such as PWM generation and
interval timing.
+config ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
+ bool "TC Block use 32 KiHz clock"
+ depends on ATMEL_TCB_CLKSRC
+ default y if !PREEMPT_RT_FULL
+ help
+ Select this to use 32 KiHz base clock rate as TC block clock
+ source for clock events.
+
+
config DUMMY_IRQ
tristate "Dummy IRQ handler"
default n
@@ -122,6 +131,35 @@ config IBM_ASM
for information on the specific driver level and support statement
for your IBM server.
+config HWLAT_DETECTOR
+ tristate "Testing module to detect hardware-induced latencies"
+ depends on DEBUG_FS
+ depends on RING_BUFFER
+ default m
+ ---help---
+ A simple hardware latency detector. Use this module to detect
+ large latencies introduced by the behavior of the underlying
+ system firmware external to Linux. We do this using periodic
+ use of stop_machine to grab all available CPUs and measure
+ for unexplainable gaps in the CPU timestamp counter(s). By
+ default, the module is not enabled until the "enable" file
+ within the "hwlat_detector" debugfs directory is toggled.
+
+ This module is often used to detect SMI (System Management
+ Interrupts) on x86 systems, though is not x86 specific. To
+ this end, we default to using a sample window of 1 second,
+ during which we will sample for 0.5 seconds. If an SMI or
+ similar event occurs during that time, it is recorded
+ into an 8K samples global ring buffer until retreived.
+
+ WARNING: This software should never be enabled (it can be built
+ but should not be turned on after it is loaded) in a production
+ environment where high latencies are a concern since the
+ sampling mechanism actually introduces latencies for
+ regular tasks while the CPU(s) are being held.
+
+ If unsure, say N
+
config PHANTOM
tristate "Sensable PHANToM (PCI)"
depends on PCI
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 20a9129..4f4e74b 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -54,3 +54,4 @@ obj-$(CONFIG_VMWARE_VMCI) += vmw_vmci/
obj-$(CONFIG_LATTICE_ECP3_CONFIG) += lattice-ecp3-config.o
obj-$(CONFIG_SRAM) += sram.o
obj-$(CONFIG_FSL_DCM) += fsl_dcm.o
+obj-$(CONFIG_HWLAT_DETECTOR) += hwlat_detector.o
diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c
new file mode 100644
index 0000000..2429c43
--- /dev/null
+++ b/drivers/misc/hwlat_detector.c
@@ -0,0 +1,1240 @@
+/*
+ * hwlat_detector.c - A simple Hardware Latency detector.
+ *
+ * Use this module to detect large system latencies induced by the behavior of
+ * certain underlying system hardware or firmware, independent of Linux itself.
+ * The code was developed originally to detect the presence of SMIs on Intel
+ * and AMD systems, although there is no dependency upon x86 herein.
+ *
+ * The classical example usage of this module is in detecting the presence of
+ * SMIs or System Management Interrupts on Intel and AMD systems. An SMI is a
+ * somewhat special form of hardware interrupt spawned from earlier CPU debug
+ * modes in which the (BIOS/EFI/etc.) firmware arranges for the South Bridge
+ * LPC (or other device) to generate a special interrupt under certain
+ * circumstances, for example, upon expiration of a special SMI timer device,
+ * due to certain external thermal readings, on certain I/O address accesses,
+ * and other situations. An SMI hits a special CPU pin, triggers a special
+ * SMI mode (complete with special memory map), and the OS is unaware.
+ *
+ * Although certain hardware-inducing latencies are necessary (for example,
+ * a modern system often requires an SMI handler for correct thermal control
+ * and remote management) they can wreak havoc upon any OS-level performance
+ * guarantees toward low-latency, especially when the OS is not even made
+ * aware of the presence of these interrupts. For this reason, we need a
+ * somewhat brute force mechanism to detect these interrupts. In this case,
+ * we do it by hogging all of the CPU(s) for configurable timer intervals,
+ * sampling the built-in CPU timer, looking for discontiguous readings.
+ *
+ * WARNING: This implementation necessarily introduces latencies. Therefore,
+ * you should NEVER use this module in a production environment
+ * requiring any kind of low-latency performance guarantee(s).
+ *
+ * Copyright (C) 2008-2009 Jon Masters, Red Hat, Inc. <jcm@redhat.com>
+ *
+ * Includes useful feedback from Clark Williams <clark@redhat.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/ring_buffer.h>
+#include <linux/time.h>
+#include <linux/hrtimer.h>
+#include <linux/kthread.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/version.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/trace_clock.h>
+
+#define BUF_SIZE_DEFAULT 262144UL /* 8K*(sizeof(entry)) */
+#define BUF_FLAGS (RB_FL_OVERWRITE) /* no block on full */
+#define U64STR_SIZE 22 /* 20 digits max */
+
+#define VERSION "1.0.0"
+#define BANNER "hwlat_detector: "
+#define DRVNAME "hwlat_detector"
+#define DEFAULT_SAMPLE_WINDOW 1000000 /* 1s */
+#define DEFAULT_SAMPLE_WIDTH 500000 /* 0.5s */
+#define DEFAULT_LAT_THRESHOLD 10 /* 10us */
+
+/* Module metadata */
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jon Masters <jcm@redhat.com>");
+MODULE_DESCRIPTION("A simple hardware latency detector");
+MODULE_VERSION(VERSION);
+
+/* Module parameters */
+
+static int debug;
+static int enabled;
+static int threshold;
+
+module_param(debug, int, 0); /* enable debug */
+module_param(enabled, int, 0); /* enable detector */
+module_param(threshold, int, 0); /* latency threshold */
+
+/* Buffering and sampling */
+
+static struct ring_buffer *ring_buffer; /* sample buffer */
+static DEFINE_MUTEX(ring_buffer_mutex); /* lock changes */
+static unsigned long buf_size = BUF_SIZE_DEFAULT;
+static struct task_struct *kthread; /* sampling thread */
+
+/* DebugFS filesystem entries */
+
+static struct dentry *debug_dir; /* debugfs directory */
+static struct dentry *debug_max; /* maximum TSC delta */
+static struct dentry *debug_count; /* total detect count */
+static struct dentry *debug_sample_width; /* sample width us */
+static struct dentry *debug_sample_window; /* sample window us */
+static struct dentry *debug_sample; /* raw samples us */
+static struct dentry *debug_threshold; /* threshold us */
+static struct dentry *debug_enable; /* enable/disable */
+
+/* Individual samples and global state */
+
+struct sample; /* latency sample */
+struct data; /* Global state */
+
+/* Sampling functions */
+static int __buffer_add_sample(struct sample *sample);
+static struct sample *buffer_get_sample(struct sample *sample);
+
+/* Threading and state */
+static int kthread_fn(void *unused);
+static int start_kthread(void);
+static int stop_kthread(void);
+static void __reset_stats(void);
+static int init_stats(void);
+
+/* Debugfs interface */
+static ssize_t simple_data_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos, const u64 *entry);
+static ssize_t simple_data_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos, u64 *entry);
+static int debug_sample_fopen(struct inode *inode, struct file *filp);
+static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos);
+static int debug_sample_release(struct inode *inode, struct file *filp);
+static int debug_enable_fopen(struct inode *inode, struct file *filp);
+static ssize_t debug_enable_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos);
+static ssize_t debug_enable_fwrite(struct file *file,
+ const char __user *user_buffer,
+ size_t user_size, loff_t *offset);
+
+/* Initialization functions */
+static int init_debugfs(void);
+static void free_debugfs(void);
+static int detector_init(void);
+static void detector_exit(void);
+
+/* Individual latency samples are stored here when detected and packed into
+ * the ring_buffer circular buffer, where they are overwritten when
+ * more than buf_size/sizeof(sample) samples are received. */
+struct sample {
+ u64 seqnum; /* unique sequence */
+ u64 duration; /* ktime delta */
+ u64 outer_duration; /* ktime delta (outer loop) */
+ struct timespec timestamp; /* wall time */
+ unsigned long lost;
+};
+
+/* keep the global state somewhere. */
+static struct data {
+
+ struct mutex lock; /* protect changes */
+
+ u64 count; /* total since reset */
+ u64 max_sample; /* max hardware latency */
+ u64 threshold; /* sample threshold level */
+
+ u64 sample_window; /* total sampling window (on+off) */
+ u64 sample_width; /* active sampling portion of window */
+
+ atomic_t sample_open; /* whether the sample file is open */
+
+ wait_queue_head_t wq; /* waitqeue for new sample values */
+
+} data;
+
+/**
+ * __buffer_add_sample - add a new latency sample recording to the ring buffer
+ * @sample: The new latency sample value
+ *
+ * This receives a new latency sample and records it in a global ring buffer.
+ * No additional locking is used in this case.
+ */
+static int __buffer_add_sample(struct sample *sample)
+{
+ return ring_buffer_write(ring_buffer,
+ sizeof(struct sample), sample);
+}
+
+/**
+ * buffer_get_sample - remove a hardware latency sample from the ring buffer
+ * @sample: Pre-allocated storage for the sample
+ *
+ * This retrieves a hardware latency sample from the global circular buffer
+ */
+static struct sample *buffer_get_sample(struct sample *sample)
+{
+ struct ring_buffer_event *e = NULL;
+ struct sample *s = NULL;
+ unsigned int cpu = 0;
+
+ if (!sample)
+ return NULL;
+
+ mutex_lock(&ring_buffer_mutex);
+ for_each_online_cpu(cpu) {
+ e = ring_buffer_consume(ring_buffer, cpu, NULL, &sample->lost);
+ if (e)
+ break;
+ }
+
+ if (e) {
+ s = ring_buffer_event_data(e);
+ memcpy(sample, s, sizeof(struct sample));
+ } else
+ sample = NULL;
+ mutex_unlock(&ring_buffer_mutex);
+
+ return sample;
+}
+
+#ifndef CONFIG_TRACING
+#define time_type ktime_t
+#define time_get() ktime_get()
+#define time_to_us(x) ktime_to_us(x)
+#define time_sub(a, b) ktime_sub(a, b)
+#define init_time(a, b) (a).tv64 = b
+#define time_u64(a) ((a).tv64)
+#else
+#define time_type u64
+#define time_get() trace_clock_local()
+#define time_to_us(x) div_u64(x, 1000)
+#define time_sub(a, b) ((a) - (b))
+#define init_time(a, b) (a = b)
+#define time_u64(a) a
+#endif
+/**
+ * get_sample - sample the CPU TSC and look for likely hardware latencies
+ *
+ * Used to repeatedly capture the CPU TSC (or similar), looking for potential
+ * hardware-induced latency. Called with interrupts disabled and with
+ * data.lock held.
+ */
+static int get_sample(void)
+{
+ time_type start, t1, t2, last_t2;
+ s64 diff, total = 0;
+ u64 sample = 0;
+ u64 outer_sample = 0;
+ int ret = -1;
+
+ init_time(last_t2, 0);
+ start = time_get(); /* start timestamp */
+
+ do {
+
+ t1 = time_get(); /* we'll look for a discontinuity */
+ t2 = time_get();
+
+ if (time_u64(last_t2)) {
+ /* Check the delta from outer loop (t2 to next t1) */
+ diff = time_to_us(time_sub(t1, last_t2));
+ /* This shouldn't happen */
+ if (diff < 0) {
+ pr_err(BANNER "time running backwards\n");
+ goto out;
+ }
+ if (diff > outer_sample)
+ outer_sample = diff;
+ }
+ last_t2 = t2;
+
+ total = time_to_us(time_sub(t2, start)); /* sample width */
+
+ /* This checks the inner loop (t1 to t2) */
+ diff = time_to_us(time_sub(t2, t1)); /* current diff */
+
+ /* This shouldn't happen */
+ if (diff < 0) {
+ pr_err(BANNER "time running backwards\n");
+ goto out;
+ }
+
+ if (diff > sample)
+ sample = diff; /* only want highest value */
+
+ } while (total <= data.sample_width);
+
+ ret = 0;
+
+ /* If we exceed the threshold value, we have found a hardware latency */
+ if (sample > data.threshold || outer_sample > data.threshold) {
+ struct sample s;
+
+ ret = 1;
+
+ data.count++;
+ s.seqnum = data.count;
+ s.duration = sample;
+ s.outer_duration = outer_sample;
+ s.timestamp = CURRENT_TIME;
+ __buffer_add_sample(&s);
+
+ /* Keep a running maximum ever recorded hardware latency */
+ if (sample > data.max_sample)
+ data.max_sample = sample;
+ }
+
+out:
+ return ret;
+}
+
+/*
+ * kthread_fn - The CPU time sampling/hardware latency detection kernel thread
+ * @unused: A required part of the kthread API.
+ *
+ * Used to periodically sample the CPU TSC via a call to get_sample. We
+ * disable interrupts, which does (intentionally) introduce latency since we
+ * need to ensure nothing else might be running (and thus pre-empting).
+ * Obviously this should never be used in production environments.
+ *
+ * Currently this runs on which ever CPU it was scheduled on, but most
+ * real-worald hardware latency situations occur across several CPUs,
+ * but we might later generalize this if we find there are any actualy
+ * systems with alternate SMI delivery or other hardware latencies.
+ */
+static int kthread_fn(void *unused)
+{
+ int ret;
+ u64 interval;
+
+ while (!kthread_should_stop()) {
+
+ mutex_lock(&data.lock);
+
+ local_irq_disable();
+ ret = get_sample();
+ local_irq_enable();
+
+ if (ret > 0)
+ wake_up(&data.wq); /* wake up reader(s) */
+
+ interval = data.sample_window - data.sample_width;
+ do_div(interval, USEC_PER_MSEC); /* modifies interval value */
+
+ mutex_unlock(&data.lock);
+
+ if (msleep_interruptible(interval))
+ break;
+ }
+
+ return 0;
+}
+
+/**
+ * start_kthread - Kick off the hardware latency sampling/detector kthread
+ *
+ * This starts a kernel thread that will sit and sample the CPU timestamp
+ * counter (TSC or similar) and look for potential hardware latencies.
+ */
+static int start_kthread(void)
+{
+ kthread = kthread_run(kthread_fn, NULL,
+ DRVNAME);
+ if (IS_ERR(kthread)) {
+ pr_err(BANNER "could not start sampling thread\n");
+ enabled = 0;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+/**
+ * stop_kthread - Inform the hardware latency samping/detector kthread to stop
+ *
+ * This kicks the running hardware latency sampling/detector kernel thread and
+ * tells it to stop sampling now. Use this on unload and at system shutdown.
+ */
+static int stop_kthread(void)
+{
+ int ret;
+
+ ret = kthread_stop(kthread);
+
+ return ret;
+}
+
+/**
+ * __reset_stats - Reset statistics for the hardware latency detector
+ *
+ * We use data to store various statistics and global state. We call this
+ * function in order to reset those when "enable" is toggled on or off, and
+ * also at initialization. Should be called with data.lock held.
+ */
+static void __reset_stats(void)
+{
+ data.count = 0;
+ data.max_sample = 0;
+ ring_buffer_reset(ring_buffer); /* flush out old sample entries */
+}
+
+/**
+ * init_stats - Setup global state statistics for the hardware latency detector
+ *
+ * We use data to store various statistics and global state. We also use
+ * a global ring buffer (ring_buffer) to keep raw samples of detected hardware
+ * induced system latencies. This function initializes these structures and
+ * allocates the global ring buffer also.
+ */
+static int init_stats(void)
+{
+ int ret = -ENOMEM;
+
+ mutex_init(&data.lock);
+ init_waitqueue_head(&data.wq);
+ atomic_set(&data.sample_open, 0);
+
+ ring_buffer = ring_buffer_alloc(buf_size, BUF_FLAGS);
+
+ if (WARN(!ring_buffer, KERN_ERR BANNER
+ "failed to allocate ring buffer!\n"))
+ goto out;
+
+ __reset_stats();
+ data.threshold = threshold ?: DEFAULT_LAT_THRESHOLD; /* threshold us */
+ data.sample_window = DEFAULT_SAMPLE_WINDOW; /* window us */
+ data.sample_width = DEFAULT_SAMPLE_WIDTH; /* width us */
+
+ ret = 0;
+
+out:
+ return ret;
+
+}
+
+/*
+ * simple_data_read - Wrapper read function for global state debugfs entries
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ * @entry: The entry to read from
+ *
+ * This function provides a generic read implementation for the global state
+ * "data" structure debugfs filesystem entries. It would be nice to use
+ * simple_attr_read directly, but we need to make sure that the data.lock
+ * is held during the actual read.
+ */
+static ssize_t simple_data_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos, const u64 *entry)
+{
+ char buf[U64STR_SIZE];
+ u64 val = 0;
+ int len = 0;
+
+ memset(buf, 0, sizeof(buf));
+
+ if (!entry)
+ return -EFAULT;
+
+ mutex_lock(&data.lock);
+ val = *entry;
+ mutex_unlock(&data.lock);
+
+ len = snprintf(buf, sizeof(buf), "%llu\n", (unsigned long long)val);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
+
+}
+
+/*
+ * simple_data_write - Wrapper write function for global state debugfs entries
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to write value from
+ * @cnt: The maximum number of bytes to write
+ * @ppos: The current "file" position
+ * @entry: The entry to write to
+ *
+ * This function provides a generic write implementation for the global state
+ * "data" structure debugfs filesystem entries. It would be nice to use
+ * simple_attr_write directly, but we need to make sure that the data.lock
+ * is held during the actual write.
+ */
+static ssize_t simple_data_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos, u64 *entry)
+{
+ char buf[U64STR_SIZE];
+ int csize = min(cnt, sizeof(buf));
+ u64 val = 0;
+ int err = 0;
+
+ memset(buf, '\0', sizeof(buf));
+ if (copy_from_user(buf, ubuf, csize))
+ return -EFAULT;
+
+ buf[U64STR_SIZE-1] = '\0'; /* just in case */
+ err = kstrtoull(buf, 10, &val);
+ if (err)
+ return -EINVAL;
+
+ mutex_lock(&data.lock);
+ *entry = val;
+ mutex_unlock(&data.lock);
+
+ return csize;
+}
+
+/**
+ * debug_count_fopen - Open function for "count" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "count" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_count_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_count_fread - Read function for "count" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "count" debugfs
+ * interface to the hardware latency detector. Can be used to read the
+ * number of latency readings exceeding the configured threshold since
+ * the detector was last reset (e.g. by writing a zero into "count").
+ */
+static ssize_t debug_count_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.count);
+}
+
+/**
+ * debug_count_fwrite - Write function for "count" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "count" debugfs
+ * interface to the hardware latency detector. Can be used to write a
+ * desired value, especially to zero the total count.
+ */
+static ssize_t debug_count_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ return simple_data_write(filp, ubuf, cnt, ppos, &data.count);
+}
+
+/**
+ * debug_enable_fopen - Dummy open function for "enable" debugfs interface
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "enable" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_enable_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_enable_fread - Read function for "enable" debugfs interface
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "enable" debugfs
+ * interface to the hardware latency detector. Can be used to determine
+ * whether the detector is currently enabled ("0\n" or "1\n" returned).
+ */
+static ssize_t debug_enable_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[4];
+
+ if ((cnt < sizeof(buf)) || (*ppos))
+ return 0;
+
+ buf[0] = enabled ? '1' : '0';
+ buf[1] = '\n';
+ buf[2] = '\0';
+ if (copy_to_user(ubuf, buf, strlen(buf)))
+ return -EFAULT;
+ return *ppos = strlen(buf);
+}
+
+/**
+ * debug_enable_fwrite - Write function for "enable" debugfs interface
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "enable" debugfs
+ * interface to the hardware latency detector. Can be used to enable or
+ * disable the detector, which will have the side-effect of possibly
+ * also resetting the global stats and kicking off the measuring
+ * kthread (on an enable) or the converse (upon a disable).
+ */
+static ssize_t debug_enable_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ char buf[4];
+ int csize = min(cnt, sizeof(buf));
+ long val = 0;
+ int err = 0;
+
+ memset(buf, '\0', sizeof(buf));
+ if (copy_from_user(buf, ubuf, csize))
+ return -EFAULT;
+
+ buf[sizeof(buf)-1] = '\0'; /* just in case */
+ err = kstrtoul(buf, 10, &val);
+ if (0 != err)
+ return -EINVAL;
+
+ if (val) {
+ if (enabled)
+ goto unlock;
+ enabled = 1;
+ __reset_stats();
+ if (start_kthread())
+ return -EFAULT;
+ } else {
+ if (!enabled)
+ goto unlock;
+ enabled = 0;
+ err = stop_kthread();
+ if (err) {
+ pr_err(BANNER "cannot stop kthread\n");
+ return -EFAULT;
+ }
+ wake_up(&data.wq); /* reader(s) should return */
+ }
+unlock:
+ return csize;
+}
+
+/**
+ * debug_max_fopen - Open function for "max" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "max" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_max_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_max_fread - Read function for "max" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "max" debugfs
+ * interface to the hardware latency detector. Can be used to determine
+ * the maximum latency value observed since it was last reset.
+ */
+static ssize_t debug_max_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.max_sample);
+}
+
+/**
+ * debug_max_fwrite - Write function for "max" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "max" debugfs
+ * interface to the hardware latency detector. Can be used to reset the
+ * maximum or set it to some other desired value - if, then, subsequent
+ * measurements exceed this value, the maximum will be updated.
+ */
+static ssize_t debug_max_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ return simple_data_write(filp, ubuf, cnt, ppos, &data.max_sample);
+}
+
+
+/**
+ * debug_sample_fopen - An open function for "sample" debugfs interface
+ * @inode: The in-kernel inode representation of this debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function handles opening the "sample" file within the hardware
+ * latency detector debugfs directory interface. This file is used to read
+ * raw samples from the global ring_buffer and allows the user to see a
+ * running latency history. Can be opened blocking or non-blocking,
+ * affecting whether it behaves as a buffer read pipe, or does not.
+ * Implements simple locking to prevent multiple simultaneous use.
+ */
+static int debug_sample_fopen(struct inode *inode, struct file *filp)
+{
+ if (!atomic_add_unless(&data.sample_open, 1, 1))
+ return -EBUSY;
+ else
+ return 0;
+}
+
+/**
+ * debug_sample_fread - A read function for "sample" debugfs interface
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that will contain the samples read
+ * @cnt: The maximum bytes to read from the debugfs "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function handles reading from the "sample" file within the hardware
+ * latency detector debugfs directory interface. This file is used to read
+ * raw samples from the global ring_buffer and allows the user to see a
+ * running latency history. By default this will block pending a new
+ * value written into the sample buffer, unless there are already a
+ * number of value(s) waiting in the buffer, or the sample file was
+ * previously opened in a non-blocking mode of operation.
+ */
+static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ int len = 0;
+ char buf[64];
+ struct sample *sample = NULL;
+
+ if (!enabled)
+ return 0;
+
+ sample = kzalloc(sizeof(struct sample), GFP_KERNEL);
+ if (!sample)
+ return -ENOMEM;
+
+ while (!buffer_get_sample(sample)) {
+
+ DEFINE_WAIT(wait);
+
+ if (filp->f_flags & O_NONBLOCK) {
+ len = -EAGAIN;
+ goto out;
+ }
+
+ prepare_to_wait(&data.wq, &wait, TASK_INTERRUPTIBLE);
+ schedule();
+ finish_wait(&data.wq, &wait);
+
+ if (signal_pending(current)) {
+ len = -EINTR;
+ goto out;
+ }
+
+ if (!enabled) { /* enable was toggled */
+ len = 0;
+ goto out;
+ }
+ }
+
+ len = snprintf(buf, sizeof(buf), "%010lu.%010lu\t%llu\t%llu\n",
+ sample->timestamp.tv_sec,
+ sample->timestamp.tv_nsec,
+ sample->duration,
+ sample->outer_duration);
+
+
+ /* handling partial reads is more trouble than it's worth */
+ if (len > cnt)
+ goto out;
+
+ if (copy_to_user(ubuf, buf, len))
+ len = -EFAULT;
+
+out:
+ kfree(sample);
+ return len;
+}
+
+/**
+ * debug_sample_release - Release function for "sample" debugfs interface
+ * @inode: The in-kernel inode represenation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function completes the close of the debugfs interface "sample" file.
+ * Frees the sample_open "lock" so that other users may open the interface.
+ */
+static int debug_sample_release(struct inode *inode, struct file *filp)
+{
+ atomic_dec(&data.sample_open);
+
+ return 0;
+}
+
+/**
+ * debug_threshold_fopen - Open function for "threshold" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "threshold" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_threshold_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_threshold_fread - Read function for "threshold" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "threshold" debugfs
+ * interface to the hardware latency detector. It can be used to determine
+ * the current threshold level at which a latency will be recorded in the
+ * global ring buffer, typically on the order of 10us.
+ */
+static ssize_t debug_threshold_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.threshold);
+}
+
+/**
+ * debug_threshold_fwrite - Write function for "threshold" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "threshold" debugfs
+ * interface to the hardware latency detector. It can be used to configure
+ * the threshold level at which any subsequently detected latencies will
+ * be recorded into the global ring buffer.
+ */
+static ssize_t debug_threshold_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ int ret;
+
+ ret = simple_data_write(filp, ubuf, cnt, ppos, &data.threshold);
+
+ if (enabled)
+ wake_up_process(kthread);
+
+ return ret;
+}
+
+/**
+ * debug_width_fopen - Open function for "width" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "width" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_width_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_width_fread - Read function for "width" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "width" debugfs
+ * interface to the hardware latency detector. It can be used to determine
+ * for how many us of the total window us we will actively sample for any
+ * hardware-induced latecy periods. Obviously, it is not possible to
+ * sample constantly and have the system respond to a sample reader, or,
+ * worse, without having the system appear to have gone out to lunch.
+ */
+static ssize_t debug_width_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.sample_width);
+}
+
+/**
+ * debug_width_fwrite - Write function for "width" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "width" debugfs
+ * interface to the hardware latency detector. It can be used to configure
+ * for how many us of the total window us we will actively sample for any
+ * hardware-induced latency periods. Obviously, it is not possible to
+ * sample constantly and have the system respond to a sample reader, or,
+ * worse, without having the system appear to have gone out to lunch. It
+ * is enforced that width is less that the total window size.
+ */
+static ssize_t debug_width_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ char buf[U64STR_SIZE];
+ int csize = min(cnt, sizeof(buf));
+ u64 val = 0;
+ int err = 0;
+
+ memset(buf, '\0', sizeof(buf));
+ if (copy_from_user(buf, ubuf, csize))
+ return -EFAULT;
+
+ buf[U64STR_SIZE-1] = '\0'; /* just in case */
+ err = kstrtoull(buf, 10, &val);
+ if (0 != err)
+ return -EINVAL;
+
+ mutex_lock(&data.lock);
+ if (val < data.sample_window)
+ data.sample_width = val;
+ else {
+ mutex_unlock(&data.lock);
+ return -EINVAL;
+ }
+ mutex_unlock(&data.lock);
+
+ if (enabled)
+ wake_up_process(kthread);
+
+ return csize;
+}
+
+/**
+ * debug_window_fopen - Open function for "window" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "window" debugfs
+ * interface to the hardware latency detector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs.
+ */
+static int debug_window_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_window_fread - Read function for "window" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "window" debugfs
+ * interface to the hardware latency detector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs. Can be used to read the total window size.
+ */
+static ssize_t debug_window_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.sample_window);
+}
+
+/**
+ * debug_window_fwrite - Write function for "window" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "window" debufds
+ * interface to the hardware latency detetector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs. Can be used to write a new total window size. It
+ * is enfoced that any value written must be greater than the sample width
+ * size, or an error results.
+ */
+static ssize_t debug_window_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ char buf[U64STR_SIZE];
+ int csize = min(cnt, sizeof(buf));
+ u64 val = 0;
+ int err = 0;
+
+ memset(buf, '\0', sizeof(buf));
+ if (copy_from_user(buf, ubuf, csize))
+ return -EFAULT;
+
+ buf[U64STR_SIZE-1] = '\0'; /* just in case */
+ err = kstrtoull(buf, 10, &val);
+ if (0 != err)
+ return -EINVAL;
+
+ mutex_lock(&data.lock);
+ if (data.sample_width < val)
+ data.sample_window = val;
+ else {
+ mutex_unlock(&data.lock);
+ return -EINVAL;
+ }
+ mutex_unlock(&data.lock);
+
+ return csize;
+}
+
+/*
+ * Function pointers for the "count" debugfs file operations
+ */
+static const struct file_operations count_fops = {
+ .open = debug_count_fopen,
+ .read = debug_count_fread,
+ .write = debug_count_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "enable" debugfs file operations
+ */
+static const struct file_operations enable_fops = {
+ .open = debug_enable_fopen,
+ .read = debug_enable_fread,
+ .write = debug_enable_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "max" debugfs file operations
+ */
+static const struct file_operations max_fops = {
+ .open = debug_max_fopen,
+ .read = debug_max_fread,
+ .write = debug_max_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "sample" debugfs file operations
+ */
+static const struct file_operations sample_fops = {
+ .open = debug_sample_fopen,
+ .read = debug_sample_fread,
+ .release = debug_sample_release,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "threshold" debugfs file operations
+ */
+static const struct file_operations threshold_fops = {
+ .open = debug_threshold_fopen,
+ .read = debug_threshold_fread,
+ .write = debug_threshold_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "width" debugfs file operations
+ */
+static const struct file_operations width_fops = {
+ .open = debug_width_fopen,
+ .read = debug_width_fread,
+ .write = debug_width_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "window" debugfs file operations
+ */
+static const struct file_operations window_fops = {
+ .open = debug_window_fopen,
+ .read = debug_window_fread,
+ .write = debug_window_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/**
+ * init_debugfs - A function to initialize the debugfs interface files
+ *
+ * This function creates entries in debugfs for "hwlat_detector", including
+ * files to read values from the detector, current samples, and the
+ * maximum sample that has been captured since the hardware latency
+ * dectector was started.
+ */
+static int init_debugfs(void)
+{
+ int ret = -ENOMEM;
+
+ debug_dir = debugfs_create_dir(DRVNAME, NULL);
+ if (!debug_dir)
+ goto err_debug_dir;
+
+ debug_sample = debugfs_create_file("sample", 0444,
+ debug_dir, NULL,
+ &sample_fops);
+ if (!debug_sample)
+ goto err_sample;
+
+ debug_count = debugfs_create_file("count", 0444,
+ debug_dir, NULL,
+ &count_fops);
+ if (!debug_count)
+ goto err_count;
+
+ debug_max = debugfs_create_file("max", 0444,
+ debug_dir, NULL,
+ &max_fops);
+ if (!debug_max)
+ goto err_max;
+
+ debug_sample_window = debugfs_create_file("window", 0644,
+ debug_dir, NULL,
+ &window_fops);
+ if (!debug_sample_window)
+ goto err_window;
+
+ debug_sample_width = debugfs_create_file("width", 0644,
+ debug_dir, NULL,
+ &width_fops);
+ if (!debug_sample_width)
+ goto err_width;
+
+ debug_threshold = debugfs_create_file("threshold", 0644,
+ debug_dir, NULL,
+ &threshold_fops);
+ if (!debug_threshold)
+ goto err_threshold;
+
+ debug_enable = debugfs_create_file("enable", 0644,
+ debug_dir, &enabled,
+ &enable_fops);
+ if (!debug_enable)
+ goto err_enable;
+
+ else {
+ ret = 0;
+ goto out;
+ }
+
+err_enable:
+ debugfs_remove(debug_threshold);
+err_threshold:
+ debugfs_remove(debug_sample_width);
+err_width:
+ debugfs_remove(debug_sample_window);
+err_window:
+ debugfs_remove(debug_max);
+err_max:
+ debugfs_remove(debug_count);
+err_count:
+ debugfs_remove(debug_sample);
+err_sample:
+ debugfs_remove(debug_dir);
+err_debug_dir:
+out:
+ return ret;
+}
+
+/**
+ * free_debugfs - A function to cleanup the debugfs file interface
+ */
+static void free_debugfs(void)
+{
+ /* could also use a debugfs_remove_recursive */
+ debugfs_remove(debug_enable);
+ debugfs_remove(debug_threshold);
+ debugfs_remove(debug_sample_width);
+ debugfs_remove(debug_sample_window);
+ debugfs_remove(debug_max);
+ debugfs_remove(debug_count);
+ debugfs_remove(debug_sample);
+ debugfs_remove(debug_dir);
+}
+
+/**
+ * detector_init - Standard module initialization code
+ */
+static int detector_init(void)
+{
+ int ret = -ENOMEM;
+
+ pr_info(BANNER "version %s\n", VERSION);
+
+ ret = init_stats();
+ if (0 != ret)
+ goto out;
+
+ ret = init_debugfs();
+ if (0 != ret)
+ goto err_stats;
+
+ if (enabled)
+ ret = start_kthread();
+
+ goto out;
+
+err_stats:
+ ring_buffer_free(ring_buffer);
+out:
+ return ret;
+
+}
+
+/**
+ * detector_exit - Standard module cleanup code
+ */
+static void detector_exit(void)
+{
+ int err;
+
+ if (enabled) {
+ enabled = 0;
+ err = stop_kthread();
+ if (err)
+ pr_err(BANNER "cannot stop kthread\n");
+ }
+
+ free_debugfs();
+ ring_buffer_free(ring_buffer); /* free up the ring buffer */
+
+}
+
+module_init(detector_init);
+module_exit(detector_exit);
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index c3785ed..a0f63c9 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1023,15 +1023,12 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
struct sg_mapping_iter *sg_miter = &host->sg_miter;
struct variant_data *variant = host->variant;
void __iomem *base = host->base;
- unsigned long flags;
u32 status;
status = readl(base + MMCISTATUS);
dev_dbg(mmc_dev(host->mmc), "irq1 (pio) %08x\n", status);
- local_irq_save(flags);
-
do {
unsigned int remain, len;
char *buffer;
@@ -1071,8 +1068,6 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
sg_miter_stop(sg_miter);
- local_irq_restore(flags);
-
/*
* If we have less than the fifo 'half-full' threshold to transfer,
* trigger a PIO interrupt as soon as any data is available.
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index dfe8a62..1989c90 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -302,6 +302,7 @@ config VXLAN
config NETCONSOLE
tristate "Network console logging support"
+ depends on !PREEMPT_RT_FULL
---help---
If you want to log kernel messages over the network, enable this.
See <file:Documentation/networking/netconsole.txt> for details.
diff --git a/drivers/net/ethernet/3com/3c59x.c b/drivers/net/ethernet/3com/3c59x.c
index ad5272b..55dd320 100644
--- a/drivers/net/ethernet/3com/3c59x.c
+++ b/drivers/net/ethernet/3com/3c59x.c
@@ -842,9 +842,9 @@ static void poll_vortex(struct net_device *dev)
{
struct vortex_private *vp = netdev_priv(dev);
unsigned long flags;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
(vp->full_bus_master_rx ? boomerang_interrupt:vortex_interrupt)(dev->irq,dev);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
#endif
@@ -1917,12 +1917,12 @@ static void vortex_tx_timeout(struct net_device *dev)
* Block interrupts because vortex_interrupt does a bare spin_lock()
*/
unsigned long flags;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (vp->full_bus_master_tx)
boomerang_interrupt(dev->irq, dev);
else
vortex_interrupt(dev->irq, dev);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
}
diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index a36a760..34ebd1b 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
@@ -2206,11 +2206,7 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff *skb,
}
tpd_req = atl1c_cal_tpd_req(skb);
- if (!spin_trylock_irqsave(&adapter->tx_lock, flags)) {
- if (netif_msg_pktdata(adapter))
- dev_info(&adapter->pdev->dev, "tx locked\n");
- return NETDEV_TX_LOCKED;
- }
+ spin_lock_irqsave(&adapter->tx_lock, flags);
if (atl1c_tpd_avail(adapter, type) < tpd_req) {
/* no enough descriptor, just stop queue */
diff --git a/drivers/net/ethernet/atheros/atl1e/atl1e_main.c b/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
index 1966444..d398960 100644
--- a/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
+++ b/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
@@ -1838,8 +1838,7 @@ static netdev_tx_t atl1e_xmit_frame(struct sk_buff *skb,
return NETDEV_TX_OK;
}
tpd_req = atl1e_cal_tdp_req(skb);
- if (!spin_trylock_irqsave(&adapter->tx_lock, flags))
- return NETDEV_TX_LOCKED;
+ spin_lock_irqsave(&adapter->tx_lock, flags);
if (atl1e_tpd_avail(adapter) < tpd_req) {
/* no enough descriptor, just stop queue */
diff --git a/drivers/net/ethernet/chelsio/cxgb/sge.c b/drivers/net/ethernet/chelsio/cxgb/sge.c
index 8061fb0..bfe5c72 100644
--- a/drivers/net/ethernet/chelsio/cxgb/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb/sge.c
@@ -1665,8 +1665,7 @@ static int t1_sge_tx(struct sk_buff *skb, struct adapter *adapter,
struct cmdQ *q = &sge->cmdQ[qid];
unsigned int credits, pidx, genbit, count, use_sched_skb = 0;
- if (!spin_trylock(&q->lock))
- return NETDEV_TX_LOCKED;
+ spin_lock(&q->lock);
reclaim_completed_tx(sge, q);
diff --git a/drivers/net/ethernet/dec/tulip/tulip_core.c b/drivers/net/ethernet/dec/tulip/tulip_core.c
index 4e8cfa2..7565b99 100644
--- a/drivers/net/ethernet/dec/tulip/tulip_core.c
+++ b/drivers/net/ethernet/dec/tulip/tulip_core.c
@@ -1939,6 +1939,7 @@ static void tulip_remove_one(struct pci_dev *pdev)
pci_iounmap(pdev, tp->base_addr);
free_netdev (dev);
pci_release_regions (pdev);
+ pci_disable_device(pdev);
pci_set_drvdata (pdev, NULL);
/* pci_power_off (pdev, -1); */
diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index d1c3799..8c6ae37 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -143,7 +143,6 @@ static int gfar_poll_tx(struct napi_struct *napi, int budget);
static void gfar_netpoll(struct net_device *dev);
#endif
int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue, int rx_work_limit);
-static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue);
static void gfar_process_frame(struct net_device *dev, struct sk_buff *skb,
int amount_pull, struct napi_struct *napi);
static void gfar_halt_nodisable(struct gfar_private *priv);
@@ -1467,7 +1466,7 @@ static int gfar_suspend(struct device *dev)
if (netif_running(ndev)) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
gfar_halt_nodisable(priv);
@@ -1483,7 +1482,7 @@ static int gfar_suspend(struct device *dev)
gfar_write(&regs->maccfg1, tempval);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
disable_napi(priv);
@@ -1525,7 +1524,7 @@ static int gfar_resume(struct device *dev)
/* Disable Magic Packet mode, in case something
* else woke us up.
*/
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
tempval = gfar_read(&regs->maccfg2);
@@ -1535,7 +1534,7 @@ static int gfar_resume(struct device *dev)
gfar_start(priv);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
netif_device_attach(ndev);
@@ -2444,7 +2443,7 @@ static void gfar_recycle_skb(struct sk_buff *skb)
}
/* Interrupt Handler for Transmit complete */
-static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
+static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
{
struct net_device *dev = tx_queue->dev;
struct netdev_queue *txq;
@@ -2976,8 +2975,11 @@ static int gfar_poll_tx(struct napi_struct *napi, int budget)
tx_queue = priv->tx_queue[i];
/* run Tx cleanup to completion */
if (tx_queue->tx_skbuff[tx_queue->skb_dirtytx]) {
- gfar_clean_tx_ring(tx_queue);
- has_tx_work = 1;
+ int ret;
+
+ ret = gfar_clean_tx_ring(tx_queue);
+ if (ret)
+ has_tx_work = 1;
}
}
diff --git a/drivers/net/ethernet/neterion/s2io.c b/drivers/net/ethernet/neterion/s2io.c
index 51b0094..809d92c 100644
--- a/drivers/net/ethernet/neterion/s2io.c
+++ b/drivers/net/ethernet/neterion/s2io.c
@@ -4089,12 +4089,7 @@ static netdev_tx_t s2io_xmit(struct sk_buff *skb, struct net_device *dev)
[skb->priority & (MAX_TX_FIFOS - 1)];
fifo = &mac_control->fifos[queue];
- if (do_spin_lock)
- spin_lock_irqsave(&fifo->tx_lock, flags);
- else {
- if (unlikely(!spin_trylock_irqsave(&fifo->tx_lock, flags)))
- return NETDEV_TX_LOCKED;
- }
+ spin_lock_irqsave(&fifo->tx_lock, flags);
if (sp->config.multiq) {
if (__netif_subqueue_stopped(dev, fifo->fifo_no)) {
diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
index 5a0f04c..e732812 100644
--- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
+++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
@@ -2148,10 +2148,8 @@ static int pch_gbe_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
struct pch_gbe_tx_ring *tx_ring = adapter->tx_ring;
unsigned long flags;
- if (!spin_trylock_irqsave(&tx_ring->tx_lock, flags)) {
- /* Collision - tell upper layer to requeue */
- return NETDEV_TX_LOCKED;
- }
+ spin_lock_irqsave(&tx_ring->tx_lock, flags);
+
if (unlikely(!PCH_GBE_DESC_UNUSED(tx_ring))) {
netif_stop_queue(netdev);
spin_unlock_irqrestore(&tx_ring->tx_lock, flags);
diff --git a/drivers/net/ethernet/realtek/8139too.c b/drivers/net/ethernet/realtek/8139too.c
index 3ccedeb..fefe07b 100644
--- a/drivers/net/ethernet/realtek/8139too.c
+++ b/drivers/net/ethernet/realtek/8139too.c
@@ -2213,7 +2213,7 @@ static void rtl8139_poll_controller(struct net_device *dev)
struct rtl8139_private *tp = netdev_priv(dev);
const int irq = tp->pci_dev->irq;
- disable_irq(irq);
+ disable_irq_nosync(irq);
rtl8139_interrupt(irq, dev);
enable_irq(irq);
}
diff --git a/drivers/net/ethernet/tehuti/tehuti.c b/drivers/net/ethernet/tehuti/tehuti.c
index 61a1540..7edf580 100644
--- a/drivers/net/ethernet/tehuti/tehuti.c
+++ b/drivers/net/ethernet/tehuti/tehuti.c
@@ -1629,13 +1629,8 @@ static netdev_tx_t bdx_tx_transmit(struct sk_buff *skb,
unsigned long flags;
ENTER;
- local_irq_save(flags);
- if (!spin_trylock(&priv->tx_lock)) {
- local_irq_restore(flags);
- DBG("%s[%s]: TX locked, returning NETDEV_TX_LOCKED\n",
- BDX_DRV_NAME, ndev->name);
- return NETDEV_TX_LOCKED;
- }
+
+ spin_lock_irqsave(&priv->tx_lock, flags);
/* build tx descriptor */
BDX_ASSERT(f->m.wptr >= f->m.memsz); /* started with valid wptr */
diff --git a/drivers/net/rionet.c b/drivers/net/rionet.c
index 6d1f6ed..aa9800e 100644
--- a/drivers/net/rionet.c
+++ b/drivers/net/rionet.c
@@ -174,11 +174,7 @@ static int rionet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
unsigned long flags;
int add_num = 1;
- local_irq_save(flags);
- if (!spin_trylock(&rnet->tx_lock)) {
- local_irq_restore(flags);
- return NETDEV_TX_LOCKED;
- }
+ spin_lock_irqsave(&rnet->tx_lock, flags);
if (is_multicast_ether_addr(eth->h_dest))
add_num = nets[rnet->mport->id].nact;
diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 7bdaf06..62aac3b 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -1394,6 +1394,20 @@ static const struct iwl_trans_ops trans_ops_pcie = {
.set_bits_mask = iwl_trans_pcie_set_bits_mask,
};
+#ifdef CONFIG_PREEMPT_RT_BASE
+static irqreturn_t iwl_rt_irq_handler(int irq, void *dev_id)
+{
+ irqreturn_t ret;
+
+ local_bh_disable();
+ ret = iwl_pcie_isr_ict(irq, dev_id);
+ local_bh_enable();
+ if (ret == IRQ_WAKE_THREAD)
+ ret = iwl_pcie_irq_handler(irq, dev_id);
+ return ret;
+}
+#endif
+
struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
const struct pci_device_id *ent,
const struct iwl_cfg *cfg)
@@ -1512,9 +1526,14 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
if (iwl_pcie_alloc_ict(trans))
goto out_free_cmd_pool;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ err = request_threaded_irq(pdev->irq, NULL, iwl_rt_irq_handler,
+ IRQF_SHARED | IRQF_ONESHOT, DRV_NAME, trans);
+#else
err = request_threaded_irq(pdev->irq, iwl_pcie_isr_ict,
iwl_pcie_irq_handler,
IRQF_SHARED, DRV_NAME, trans);
+#endif
if (err) {
IWL_ERR(trans, "Error allocating IRQ %d\n", pdev->irq);
goto out_free_ict;
diff --git a/drivers/net/wireless/orinoco/orinoco_usb.c b/drivers/net/wireless/orinoco/orinoco_usb.c
index bdfe637..0fbb1ce 100644
--- a/drivers/net/wireless/orinoco/orinoco_usb.c
+++ b/drivers/net/wireless/orinoco/orinoco_usb.c
@@ -714,7 +714,7 @@ static void ezusb_req_ctx_wait(struct ezusb_priv *upriv,
while (!ctx->done.done && msecs--)
udelay(1000);
} else {
- wait_event_interruptible(ctx->done.wait,
+ swait_event_interruptible(ctx->done.wait,
ctx->done.done);
}
break;
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 0857ca9..8bb624e 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -465,7 +465,7 @@ void pci_cfg_access_unlock(struct pci_dev *dev)
WARN_ON(!dev->block_cfg_access);
dev->block_cfg_access = 0;
- wake_up_all(&pci_cfg_wait);
+ wake_up_all_locked(&pci_cfg_wait);
raw_spin_unlock_irqrestore(&pci_lock, flags);
}
EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 07453bb..b439c20 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -1285,7 +1285,7 @@ static void fcoe_percpu_thread_destroy(unsigned int cpu)
struct sk_buff *skb;
#ifdef CONFIG_SMP
struct fcoe_percpu_s *p0;
- unsigned targ_cpu = get_cpu();
+ unsigned targ_cpu = get_cpu_light();
#endif /* CONFIG_SMP */
FCOE_DBG("Destroying receive thread for CPU %d\n", cpu);
@@ -1341,7 +1341,7 @@ static void fcoe_percpu_thread_destroy(unsigned int cpu)
kfree_skb(skb);
spin_unlock_bh(&p->fcoe_rx_list.lock);
}
- put_cpu();
+ put_cpu_light();
#else
/*
* This a non-SMP scenario where the singular Rx thread is
@@ -1559,11 +1559,11 @@ err2:
static int fcoe_alloc_paged_crc_eof(struct sk_buff *skb, int tlen)
{
struct fcoe_percpu_s *fps;
- int rc;
+ int rc, cpu = get_cpu_light();
- fps = &get_cpu_var(fcoe_percpu);
+ fps = &per_cpu(fcoe_percpu, cpu);
rc = fcoe_get_paged_crc_eof(skb, tlen, fps);
- put_cpu_var(fcoe_percpu);
+ put_cpu_light();
return rc;
}
@@ -1761,11 +1761,11 @@ static inline int fcoe_filter_frames(struct fc_lport *lport,
return 0;
}
- stats = per_cpu_ptr(lport->stats, get_cpu());
+ stats = per_cpu_ptr(lport->stats, get_cpu_light());
stats->InvalidCRCCount++;
if (stats->InvalidCRCCount < 5)
printk(KERN_WARNING "fcoe: dropping frame with CRC error\n");
- put_cpu();
+ put_cpu_light();
return -EINVAL;
}
@@ -1841,13 +1841,13 @@ static void fcoe_recv_frame(struct sk_buff *skb)
goto drop;
if (!fcoe_filter_frames(lport, fp)) {
- put_cpu();
+ put_cpu_light();
fc_exch_recv(lport, fp);
return;
}
drop:
stats->ErrorFrames++;
- put_cpu();
+ put_cpu_light();
kfree_skb(skb);
}
diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c
index 203415e..48769c3 100644
--- a/drivers/scsi/fcoe/fcoe_ctlr.c
+++ b/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -792,7 +792,7 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
INIT_LIST_HEAD(&del_list);
- stats = per_cpu_ptr(fip->lp->stats, get_cpu());
+ stats = per_cpu_ptr(fip->lp->stats, get_cpu_light());
list_for_each_entry_safe(fcf, next, &fip->fcfs, list) {
deadline = fcf->time + fcf->fka_period + fcf->fka_period / 2;
@@ -828,7 +828,7 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
sel_time = fcf->time;
}
}
- put_cpu();
+ put_cpu_light();
list_for_each_entry_safe(fcf, next, &del_list, list) {
/* Removes fcf from current list */
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 5879929..74c7eb0 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -741,10 +741,10 @@ static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
}
memset(ep, 0, sizeof(*ep));
- cpu = get_cpu();
+ cpu = get_cpu_light();
pool = per_cpu_ptr(mp->pool, cpu);
spin_lock_bh(&pool->lock);
- put_cpu();
+ put_cpu_light();
/* peek cache of free slot */
if (pool->left != FC_XID_UNKNOWN) {
diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h
index 957088b..f8213e1 100644
--- a/drivers/scsi/qla2xxx/qla_inline.h
+++ b/drivers/scsi/qla2xxx/qla_inline.h
@@ -58,12 +58,12 @@ qla2x00_poll(struct rsp_que *rsp)
{
unsigned long flags;
struct qla_hw_data *ha = rsp->hw;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (IS_P3P_TYPE(ha))
qla82xx_poll(0, rsp);
else
ha->isp_ops->intr_handler(0, rsp);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
static inline uint8_t *
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index f644226..312a83f 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -38,6 +38,7 @@
#include <linux/nmi.h>
#include <linux/mutex.h>
#include <linux/slab.h>
+#include <linux/kdb.h>
#ifdef CONFIG_SPARC
#include <linux/sunserialcore.h>
#endif
@@ -80,7 +81,16 @@ static unsigned int skip_txen_test; /* force skip of txen test at init time */
#define DEBUG_INTR(fmt...) do { } while (0)
#endif
-#define PASS_LIMIT 512
+/*
+ * On -rt we can have a more delays, and legitimately
+ * so - so don't drop work spuriously and spam the
+ * syslog:
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define PASS_LIMIT 1000000
+#else
+# define PASS_LIMIT 512
+#endif
#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
@@ -2882,14 +2892,10 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
touch_nmi_watchdog();
- local_irq_save(flags);
- if (port->sysrq) {
- /* serial8250_handle_irq() already took the lock */
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&port->lock);
- } else
- spin_lock(&port->lock);
+ if (port->sysrq || oops_in_progress || in_kdb_printk())
+ locked = spin_trylock_irqsave(&port->lock, flags);
+ else
+ spin_lock_irqsave(&port->lock, flags);
/*
* First save the IER then disable the interrupts
@@ -2921,8 +2927,7 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
serial8250_modem_status(up);
if (locked)
- spin_unlock(&port->lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static int __init serial8250_console_setup(struct console *co, char *options)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 1440d0b..729198c 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1916,13 +1916,19 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
clk_enable(uap->clk);
- local_irq_save(flags);
+ /*
+ * local_irq_save(flags);
+ *
+ * This local_irq_save() is nonsense. If we come in via sysrq
+ * handling then interrupts are already disabled. Aside of
+ * that the port.sysrq check is racy on SMP regardless.
+ */
if (uap->port.sysrq)
locked = 0;
else if (oops_in_progress)
- locked = spin_trylock(&uap->port.lock);
+ locked = spin_trylock_irqsave(&uap->port.lock, flags);
else
- spin_lock(&uap->port.lock);
+ spin_lock_irqsave(&uap->port.lock, flags);
/*
* First save the CR then disable the interrupts
@@ -1944,8 +1950,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
writew(old_cr, uap->port.membase + UART011_CR);
if (locked)
- spin_unlock(&uap->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&uap->port.lock, flags);
clk_disable(uap->clk);
}
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 816d1a2..22c8149 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1232,13 +1232,10 @@ serial_omap_console_write(struct console *co, const char *s,
pm_runtime_get_sync(up->dev);
- local_irq_save(flags);
- if (up->port.sysrq)
- locked = 0;
- else if (oops_in_progress)
- locked = spin_trylock(&up->port.lock);
+ if (up->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
else
- spin_lock(&up->port.lock);
+ spin_lock_irqsave(&up->port.lock, flags);
/*
* First save the IER then disable the interrupts
@@ -1267,8 +1264,7 @@ serial_omap_console_write(struct console *co, const char *s,
pm_runtime_mark_last_busy(up->dev);
pm_runtime_put_autosuspend(up->dev);
if (locked)
- spin_unlock(&up->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
static int __init
diff --git a/drivers/tty/serial/sunhv.c b/drivers/tty/serial/sunhv.c
index cf86e72..dc697ce 100644
--- a/drivers/tty/serial/sunhv.c
+++ b/drivers/tty/serial/sunhv.c
@@ -433,13 +433,10 @@ static void sunhv_console_write_paged(struct console *con, const char *s, unsign
unsigned long flags;
int locked = 1;
- local_irq_save(flags);
- if (port->sysrq) {
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&port->lock);
- } else
- spin_lock(&port->lock);
+ if (port->sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&port->lock, flags);
+ else
+ spin_lock_irqsave(&port->lock, flags);
while (n > 0) {
unsigned long ra = __pa(con_write_page);
@@ -470,8 +467,7 @@ static void sunhv_console_write_paged(struct console *con, const char *s, unsign
}
if (locked)
- spin_unlock(&port->lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static inline void sunhv_console_putchar(struct uart_port *port, char c)
@@ -492,7 +488,10 @@ static void sunhv_console_write_bychar(struct console *con, const char *s, unsig
unsigned long flags;
int i, locked = 1;
- local_irq_save(flags);
+ if (port->sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&port->lock, flags);
+ else
+ spin_lock_irqsave(&port->lock, flags);
if (port->sysrq) {
locked = 0;
} else if (oops_in_progress) {
@@ -507,8 +506,7 @@ static void sunhv_console_write_bychar(struct console *con, const char *s, unsig
}
if (locked)
- spin_unlock(&port->lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static struct console sunhv_console = {
diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
index 5d6136b..1bf2774 100644
--- a/drivers/tty/serial/sunsab.c
+++ b/drivers/tty/serial/sunsab.c
@@ -844,20 +844,16 @@ static void sunsab_console_write(struct console *con, const char *s, unsigned n)
unsigned long flags;
int locked = 1;
- local_irq_save(flags);
- if (up->port.sysrq) {
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&up->port.lock);
- } else
- spin_lock(&up->port.lock);
+ if (up->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
+ else
+ spin_lock_irqsave(&up->port.lock, flags);
uart_console_write(&up->port, s, n, sunsab_console_putchar);
sunsab_tec_wait(up);
if (locked)
- spin_unlock(&up->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
static int sunsab_console_setup(struct console *con, char *options)
diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index 699cc1b..d88fb63 100644
--- a/drivers/tty/serial/sunsu.c
+++ b/drivers/tty/serial/sunsu.c
@@ -1295,13 +1295,10 @@ static void sunsu_console_write(struct console *co, const char *s,
unsigned int ier;
int locked = 1;
- local_irq_save(flags);
- if (up->port.sysrq) {
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&up->port.lock);
- } else
- spin_lock(&up->port.lock);
+ if (up->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
+ else
+ spin_lock_irqsave(&up->port.lock, flags);
/*
* First save the UER then disable the interrupts
@@ -1319,8 +1316,7 @@ static void sunsu_console_write(struct console *co, const char *s,
serial_out(up, UART_IER, ier);
if (locked)
- spin_unlock(&up->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
/*
diff --git a/drivers/tty/serial/sunzilog.c b/drivers/tty/serial/sunzilog.c
index 135a152..3103c3b 100644
--- a/drivers/tty/serial/sunzilog.c
+++ b/drivers/tty/serial/sunzilog.c
@@ -1195,20 +1195,16 @@ sunzilog_console_write(struct console *con, const char *s, unsigned int count)
unsigned long flags;
int locked = 1;
- local_irq_save(flags);
- if (up->port.sysrq) {
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&up->port.lock);
- } else
- spin_lock(&up->port.lock);
+ if (up->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
+ else
+ spin_lock_irqsave(&up->port.lock, flags);
uart_console_write(&up->port, s, count, sunzilog_putchar);
udelay(2);
if (locked)
- spin_unlock(&up->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
static int __init sunzilog_console_setup(struct console *con, char *options)
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index c043136f..8a3b2a0 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -509,10 +509,14 @@ void tty_flip_buffer_push(struct tty_port *port)
buf->tail->commit = buf->tail->used;
+#ifndef CONFIG_PREEMPT_RT_FULL
if (port->low_latency)
flush_to_ldisc(&buf->work);
else
schedule_work(&buf->work);
+#else
+ schedule_work(&buf->work);
+#endif
}
EXPORT_SYMBOL(tty_flip_buffer_push);
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index d6a8d23..bf21a21 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1677,9 +1677,9 @@ static void __usb_hcd_giveback_urb(struct urb *urb)
* and no one may trigger the above deadlock situation when
* running complete() in tasklet.
*/
- local_irq_save(flags);
+ local_irq_save_nort(flags);
urb->complete(urb);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
atomic_dec(&urb->use_count);
if (unlikely(atomic_read(&urb->reject)))
@@ -2331,7 +2331,7 @@ irqreturn_t usb_hcd_irq (int irq, void *__hcd)
* when the first handler doesn't use it. So let's just
* assume it's never used.
*/
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
rc = IRQ_NONE;
@@ -2340,7 +2340,7 @@ irqreturn_t usb_hcd_irq (int irq, void *__hcd)
else
rc = IRQ_HANDLED;
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return rc;
}
EXPORT_SYMBOL_GPL(usb_hcd_irq);
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 44cf775..fd2fe19 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -1282,7 +1282,7 @@ static void ffs_data_put(struct ffs_data *ffs)
pr_info("%s(): freeing\n", __func__);
ffs_data_clear(ffs);
BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
- waitqueue_active(&ffs->ep0req_completion.wait));
+ swaitqueue_active(&ffs->ep0req_completion.wait));
kfree(ffs->dev_name);
kfree(ffs);
}
diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index b94c049..1033ecc 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -340,7 +340,7 @@ ep_io (struct ep_data *epdata, void *buf, unsigned len)
spin_unlock_irq (&epdata->dev->lock);
if (likely (value == 0)) {
- value = wait_event_interruptible (done.wait, done.done);
+ value = swait_event_interruptible (done.wait, done.done);
if (value != 0) {
spin_lock_irq (&epdata->dev->lock);
if (likely (epdata->ep != NULL)) {
@@ -349,7 +349,7 @@ ep_io (struct ep_data *epdata, void *buf, unsigned len)
usb_ep_dequeue (epdata->ep, epdata->req);
spin_unlock_irq (&epdata->dev->lock);
- wait_event (done.wait, done.done);
+ swait_event (done.wait, done.done);
if (epdata->status == -ECONNRESET)
epdata->status = -EINTR;
} else {
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 604cad1..b691278 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -874,9 +874,13 @@ static irqreturn_t ohci_irq (struct usb_hcd *hcd)
}
if (ints & OHCI_INTR_WDH) {
- spin_lock (&ohci->lock);
- dl_done_list (ohci);
- spin_unlock (&ohci->lock);
+ if (ohci->hcca->done_head == 0) {
+ ints &= ~OHCI_INTR_WDH;
+ } else {
+ spin_lock (&ohci->lock);
+ dl_done_list (ohci);
+ spin_unlock (&ohci->lock);
+ }
}
if (quirk_zfmicro(ohci) && (ints & OHCI_INTR_SF)) {
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index 3f1128b..c2ed9c4 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -34,6 +34,7 @@
#include <linux/sched.h>
#include <linux/mount.h>
#include <linux/namei.h>
+#include <linux/delay.h>
#include <asm/current.h>
#include <asm/uaccess.h>
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 3d9d3f5..b422ad6 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -157,7 +157,7 @@ again:
parent = p->d_parent;
if (!spin_trylock(&parent->d_lock)) {
spin_unlock(&p->d_lock);
- cpu_relax();
+ cpu_chill();
goto relock;
}
spin_unlock(&p->d_lock);
diff --git a/fs/buffer.c b/fs/buffer.c
index aeeea65..e0fa2a4 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -322,8 +322,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
* decide that the page is now completely done.
*/
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ flags = bh_uptodate_lock_irqsave(first);
clear_buffer_async_read(bh);
unlock_buffer(bh);
tmp = bh;
@@ -336,8 +335,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
}
tmp = tmp->b_this_page;
} while (tmp != bh);
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(first, flags);
/*
* If none of the buffers had errors and they are all
@@ -349,9 +347,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
return;
still_busy:
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
- return;
+ bh_uptodate_unlock_irqrestore(first, flags);
}
/*
@@ -385,8 +381,7 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate)
}
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ flags = bh_uptodate_lock_irqsave(first);
clear_buffer_async_write(bh);
unlock_buffer(bh);
@@ -398,15 +393,12 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate)
}
tmp = tmp->b_this_page;
}
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(first, flags);
end_page_writeback(page);
return;
still_busy:
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
- return;
+ bh_uptodate_unlock_irqrestore(first, flags);
}
EXPORT_SYMBOL(end_buffer_async_write);
@@ -3336,6 +3328,7 @@ struct buffer_head *alloc_buffer_head(gfp_t gfp_flags)
struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags);
if (ret) {
INIT_LIST_HEAD(&ret->b_assoc_buffers);
+ buffer_head_init_locks(ret);
preempt_disable();
__this_cpu_inc(bh_accounting.nr);
recalc_bh_state();
diff --git a/fs/dcache.c b/fs/dcache.c
index 30b38e2..6e84d2ab 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -19,6 +19,7 @@
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/fsnotify.h>
+#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/hash.h>
@@ -554,7 +555,7 @@ dentry_kill(struct dentry *dentry, int unlock_on_failure)
relock:
if (unlock_on_failure) {
spin_unlock(&dentry->d_lock);
- cpu_relax();
+ cpu_chill();
}
return dentry; /* try again with same dentry */
}
@@ -2391,7 +2392,7 @@ again:
if (dentry->d_lockref.count == 1) {
if (!spin_trylock(&inode->i_lock)) {
spin_unlock(&dentry->d_lock);
- cpu_relax();
+ cpu_chill();
goto again;
}
dentry->d_flags &= ~DCACHE_CANT_MOUNT;
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index d76c974..9691a6e 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -505,12 +505,12 @@ static int ep_poll_wakeup_proc(void *priv, void *cookie, int call_nests)
*/
static void ep_poll_safewake(wait_queue_head_t *wq)
{
- int this_cpu = get_cpu();
+ int this_cpu = get_cpu_light();
ep_call_nested(&poll_safewake_ncalls, EP_MAX_NESTS,
ep_poll_wakeup_proc, NULL, wq, (void *) (long) this_cpu);
- put_cpu();
+ put_cpu_light();
}
static void ep_remove_wait_queue(struct eppoll_entry *pwq)
diff --git a/fs/exec.c b/fs/exec.c
index bb8afc1..eb02518 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -840,10 +840,12 @@ static int exec_mmap(struct mm_struct *mm)
}
}
task_lock(tsk);
+ preempt_disable_rt();
active_mm = tsk->active_mm;
tsk->mm = mm;
tsk->active_mm = mm;
activate_mm(active_mm, mm);
+ preempt_enable_rt();
task_unlock(tsk);
arch_pick_mmap_layout(mm);
if (old_mm) {
diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c
index 08c0304..95debd7 100644
--- a/fs/jbd/checkpoint.c
+++ b/fs/jbd/checkpoint.c
@@ -129,6 +129,8 @@ void __log_wait_for_space(journal_t *journal)
if (journal->j_flags & JFS_ABORT)
return;
spin_unlock(&journal->j_state_lock);
+ if (current->plug)
+ io_schedule();
mutex_lock(&journal->j_checkpoint_mutex);
/*
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 7f34f47..8c40400 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -125,6 +125,8 @@ void __jbd2_log_wait_for_space(journal_t *journal)
if (journal->j_flags & JBD2_ABORT)
return;
write_unlock(&journal->j_state_lock);
+ if (current->plug)
+ io_schedule();
mutex_lock(&journal->j_checkpoint_mutex);
/*
diff --git a/fs/namespace.c b/fs/namespace.c
index 84447db..22cbfab 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -23,6 +23,7 @@
#include <linux/uaccess.h>
#include <linux/proc_ns.h>
#include <linux/magic.h>
+#include <linux/delay.h>
#include "pnode.h"
#include "internal.h"
@@ -315,8 +316,11 @@ int __mnt_want_write(struct vfsmount *m)
* incremented count after it has set MNT_WRITE_HOLD.
*/
smp_mb();
- while (ACCESS_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD)
- cpu_relax();
+ while (ACCESS_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) {
+ preempt_enable();
+ cpu_chill();
+ preempt_disable();
+ }
/*
* After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will
* be set to match its requirements. So we must not load that until
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index d267ea6..33f0d86 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -108,8 +108,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
"0x%llx.", (unsigned long long)bh->b_blocknr);
}
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ flags = bh_uptodate_lock_irqsave(first);
clear_buffer_async_read(bh);
unlock_buffer(bh);
tmp = bh;
@@ -124,8 +123,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
}
tmp = tmp->b_this_page;
} while (tmp != bh);
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(first, flags);
/*
* If none of the buffers had errors then we can set the page uptodate,
* but we first have to perform the post read mst fixups, if the
@@ -146,13 +144,13 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
recs = PAGE_CACHE_SIZE / rec_size;
/* Should have been verified before we got here... */
BUG_ON(!recs);
- local_irq_save(flags);
+ local_irq_save_nort(flags);
kaddr = kmap_atomic(page);
for (i = 0; i < recs; i++)
post_read_mst_fixup((NTFS_RECORD*)(kaddr +
i * rec_size), rec_size);
kunmap_atomic(kaddr);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
flush_dcache_page(page);
if (likely(page_uptodate && !PageError(page)))
SetPageUptodate(page);
@@ -160,9 +158,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
unlock_page(page);
return;
still_busy:
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
- return;
+ bh_uptodate_unlock_irqrestore(first, flags);
}
/**
diff --git a/fs/timerfd.c b/fs/timerfd.c
index 9293121..d20e45a 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -380,7 +380,10 @@ static int do_timerfd_settime(int ufd, int flags,
break;
}
spin_unlock_irq(&ctx->wqh.lock);
- cpu_relax();
+ if (isalarm(ctx))
+ hrtimer_wait_for_timer(&ctx->t.alarm.timer);
+ else
+ hrtimer_wait_for_timer(&ctx->t.tmr);
}
/*
diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index 68534ef..0ef299d 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h
@@ -72,6 +72,7 @@
#define acpi_cache_t struct kmem_cache
#define acpi_spinlock spinlock_t *
+#define acpi_raw_spinlock raw_spinlock_t *
#define acpi_cpu_flags unsigned long
#else /* !__KERNEL__ */
@@ -174,6 +175,19 @@ static inline void *acpi_os_acquire_object(acpi_cache_t * cache)
lock ? AE_OK : AE_NO_MEMORY; \
})
+#define acpi_os_create_raw_lock(__handle) \
+({ \
+ raw_spinlock_t *lock = ACPI_ALLOCATE(sizeof(*lock)); \
+ \
+ if (lock) { \
+ *(__handle) = lock; \
+ raw_spin_lock_init(*(__handle)); \
+ } \
+ lock ? AE_OK : AE_NO_MEMORY; \
+})
+
+#define acpi_os_delete_raw_lock(__handle) kfree(__handle)
+
#endif /* __KERNEL__ */
#endif /* __ACLINUX_H__ */
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 7d10f96..aee7fd2 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -202,6 +202,20 @@ extern void warn_slowpath_null(const char *file, const int line);
# define WARN_ON_SMP(x) ({0;})
#endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define BUG_ON_RT(c) BUG_ON(c)
+# define BUG_ON_NONRT(c) do { } while (0)
+# define WARN_ON_RT(condition) WARN_ON(condition)
+# define WARN_ON_NONRT(condition) do { } while (0)
+# define WARN_ON_ONCE_NONRT(condition) do { } while (0)
+#else
+# define BUG_ON_RT(c) do { } while (0)
+# define BUG_ON_NONRT(c) BUG_ON(c)
+# define WARN_ON_RT(condition) do { } while (0)
+# define WARN_ON_NONRT(condition) WARN_ON(condition)
+# define WARN_ON_ONCE_NONRT(condition) WARN_ON_ONCE(condition)
+#endif
+
#endif /* __ASSEMBLY__ */
#endif
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index d77797a..cac4973 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -75,8 +75,52 @@ struct buffer_head {
struct address_space *b_assoc_map; /* mapping this buffer is
associated with */
atomic_t b_count; /* users using this buffer_head */
+#ifdef CONFIG_PREEMPT_RT_BASE
+ spinlock_t b_uptodate_lock;
+#if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || \
+ defined(CONFIG_JBD2) || defined(CONFIG_JBD2_MODULE)
+ spinlock_t b_state_lock;
+ spinlock_t b_journal_head_lock;
+#endif
+#endif
};
+static inline unsigned long bh_uptodate_lock_irqsave(struct buffer_head *bh)
+{
+ unsigned long flags;
+
+#ifndef CONFIG_PREEMPT_RT_BASE
+ local_irq_save(flags);
+ bit_spin_lock(BH_Uptodate_Lock, &bh->b_state);
+#else
+ spin_lock_irqsave(&bh->b_uptodate_lock, flags);
+#endif
+ return flags;
+}
+
+static inline void
+bh_uptodate_unlock_irqrestore(struct buffer_head *bh, unsigned long flags)
+{
+#ifndef CONFIG_PREEMPT_RT_BASE
+ bit_spin_unlock(BH_Uptodate_Lock, &bh->b_state);
+ local_irq_restore(flags);
+#else
+ spin_unlock_irqrestore(&bh->b_uptodate_lock, flags);
+#endif
+}
+
+static inline void buffer_head_init_locks(struct buffer_head *bh)
+{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ spin_lock_init(&bh->b_uptodate_lock);
+#if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || \
+ defined(CONFIG_JBD2) || defined(CONFIG_JBD2_MODULE)
+ spin_lock_init(&bh->b_state_lock);
+ spin_lock_init(&bh->b_journal_head_lock);
+#endif
+#endif
+}
+
/*
* macro tricks to expand the set_buffer_foo(), clear_buffer_foo()
* and buffer_foo() functions.
diff --git a/include/linux/completion.h b/include/linux/completion.h
index 3cd574d..eb2d4ac 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -8,7 +8,7 @@
* See kernel/sched/core.c for details.
*/
-#include <linux/wait.h>
+#include <linux/wait-simple.h>
/*
* struct completion - structure used to maintain state for a "completion"
@@ -24,11 +24,11 @@
*/
struct completion {
unsigned int done;
- wait_queue_head_t wait;
+ struct swait_head wait;
};
#define COMPLETION_INITIALIZER(work) \
- { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+ { 0, SWAIT_HEAD_INITIALIZER((work).wait) }
#define COMPLETION_INITIALIZER_ONSTACK(work) \
({ init_completion(&work); work; })
@@ -73,7 +73,7 @@ struct completion {
static inline void init_completion(struct completion *x)
{
x->done = 0;
- init_waitqueue_head(&x->wait);
+ init_swait_head(&x->wait);
}
extern void wait_for_completion(struct completion *);
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 801ff9e..0c2b05c 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -179,6 +179,8 @@ extern void get_online_cpus(void);
extern void put_online_cpus(void);
extern void cpu_hotplug_disable(void);
extern void cpu_hotplug_enable(void);
+extern void pin_current_cpu(void);
+extern void unpin_current_cpu(void);
#define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
@@ -206,6 +208,8 @@ static inline void cpu_hotplug_done(void) {}
#define put_online_cpus() do { } while (0)
#define cpu_hotplug_disable() do { } while (0)
#define cpu_hotplug_enable() do { } while (0)
+static inline void pin_current_cpu(void) { }
+static inline void unpin_current_cpu(void) { }
#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
/* These aren't inline functions due to a GCC bug. */
#define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
diff --git a/include/linux/delay.h b/include/linux/delay.h
index a6ecb34..37caab3 100644
--- a/include/linux/delay.h
+++ b/include/linux/delay.h
@@ -52,4 +52,10 @@ static inline void ssleep(unsigned int seconds)
msleep(seconds * 1000);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void cpu_chill(void);
+#else
+# define cpu_chill() cpu_relax()
+#endif
+
#endif /* defined(_LINUX_DELAY_H) */
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 20aebdb..ab58c33 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -56,6 +56,9 @@ struct trace_entry {
unsigned char flags;
unsigned char preempt_count;
int pid;
+ unsigned short migrate_disable;
+ unsigned short padding;
+ unsigned char preempt_lazy_count;
};
#define FTRACE_MAX_EVENT \
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 7fb31da..821d523 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -7,6 +7,7 @@
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
+#include <linux/sched.h>
#include <asm/cacheflush.h>
@@ -85,32 +86,51 @@ static inline void __kunmap_atomic(void *addr)
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+#ifndef CONFIG_PREEMPT_RT_FULL
DECLARE_PER_CPU(int, __kmap_atomic_idx);
+#endif
static inline int kmap_atomic_idx_push(void)
{
+#ifndef CONFIG_PREEMPT_RT_FULL
int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
-#ifdef CONFIG_DEBUG_HIGHMEM
+# ifdef CONFIG_DEBUG_HIGHMEM
WARN_ON_ONCE(in_irq() && !irqs_disabled());
BUG_ON(idx > KM_TYPE_NR);
-#endif
+# endif
return idx;
+#else
+ current->kmap_idx++;
+ BUG_ON(current->kmap_idx > KM_TYPE_NR);
+ return current->kmap_idx - 1;
+#endif
}
static inline int kmap_atomic_idx(void)
{
+#ifndef CONFIG_PREEMPT_RT_FULL
return __this_cpu_read(__kmap_atomic_idx) - 1;
+#else
+ return current->kmap_idx - 1;
+#endif
}
static inline void kmap_atomic_idx_pop(void)
{
-#ifdef CONFIG_DEBUG_HIGHMEM
+#ifndef CONFIG_PREEMPT_RT_FULL
+# ifdef CONFIG_DEBUG_HIGHMEM
int idx = __this_cpu_dec_return(__kmap_atomic_idx);
BUG_ON(idx < 0);
-#else
+# else
__this_cpu_dec(__kmap_atomic_idx);
+# endif
+#else
+ current->kmap_idx--;
+# ifdef CONFIG_DEBUG_HIGHMEM
+ BUG_ON(current->kmap_idx < 0);
+# endif
#endif
}
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index d19a5c2..bdbf77db 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -111,6 +111,11 @@ struct hrtimer {
enum hrtimer_restart (*function)(struct hrtimer *);
struct hrtimer_clock_base *base;
unsigned long state;
+ struct list_head cb_entry;
+ int irqsafe;
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ ktime_t praecox;
+#endif
#ifdef CONFIG_TIMER_STATS
int start_pid;
void *start_site;
@@ -147,6 +152,7 @@ struct hrtimer_clock_base {
int index;
clockid_t clockid;
struct timerqueue_head active;
+ struct list_head expired;
ktime_t resolution;
ktime_t (*get_time)(void);
ktime_t softirq_time;
@@ -190,6 +196,9 @@ struct hrtimer_cpu_base {
unsigned long nr_hangs;
ktime_t max_hang_time;
#endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+ wait_queue_head_t wait;
+#endif
struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
};
@@ -385,6 +394,13 @@ static inline int hrtimer_restart(struct hrtimer *timer)
return hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
}
+/* Softirq preemption could deadlock timer removal */
+#ifdef CONFIG_PREEMPT_RT_BASE
+ extern void hrtimer_wait_for_timer(const struct hrtimer *timer);
+#else
+# define hrtimer_wait_for_timer(timer) do { cpu_relax(); } while (0)
+#endif
+
/* Query timers: */
extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
@@ -445,9 +461,8 @@ extern int schedule_hrtimeout_range_clock(ktime_t *expires,
unsigned long delta, const enum hrtimer_mode mode, int clock);
extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);
-/* Soft interrupt function to run the hrtimer queues: */
+/* Called from the periodic timer tick */
extern void hrtimer_run_queues(void);
-extern void hrtimer_run_pending(void);
/* Bootup initialization: */
extern void __init hrtimers_init(void);
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 871a213..267527b 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -92,10 +92,14 @@ void idr_init(struct idr *idp);
* Each idr_preload() should be matched with an invocation of this
* function. See idr_preload() for details.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+void idr_preload_end(void);
+#else
static inline void idr_preload_end(void)
{
preempt_enable();
}
+#endif
/**
* idr_find - return pointer for given id
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 5cd0f09..766558a 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -143,9 +143,16 @@ extern struct task_group root_task_group;
# define INIT_PERF_EVENTS(tsk)
#endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define INIT_TIMER_LIST .posix_timer_list = NULL,
+#else
+# define INIT_TIMER_LIST
+#endif
+
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
# define INIT_VTIME(tsk) \
- .vtime_seqlock = __SEQLOCK_UNLOCKED(tsk.vtime_seqlock), \
+ .vtime_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.vtime_lock), \
+ .vtime_seq = SEQCNT_ZERO, \
.vtime_snap = 0, \
.vtime_snap_whence = VTIME_SYS,
#else
@@ -207,6 +214,7 @@ extern struct task_group root_task_group;
.cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \
.pi_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock), \
.timer_slack_ns = 50000, /* 50 usec default slack */ \
+ INIT_TIMER_LIST \
.pids = { \
[PIDTYPE_PID] = INIT_PID_LINK(PIDTYPE_PID), \
[PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID), \
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 5e865b5..a2609fb 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -58,6 +58,7 @@
* IRQF_NO_THREAD - Interrupt cannot be threaded
* IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
* resume time.
+ * IRQF_NO_SOFTIRQ_CALL - Do not process softirqs in the irq thread context (RT)
*/
#define IRQF_DISABLED 0x00000020
#define IRQF_SHARED 0x00000080
@@ -71,6 +72,7 @@
#define IRQF_FORCE_RESUME 0x00008000
#define IRQF_NO_THREAD 0x00010000
#define IRQF_EARLY_RESUME 0x00020000
+#define IRQF_NO_SOFTIRQ_CALL 0x00040000
#define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
@@ -176,7 +178,7 @@ extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
#ifdef CONFIG_LOCKDEP
# define local_irq_enable_in_hardirq() do { } while (0)
#else
-# define local_irq_enable_in_hardirq() local_irq_enable()
+# define local_irq_enable_in_hardirq() local_irq_enable_nort()
#endif
extern void disable_irq_nosync(unsigned int irq);
@@ -220,6 +222,7 @@ struct irq_affinity_notify {
unsigned int irq;
struct kref kref;
struct work_struct work;
+ struct list_head list;
void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
void (*release)(struct kref *ref);
};
@@ -314,9 +317,13 @@ static inline int disable_irq_wake(unsigned int irq)
#ifdef CONFIG_IRQ_FORCED_THREADING
+# ifndef CONFIG_PREEMPT_RT_BASE
extern bool force_irqthreads;
+# else
+# define force_irqthreads (true)
+# endif
#else
-#define force_irqthreads (0)
+#define force_irqthreads (false)
#endif
#ifndef __ARCH_SET_SOFTIRQ_PENDING
@@ -372,8 +379,14 @@ struct softirq_action
void (*action)(struct softirq_action *);
};
+#ifndef CONFIG_PREEMPT_RT_FULL
asmlinkage void do_softirq(void);
asmlinkage void __do_softirq(void);
+static inline void thread_do_softirq(void) { do_softirq(); }
+#else
+extern void thread_do_softirq(void);
+#endif
+
extern void open_softirq(int nr, void (*action)(struct softirq_action *));
extern void softirq_init(void);
extern void __raise_softirq_irqoff(unsigned int nr);
@@ -381,6 +394,8 @@ extern void __raise_softirq_irqoff(unsigned int nr);
extern void raise_softirq_irqoff(unsigned int nr);
extern void raise_softirq(unsigned int nr);
+extern void softirq_check_pending_idle(void);
+
/* This is the worklist that queues up per-cpu softirq work.
*
* send_remote_sendirq() adds work to these lists, and
@@ -421,8 +436,9 @@ extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
to be executed on some cpu at least once after this.
* If the tasklet is already scheduled, but its execution is still not
started, it will be executed only once.
- * If this tasklet is already running on another CPU (or schedule is called
- from tasklet itself), it is rescheduled for later.
+ * If this tasklet is already running on another CPU, it is rescheduled
+ for later.
+ * Schedule must not be called from the tasklet itself (a lockup occurs)
* Tasklet is strictly serialized wrt itself, but not
wrt another tasklets. If client needs some intertask synchronization,
he makes it with spinlocks.
@@ -447,27 +463,36 @@ struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
enum
{
TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
- TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
+ TASKLET_STATE_RUN, /* Tasklet is running (SMP only) */
+ TASKLET_STATE_PENDING /* Tasklet is pending */
};
-#ifdef CONFIG_SMP
+#define TASKLET_STATEF_SCHED (1 << TASKLET_STATE_SCHED)
+#define TASKLET_STATEF_RUN (1 << TASKLET_STATE_RUN)
+#define TASKLET_STATEF_PENDING (1 << TASKLET_STATE_PENDING)
+
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
static inline int tasklet_trylock(struct tasklet_struct *t)
{
return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
}
+static inline int tasklet_tryunlock(struct tasklet_struct *t)
+{
+ return cmpxchg(&t->state, TASKLET_STATEF_RUN, 0) == TASKLET_STATEF_RUN;
+}
+
static inline void tasklet_unlock(struct tasklet_struct *t)
{
smp_mb__before_clear_bit();
clear_bit(TASKLET_STATE_RUN, &(t)->state);
}
-static inline void tasklet_unlock_wait(struct tasklet_struct *t)
-{
- while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
-}
+extern void tasklet_unlock_wait(struct tasklet_struct *t);
+
#else
#define tasklet_trylock(t) 1
+#define tasklet_tryunlock(t) 1
#define tasklet_unlock_wait(t) do { } while (0)
#define tasklet_unlock(t) do { } while (0)
#endif
@@ -516,17 +541,8 @@ static inline void tasklet_disable(struct tasklet_struct *t)
smp_mb();
}
-static inline void tasklet_enable(struct tasklet_struct *t)
-{
- smp_mb__before_atomic_dec();
- atomic_dec(&t->count);
-}
-
-static inline void tasklet_hi_enable(struct tasklet_struct *t)
-{
- smp_mb__before_atomic_dec();
- atomic_dec(&t->count);
-}
+extern void tasklet_enable(struct tasklet_struct *t);
+extern void tasklet_hi_enable(struct tasklet_struct *t);
extern void tasklet_kill(struct tasklet_struct *t);
extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
@@ -558,6 +574,12 @@ void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
tasklet_kill(&ttimer->tasklet);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void softirq_early_init(void);
+#else
+static inline void softirq_early_init(void) { }
+#endif
+
/*
* Autoprobing for irqs:
*
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 56bb0dc..e2d8789 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -70,6 +70,7 @@ typedef void (*irq_preflow_handler_t)(struct irq_data *data);
* IRQ_MOVE_PCNTXT - Interrupt can be migrated from process context
* IRQ_NESTED_TRHEAD - Interrupt nests into another thread
* IRQ_PER_CPU_DEVID - Dev_id is a per-cpu variable
+ * IRQ_NO_SOFTIRQ_CALL - No softirq processing in the irq thread context (RT)
*/
enum {
IRQ_TYPE_NONE = 0x00000000,
@@ -94,12 +95,14 @@ enum {
IRQ_NESTED_THREAD = (1 << 15),
IRQ_NOTHREAD = (1 << 16),
IRQ_PER_CPU_DEVID = (1 << 17),
+ IRQ_NO_SOFTIRQ_CALL = (1 << 18),
};
#define IRQF_MODIFY_MASK \
(IRQ_TYPE_SENSE_MASK | IRQ_NOPROBE | IRQ_NOREQUEST | \
IRQ_NOAUTOEN | IRQ_MOVE_PCNTXT | IRQ_LEVEL | IRQ_NO_BALANCING | \
- IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID)
+ IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID | \
+ IRQ_NO_SOFTIRQ_CALL)
#define IRQ_NO_BALANCING_MASK (IRQ_PER_CPU | IRQ_NO_BALANCING)
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 6601702..60c19ee 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -16,6 +16,7 @@
#define IRQ_WORK_BUSY 2UL
#define IRQ_WORK_FLAGS 3UL
#define IRQ_WORK_LAZY 4UL /* Doesn't want IPI, wait for tick */
+#define IRQ_WORK_HARD_IRQ 8UL /* Run hard IRQ context, even on RT */
struct irq_work {
unsigned long flags;
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 56fb646..da992bc 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -52,6 +52,7 @@ struct irq_desc {
unsigned int irq_count; /* For detecting broken IRQs */
unsigned long last_unhandled; /* Aging timer for unhandled count */
unsigned int irqs_unhandled;
+ u64 random_ip;
raw_spinlock_t lock;
struct cpumask *percpu_enabled;
#ifdef CONFIG_SMP
diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h
index d176d65..0977829 100644
--- a/include/linux/irqflags.h
+++ b/include/linux/irqflags.h
@@ -25,8 +25,6 @@
# define trace_softirqs_enabled(p) ((p)->softirqs_enabled)
# define trace_hardirq_enter() do { current->hardirq_context++; } while (0)
# define trace_hardirq_exit() do { current->hardirq_context--; } while (0)
-# define lockdep_softirq_enter() do { current->softirq_context++; } while (0)
-# define lockdep_softirq_exit() do { current->softirq_context--; } while (0)
# define INIT_TRACE_IRQFLAGS .softirqs_enabled = 1,
#else
# define trace_hardirqs_on() do { } while (0)
@@ -39,9 +37,15 @@
# define trace_softirqs_enabled(p) 0
# define trace_hardirq_enter() do { } while (0)
# define trace_hardirq_exit() do { } while (0)
+# define INIT_TRACE_IRQFLAGS
+#endif
+
+#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT_FULL)
+# define lockdep_softirq_enter() do { current->softirq_context++; } while (0)
+# define lockdep_softirq_exit() do { current->softirq_context--; } while (0)
+#else
# define lockdep_softirq_enter() do { } while (0)
# define lockdep_softirq_exit() do { } while (0)
-# define INIT_TRACE_IRQFLAGS
#endif
#if defined(CONFIG_IRQSOFF_TRACER) || \
@@ -147,4 +151,23 @@
#endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
+/*
+ * local_irq* variants depending on RT/!RT
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define local_irq_disable_nort() do { } while (0)
+# define local_irq_enable_nort() do { } while (0)
+# define local_irq_save_nort(flags) local_save_flags(flags)
+# define local_irq_restore_nort(flags) (void)(flags)
+# define local_irq_disable_rt() local_irq_disable()
+# define local_irq_enable_rt() local_irq_enable()
+#else
+# define local_irq_disable_nort() local_irq_disable()
+# define local_irq_enable_nort() local_irq_enable()
+# define local_irq_save_nort(flags) local_irq_save(flags)
+# define local_irq_restore_nort(flags) local_irq_restore(flags)
+# define local_irq_disable_rt() do { } while (0)
+# define local_irq_enable_rt() do { } while (0)
+#endif
+
#endif
diff --git a/include/linux/jbd_common.h b/include/linux/jbd_common.h
index 3dc5343..a90a6f5 100644
--- a/include/linux/jbd_common.h
+++ b/include/linux/jbd_common.h
@@ -15,32 +15,56 @@ static inline struct journal_head *bh2jh(struct buffer_head *bh)
static inline void jbd_lock_bh_state(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_lock(BH_State, &bh->b_state);
+#else
+ spin_lock(&bh->b_state_lock);
+#endif
}
static inline int jbd_trylock_bh_state(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
return bit_spin_trylock(BH_State, &bh->b_state);
+#else
+ return spin_trylock(&bh->b_state_lock);
+#endif
}
static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
return bit_spin_is_locked(BH_State, &bh->b_state);
+#else
+ return spin_is_locked(&bh->b_state_lock);
+#endif
}
static inline void jbd_unlock_bh_state(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_unlock(BH_State, &bh->b_state);
+#else
+ spin_unlock(&bh->b_state_lock);
+#endif
}
static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_lock(BH_JournalHead, &bh->b_state);
+#else
+ spin_lock(&bh->b_journal_head_lock);
+#endif
}
static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_unlock(BH_JournalHead, &bh->b_state);
+#else
+ spin_unlock(&bh->b_journal_head_lock);
+#endif
}
#endif
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index a507907..006627b 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -49,7 +49,8 @@
#include <linux/types.h>
#include <linux/compiler.h>
-#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
+#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) && \
+ !defined(CONFIG_PREEMPT_BASE)
struct static_key {
atomic_t enabled;
diff --git a/include/linux/kdb.h b/include/linux/kdb.h
index 7f6fe6e..680ad23 100644
--- a/include/linux/kdb.h
+++ b/include/linux/kdb.h
@@ -115,7 +115,7 @@ extern int kdb_trap_printk;
extern __printf(1, 0) int vkdb_printf(const char *fmt, va_list args);
extern __printf(1, 2) int kdb_printf(const char *, ...);
typedef __printf(1, 2) int (*kdb_printf_t)(const char *, ...);
-
+#define in_kdb_printk() (kdb_trap_printk)
extern void kdb_init(int level);
/* Access to kdb specific polling devices */
@@ -150,6 +150,7 @@ extern int kdb_register_repeat(char *, kdb_func_t, char *, char *,
extern int kdb_unregister(char *);
#else /* ! CONFIG_KGDB_KDB */
static inline __printf(1, 2) int kdb_printf(const char *fmt, ...) { return 0; }
+#define in_kdb_printk() (0)
static inline void kdb_init(int level) {}
static inline int kdb_register(char *cmd, kdb_func_t func, char *usage,
char *help, short minlen) { return 0; }
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 672ddc4..c34e608 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -412,6 +412,7 @@ extern enum system_states {
SYSTEM_HALT,
SYSTEM_POWER_OFF,
SYSTEM_RESTART,
+ SYSTEM_SUSPEND,
} system_state;
#define TAINT_PROPRIETARY_MODULE 0
diff --git a/include/linux/lglock.h b/include/linux/lglock.h
index 0d24e93..d2c0d6d 100644
--- a/include/linux/lglock.h
+++ b/include/linux/lglock.h
@@ -42,22 +42,37 @@
#endif
struct lglock {
+#ifndef CONFIG_PREEMPT_RT_FULL
arch_spinlock_t __percpu *lock;
+#else
+ struct rt_mutex __percpu *lock;
+#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lock_class_key lock_key;
struct lockdep_map lock_dep_map;
#endif
};
-#define DEFINE_LGLOCK(name) \
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define DEFINE_LGLOCK(name) \
static DEFINE_PER_CPU(arch_spinlock_t, name ## _lock) \
= __ARCH_SPIN_LOCK_UNLOCKED; \
struct lglock name = { .lock = &name ## _lock }
-#define DEFINE_STATIC_LGLOCK(name) \
+# define DEFINE_STATIC_LGLOCK(name) \
static DEFINE_PER_CPU(arch_spinlock_t, name ## _lock) \
= __ARCH_SPIN_LOCK_UNLOCKED; \
static struct lglock name = { .lock = &name ## _lock }
+#else
+
+# define DEFINE_LGLOCK(name) \
+ static DEFINE_PER_CPU(struct rt_mutex, name ## _lock); \
+ struct lglock name = { .lock = &name ## _lock }
+
+# define DEFINE_STATIC_LGLOCK(name) \
+ static DEFINE_PER_CPU(struct rt_mutex, name ## _lock); \
+ static struct lglock name = { .lock = &name ## _lock }
+#endif
void lg_lock_init(struct lglock *lg, char *name);
void lg_local_lock(struct lglock *lg);
diff --git a/include/linux/list.h b/include/linux/list.h
index f4d8a2f..885943e 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -373,6 +373,17 @@ static inline void list_splice_tail_init(struct list_head *list,
(!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL)
/**
+ * list_last_entry - get the last element from a list
+ * @ptr: the list head to take the element from.
+ * @type: the type of the struct this is embedded in.
+ * @member: the name of the list_struct within the struct.
+ *
+ * Note, that list is expected to be not empty.
+ */
+#define list_last_entry(ptr, type, member) \
+ list_entry((ptr)->prev, type, member)
+
+/**
* list_for_each - iterate over a list
* @pos: the &struct list_head to use as a loop cursor.
* @head: the head for your list.
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 2eb8855..d8876a0 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -2,6 +2,7 @@
#define _LINUX_LIST_BL_H
#include <linux/list.h>
+#include <linux/spinlock.h>
#include <linux/bit_spinlock.h>
/*
@@ -32,13 +33,22 @@
struct hlist_bl_head {
struct hlist_bl_node *first;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ raw_spinlock_t lock;
+#endif
};
struct hlist_bl_node {
struct hlist_bl_node *next, **pprev;
};
-#define INIT_HLIST_BL_HEAD(ptr) \
- ((ptr)->first = NULL)
+
+static inline void INIT_HLIST_BL_HEAD(struct hlist_bl_head *h)
+{
+ h->first = NULL;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ raw_spin_lock_init(&h->lock);
+#endif
+}
static inline void INIT_HLIST_BL_NODE(struct hlist_bl_node *h)
{
@@ -117,12 +127,26 @@ static inline void hlist_bl_del_init(struct hlist_bl_node *n)
static inline void hlist_bl_lock(struct hlist_bl_head *b)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_lock(0, (unsigned long *)b);
+#else
+ raw_spin_lock(&b->lock);
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+ __set_bit(0, (unsigned long *)b);
+#endif
+#endif
}
static inline void hlist_bl_unlock(struct hlist_bl_head *b)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
__bit_spin_unlock(0, (unsigned long *)b);
+#else
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+ __clear_bit(0, (unsigned long *)b);
+#endif
+ raw_spin_unlock(&b->lock);
+#endif
}
static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
diff --git a/include/linux/locallock.h b/include/linux/locallock.h
new file mode 100644
index 0000000..21653e9
--- /dev/null
+++ b/include/linux/locallock.h
@@ -0,0 +1,270 @@
+#ifndef _LINUX_LOCALLOCK_H
+#define _LINUX_LOCALLOCK_H
+
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define LL_WARN(cond) WARN_ON(cond)
+#else
+# define LL_WARN(cond) do { } while (0)
+#endif
+
+/*
+ * per cpu lock based substitute for local_irq_*()
+ */
+struct local_irq_lock {
+ spinlock_t lock;
+ struct task_struct *owner;
+ int nestcnt;
+ unsigned long flags;
+};
+
+#define DEFINE_LOCAL_IRQ_LOCK(lvar) \
+ DEFINE_PER_CPU(struct local_irq_lock, lvar) = { \
+ .lock = __SPIN_LOCK_UNLOCKED((lvar).lock) }
+
+#define DECLARE_LOCAL_IRQ_LOCK(lvar) \
+ DECLARE_PER_CPU(struct local_irq_lock, lvar)
+
+#define local_irq_lock_init(lvar) \
+ do { \
+ int __cpu; \
+ for_each_possible_cpu(__cpu) \
+ spin_lock_init(&per_cpu(lvar, __cpu).lock); \
+ } while (0)
+
+/*
+ * spin_lock|trylock|unlock_local flavour that does not migrate disable
+ * used for __local_lock|trylock|unlock where get_local_var/put_local_var
+ * already takes care of the migrate_disable/enable
+ * for CONFIG_PREEMPT_BASE map to the normal spin_* calls.
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define spin_lock_local(lock) rt_spin_lock(lock)
+# define spin_trylock_local(lock) rt_spin_trylock(lock)
+# define spin_unlock_local(lock) rt_spin_unlock(lock)
+#else
+# define spin_lock_local(lock) spin_lock(lock)
+# define spin_trylock_local(lock) spin_trylock(lock)
+# define spin_unlock_local(lock) spin_unlock(lock)
+#endif
+
+static inline void __local_lock(struct local_irq_lock *lv)
+{
+ if (lv->owner != current) {
+ spin_lock_local(&lv->lock);
+ LL_WARN(lv->owner);
+ LL_WARN(lv->nestcnt);
+ lv->owner = current;
+ }
+ lv->nestcnt++;
+}
+
+#define local_lock(lvar) \
+ do { __local_lock(&get_local_var(lvar)); } while (0)
+
+static inline int __local_trylock(struct local_irq_lock *lv)
+{
+ if (lv->owner != current && spin_trylock_local(&lv->lock)) {
+ LL_WARN(lv->owner);
+ LL_WARN(lv->nestcnt);
+ lv->owner = current;
+ lv->nestcnt = 1;
+ return 1;
+ }
+ return 0;
+}
+
+#define local_trylock(lvar) \
+ ({ \
+ int __locked; \
+ __locked = __local_trylock(&get_local_var(lvar)); \
+ if (!__locked) \
+ put_local_var(lvar); \
+ __locked; \
+ })
+
+static inline void __local_unlock(struct local_irq_lock *lv)
+{
+ LL_WARN(lv->nestcnt == 0);
+ LL_WARN(lv->owner != current);
+ if (--lv->nestcnt)
+ return;
+
+ lv->owner = NULL;
+ spin_unlock_local(&lv->lock);
+}
+
+#define local_unlock(lvar) \
+ do { \
+ __local_unlock(&__get_cpu_var(lvar)); \
+ put_local_var(lvar); \
+ } while (0)
+
+static inline void __local_lock_irq(struct local_irq_lock *lv)
+{
+ spin_lock_irqsave(&lv->lock, lv->flags);
+ LL_WARN(lv->owner);
+ LL_WARN(lv->nestcnt);
+ lv->owner = current;
+ lv->nestcnt = 1;
+}
+
+#define local_lock_irq(lvar) \
+ do { __local_lock_irq(&get_local_var(lvar)); } while (0)
+
+#define local_lock_irq_on(lvar, cpu) \
+ do { __local_lock_irq(&per_cpu(lvar, cpu)); } while (0)
+
+static inline void __local_unlock_irq(struct local_irq_lock *lv)
+{
+ LL_WARN(!lv->nestcnt);
+ LL_WARN(lv->owner != current);
+ lv->owner = NULL;
+ lv->nestcnt = 0;
+ spin_unlock_irq(&lv->lock);
+}
+
+#define local_unlock_irq(lvar) \
+ do { \
+ __local_unlock_irq(&__get_cpu_var(lvar)); \
+ put_local_var(lvar); \
+ } while (0)
+
+#define local_unlock_irq_on(lvar, cpu) \
+ do { \
+ __local_unlock_irq(&per_cpu(lvar, cpu)); \
+ } while (0)
+
+static inline int __local_lock_irqsave(struct local_irq_lock *lv)
+{
+ if (lv->owner != current) {
+ __local_lock_irq(lv);
+ return 0;
+ } else {
+ lv->nestcnt++;
+ return 1;
+ }
+}
+
+#define local_lock_irqsave(lvar, _flags) \
+ do { \
+ if (__local_lock_irqsave(&get_local_var(lvar))) \
+ put_local_var(lvar); \
+ _flags = __get_cpu_var(lvar).flags; \
+ } while (0)
+
+#define local_lock_irqsave_on(lvar, _flags, cpu) \
+ do { \
+ __local_lock_irqsave(&per_cpu(lvar, cpu)); \
+ _flags = per_cpu(lvar, cpu).flags; \
+ } while (0)
+
+static inline int __local_unlock_irqrestore(struct local_irq_lock *lv,
+ unsigned long flags)
+{
+ LL_WARN(!lv->nestcnt);
+ LL_WARN(lv->owner != current);
+ if (--lv->nestcnt)
+ return 0;
+
+ lv->owner = NULL;
+ spin_unlock_irqrestore(&lv->lock, lv->flags);
+ return 1;
+}
+
+#define local_unlock_irqrestore(lvar, flags) \
+ do { \
+ if (__local_unlock_irqrestore(&__get_cpu_var(lvar), flags)) \
+ put_local_var(lvar); \
+ } while (0)
+
+#define local_unlock_irqrestore_on(lvar, flags, cpu) \
+ do { \
+ __local_unlock_irqrestore(&per_cpu(lvar, cpu), flags); \
+ } while (0)
+
+#define local_spin_trylock_irq(lvar, lock) \
+ ({ \
+ int __locked; \
+ local_lock_irq(lvar); \
+ __locked = spin_trylock(lock); \
+ if (!__locked) \
+ local_unlock_irq(lvar); \
+ __locked; \
+ })
+
+#define local_spin_lock_irq(lvar, lock) \
+ do { \
+ local_lock_irq(lvar); \
+ spin_lock(lock); \
+ } while (0)
+
+#define local_spin_unlock_irq(lvar, lock) \
+ do { \
+ spin_unlock(lock); \
+ local_unlock_irq(lvar); \
+ } while (0)
+
+#define local_spin_lock_irqsave(lvar, lock, flags) \
+ do { \
+ local_lock_irqsave(lvar, flags); \
+ spin_lock(lock); \
+ } while (0)
+
+#define local_spin_unlock_irqrestore(lvar, lock, flags) \
+ do { \
+ spin_unlock(lock); \
+ local_unlock_irqrestore(lvar, flags); \
+ } while (0)
+
+#define get_locked_var(lvar, var) \
+ (*({ \
+ local_lock(lvar); \
+ &__get_cpu_var(var); \
+ }))
+
+#define put_locked_var(lvar, var) local_unlock(lvar);
+
+#define local_lock_cpu(lvar) \
+ ({ \
+ local_lock(lvar); \
+ smp_processor_id(); \
+ })
+
+#define local_unlock_cpu(lvar) local_unlock(lvar)
+
+#else /* PREEMPT_RT_BASE */
+
+#define DEFINE_LOCAL_IRQ_LOCK(lvar) __typeof__(const int) lvar
+#define DECLARE_LOCAL_IRQ_LOCK(lvar) extern __typeof__(const int) lvar
+
+static inline void local_irq_lock_init(int lvar) { }
+
+#define local_lock(lvar) preempt_disable()
+#define local_unlock(lvar) preempt_enable()
+#define local_lock_irq(lvar) local_irq_disable()
+#define local_unlock_irq(lvar) local_irq_enable()
+#define local_lock_irqsave(lvar, flags) local_irq_save(flags)
+#define local_unlock_irqrestore(lvar, flags) local_irq_restore(flags)
+
+#define local_spin_trylock_irq(lvar, lock) spin_trylock_irq(lock)
+#define local_spin_lock_irq(lvar, lock) spin_lock_irq(lock)
+#define local_spin_unlock_irq(lvar, lock) spin_unlock_irq(lock)
+#define local_spin_lock_irqsave(lvar, lock, flags) \
+ spin_lock_irqsave(lock, flags)
+#define local_spin_unlock_irqrestore(lvar, lock, flags) \
+ spin_unlock_irqrestore(lock, flags)
+
+#define get_locked_var(lvar, var) get_cpu_var(var)
+#define put_locked_var(lvar, var) put_cpu_var(var)
+
+#define local_lock_cpu(lvar) get_cpu()
+#define local_unlock_cpu(lvar) put_cpu()
+
+#endif
+
+#endif
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0737343..2acbab4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1252,27 +1252,59 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a
* overflow into the next struct page (as it might with DEBUG_SPINLOCK).
* When freeing, reset page->mapping so free_pages_check won't complain.
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
+
#define __pte_lockptr(page) &((page)->ptl)
-#define pte_lock_init(_page) do { \
- spin_lock_init(__pte_lockptr(_page)); \
-} while (0)
+
+static inline struct page *pte_lock_init(struct page *page)
+{
+ spin_lock_init(__pte_lockptr(page));
+ return page;
+}
+
#define pte_lock_deinit(page) ((page)->mapping = NULL)
+
+#else /* !PREEMPT_RT_FULL */
+
+/*
+ * On PREEMPT_RT_FULL the spinlock_t's are too large to embed in the
+ * page frame, hence it only has a pointer and we need to dynamically
+ * allocate the lock when we allocate PTE-pages.
+ *
+ * This is an overall win, since only a small fraction of the pages
+ * will be PTE pages under normal circumstances.
+ */
+
+#define __pte_lockptr(page) ((page)->ptl)
+
+extern struct page *pte_lock_init(struct page *page);
+extern void pte_lock_deinit(struct page *page);
+
+#endif /* PREEMPT_RT_FULL */
+
#define pte_lockptr(mm, pmd) ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
#else /* !USE_SPLIT_PTLOCKS */
/*
* We use mm->page_table_lock to guard all pagetable pages of the mm.
*/
-#define pte_lock_init(page) do {} while (0)
+static inline struct page *pte_lock_init(struct page *page) { return page; }
#define pte_lock_deinit(page) do {} while (0)
#define pte_lockptr(mm, pmd) ({(void)(pmd); &(mm)->page_table_lock;})
#endif /* USE_SPLIT_PTLOCKS */
-static inline void pgtable_page_ctor(struct page *page)
+static inline struct page *__pgtable_page_ctor(struct page *page)
{
- pte_lock_init(page);
- inc_zone_page_state(page, NR_PAGETABLE);
+ page = pte_lock_init(page);
+ if (page)
+ inc_zone_page_state(page, NR_PAGETABLE);
+ return page;
}
+#define pgtable_page_ctor(page) \
+do { \
+ page = __pgtable_page_ctor(page); \
+} while (0)
+
static inline void pgtable_page_dtor(struct page *page)
{
pte_lock_deinit(page);
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 8e082f1..d87823c 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -11,6 +11,7 @@
#include <linux/completion.h>
#include <linux/cpumask.h>
#include <linux/page-debug-flags.h>
+#include <linux/rcupdate.h>
#include <linux/uprobes.h>
#include <linux/page-flags-layout.h>
#include <asm/page.h>
@@ -142,7 +143,11 @@ struct page {
* system if PG_buddy is set.
*/
#if USE_SPLIT_PTLOCKS
+# ifndef CONFIG_PREEMPT_RT_FULL
spinlock_t ptl;
+# else
+ spinlock_t *ptl;
+# endif
#endif
struct kmem_cache *slab_cache; /* SL[AU]B: Pointer to slab */
struct page *first_page; /* Compound tail pages */
@@ -444,6 +449,9 @@ struct mm_struct {
bool tlb_flush_pending;
#endif
struct uprobes_state uprobes_state;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ struct rcu_head delayed_drop;
+#endif
};
/* first nid will either be a valid NID or one of these values */
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index bab49da..79e172a 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -18,6 +18,17 @@
#include <linux/atomic.h>
#include <asm/processor.h>
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
+ , .dep_map = { .name = #lockname }
+#else
+# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
+#endif
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/mutex_rt.h>
+#else
+
/*
* Simple, straightforward mutexes with strict semantics:
*
@@ -99,13 +110,6 @@ do { \
static inline void mutex_destroy(struct mutex *lock) {}
#endif
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
- , .dep_map = { .name = #lockname }
-#else
-# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
-#endif
-
#define __MUTEX_INITIALIZER(lockname) \
{ .count = ATOMIC_INIT(1) \
, .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \
@@ -173,6 +177,8 @@ extern int __must_check mutex_lock_killable(struct mutex *lock);
extern int mutex_trylock(struct mutex *lock);
extern void mutex_unlock(struct mutex *lock);
+#endif /* !PREEMPT_RT_FULL */
+
extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
#ifndef arch_mutex_cpu_relax
diff --git a/include/linux/mutex_rt.h b/include/linux/mutex_rt.h
new file mode 100644
index 0000000..c38a44b
--- /dev/null
+++ b/include/linux/mutex_rt.h
@@ -0,0 +1,84 @@
+#ifndef __LINUX_MUTEX_RT_H
+#define __LINUX_MUTEX_RT_H
+
+#ifndef __LINUX_MUTEX_H
+#error "Please include mutex.h"
+#endif
+
+#include <linux/rtmutex.h>
+
+/* FIXME: Just for __lockfunc */
+#include <linux/spinlock.h>
+
+struct mutex {
+ struct rt_mutex lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+};
+
+#define __MUTEX_INITIALIZER(mutexname) \
+ { \
+ .lock = __RT_MUTEX_INITIALIZER(mutexname.lock) \
+ __DEP_MAP_MUTEX_INITIALIZER(mutexname) \
+ }
+
+#define DEFINE_MUTEX(mutexname) \
+ struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
+
+extern void __mutex_do_init(struct mutex *lock, const char *name, struct lock_class_key *key);
+extern void __lockfunc _mutex_lock(struct mutex *lock);
+extern int __lockfunc _mutex_lock_interruptible(struct mutex *lock);
+extern int __lockfunc _mutex_lock_killable(struct mutex *lock);
+extern void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass);
+extern void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
+extern int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_trylock(struct mutex *lock);
+extern void __lockfunc _mutex_unlock(struct mutex *lock);
+
+#define mutex_is_locked(l) rt_mutex_is_locked(&(l)->lock)
+#define mutex_lock(l) _mutex_lock(l)
+#define mutex_lock_interruptible(l) _mutex_lock_interruptible(l)
+#define mutex_lock_killable(l) _mutex_lock_killable(l)
+#define mutex_trylock(l) _mutex_trylock(l)
+#define mutex_unlock(l) _mutex_unlock(l)
+#define mutex_destroy(l) rt_mutex_destroy(&(l)->lock)
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define mutex_lock_nested(l, s) _mutex_lock_nested(l, s)
+# define mutex_lock_interruptible_nested(l, s) \
+ _mutex_lock_interruptible_nested(l, s)
+# define mutex_lock_killable_nested(l, s) \
+ _mutex_lock_killable_nested(l, s)
+
+# define mutex_lock_nest_lock(lock, nest_lock) \
+do { \
+ typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \
+ _mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \
+} while (0)
+
+#else
+# define mutex_lock_nested(l, s) _mutex_lock(l)
+# define mutex_lock_interruptible_nested(l, s) \
+ _mutex_lock_interruptible(l)
+# define mutex_lock_killable_nested(l, s) \
+ _mutex_lock_killable(l)
+# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
+#endif
+
+# define mutex_init(mutex) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ rt_mutex_init(&(mutex)->lock); \
+ __mutex_do_init((mutex), #mutex, &__key); \
+} while (0)
+
+# define __mutex_init(mutex, name, key) \
+do { \
+ rt_mutex_init(&(mutex)->lock); \
+ __mutex_do_init((mutex), name, key); \
+} while (0)
+
+#endif
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d150284..9963e18 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1217,7 +1217,7 @@ struct net_device {
unsigned char perm_addr[MAX_ADDR_LEN]; /* permanent hw address */
unsigned char addr_assign_type; /* hw address assignment type */
unsigned char addr_len; /* hardware address length */
- unsigned char neigh_priv_len;
+ unsigned short neigh_priv_len;
unsigned short dev_id; /* Used to differentiate devices
* that share the same link
* layer address
@@ -1935,6 +1935,7 @@ struct softnet_data {
unsigned int dropped;
struct sk_buff_head input_pkt_queue;
struct napi_struct backlog;
+ struct sk_buff_head tofree_queue;
#ifdef CONFIG_NET_FLOW_LIMIT
struct sd_flow_limit __rcu *flow_limit;
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index dd49566..7d083af 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -3,6 +3,7 @@
#include <linux/netdevice.h>
+#include <linux/locallock.h>
#include <uapi/linux/netfilter/x_tables.h>
/**
@@ -284,6 +285,8 @@ extern void xt_free_table_info(struct xt_table_info *info);
*/
DECLARE_PER_CPU(seqcount_t, xt_recseq);
+DECLARE_LOCAL_IRQ_LOCK(xt_write_lock);
+
/**
* xt_write_recseq_begin - start of a write section
*
@@ -298,6 +301,9 @@ static inline unsigned int xt_write_recseq_begin(void)
{
unsigned int addend;
+ /* RT protection */
+ local_lock(xt_write_lock);
+
/*
* Low order bit of sequence is set if we already
* called xt_write_recseq_begin().
@@ -328,6 +334,7 @@ static inline void xt_write_recseq_end(unsigned int addend)
/* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
smp_wmb();
__this_cpu_add(xt_recseq.sequence, addend);
+ local_unlock(xt_write_lock);
}
/*
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index d14a4c3..2e4414a 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -6,7 +6,7 @@
*
* Alan Cox <Alan.Cox@linux.org>
*/
-
+
#ifndef _LINUX_NOTIFIER_H
#define _LINUX_NOTIFIER_H
#include <linux/errno.h>
@@ -42,9 +42,7 @@
* in srcu_notifier_call_chain(): no cache bounces and no memory barriers.
* As compensation, srcu_notifier_chain_unregister() is rather expensive.
* SRCU notifier chains should be used when the chain will be called very
- * often but notifier_blocks will seldom be removed. Also, SRCU notifier
- * chains are slightly more difficult to use because they require special
- * runtime initialization.
+ * often but notifier_blocks will seldom be removed.
*/
typedef int (*notifier_fn_t)(struct notifier_block *nb,
@@ -88,7 +86,7 @@ struct srcu_notifier_head {
(name)->head = NULL; \
} while (0)
-/* srcu_notifier_heads must be initialized and cleaned up dynamically */
+/* srcu_notifier_heads must be cleaned up dynamically */
extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
#define srcu_cleanup_notifier_head(name) \
cleanup_srcu_struct(&(name)->srcu);
@@ -101,7 +99,13 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
.head = NULL }
#define RAW_NOTIFIER_INIT(name) { \
.head = NULL }
-/* srcu_notifier_heads cannot be initialized statically */
+
+#define SRCU_NOTIFIER_INIT(name, pcpu) \
+ { \
+ .mutex = __MUTEX_INITIALIZER(name.mutex), \
+ .head = NULL, \
+ .srcu = __SRCU_STRUCT_INIT(name.srcu, pcpu), \
+ }
#define ATOMIC_NOTIFIER_HEAD(name) \
struct atomic_notifier_head name = \
@@ -113,6 +117,18 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
struct raw_notifier_head name = \
RAW_NOTIFIER_INIT(name)
+#define _SRCU_NOTIFIER_HEAD(name, mod) \
+ static DEFINE_PER_CPU(struct srcu_struct_array, \
+ name##_head_srcu_array); \
+ mod struct srcu_notifier_head name = \
+ SRCU_NOTIFIER_INIT(name, name##_head_srcu_array)
+
+#define SRCU_NOTIFIER_HEAD(name) \
+ _SRCU_NOTIFIER_HEAD(name, )
+
+#define SRCU_NOTIFIER_HEAD_STATIC(name) \
+ _SRCU_NOTIFIER_HEAD(name, static)
+
#ifdef __KERNEL__
extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
@@ -182,12 +198,12 @@ static inline int notifier_to_errno(int ret)
/*
* Declared notifiers so far. I can imagine quite a few more chains
- * over time (eg laptop power reset chains, reboot chain (to clean
+ * over time (eg laptop power reset chains, reboot chain (to clean
* device units up), device [un]mount chain, module load/unload chain,
- * low memory chain, screenblank chain (for plug in modular screenblankers)
+ * low memory chain, screenblank chain (for plug in modular screenblankers)
* VC switch chains (for loadable kernel svgalib VC switch helpers) etc...
*/
-
+
/* CPU notfiers are defined in include/linux/cpu.h. */
/* netdevice notifiers are defined in include/linux/netdevice.h */
diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 777a524..ca67e80 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -24,6 +24,9 @@ enum {
*/
struct page_cgroup {
unsigned long flags;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ spinlock_t pcg_lock;
+#endif
struct mem_cgroup *mem_cgroup;
};
@@ -74,12 +77,20 @@ static inline void lock_page_cgroup(struct page_cgroup *pc)
* Don't take this lock in IRQ context.
* This lock is for pc->mem_cgroup, USED, MIGRATION
*/
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_lock(PCG_LOCK, &pc->flags);
+#else
+ spin_lock(&pc->pcg_lock);
+#endif
}
static inline void unlock_page_cgroup(struct page_cgroup *pc)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_unlock(PCG_LOCK, &pc->flags);
+#else
+ spin_unlock(&pc->pcg_lock);
+#endif
}
#else /* CONFIG_MEMCG */
@@ -102,6 +113,10 @@ static inline void __init page_cgroup_init_flatmem(void)
{
}
+static inline void page_cgroup_lock_init(struct page_cgroup *pc)
+{
+}
+
#endif /* CONFIG_MEMCG */
#include <linux/swap.h>
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index c74088a..f05adf5 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -48,6 +48,31 @@
preempt_enable(); \
} while (0)
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define get_local_var(var) get_cpu_var(var)
+# define put_local_var(var) put_cpu_var(var)
+# define get_local_ptr(var) get_cpu_ptr(var)
+# define put_local_ptr(var) put_cpu_ptr(var)
+#else
+# define get_local_var(var) (*({ \
+ migrate_disable(); \
+ &__get_cpu_var(var); }))
+
+# define put_local_var(var) do { \
+ (void)&(var); \
+ migrate_enable(); \
+} while (0)
+
+# define get_local_ptr(var) ({ \
+ migrate_disable(); \
+ this_cpu_ptr(var); })
+
+# define put_local_ptr(var) do { \
+ (void)(var); \
+ migrate_enable(); \
+} while (0)
+#endif
+
/* minimum unit size, also is the maximum supported allocation size */
#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 23705a5..2cc64b7 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -2,6 +2,7 @@
#define _LINUX_PID_H
#include <linux/rcupdate.h>
+#include <linux/atomic.h>
enum pid_type
{
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index f5d4723..c153cf2 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -23,15 +23,38 @@
#define preempt_count() (current_thread_info()->preempt_count)
+#ifdef CONFIG_PREEMPT_LAZY
+#define add_preempt_lazy_count(val) do { preempt_lazy_count() += (val); } while (0)
+#define sub_preempt_lazy_count(val) do { preempt_lazy_count() -= (val); } while (0)
+#define inc_preempt_lazy_count() add_preempt_lazy_count(1)
+#define dec_preempt_lazy_count() sub_preempt_lazy_count(1)
+#define preempt_lazy_count() (current_thread_info()->preempt_lazy_count)
+#else
+#define add_preempt_lazy_count(val) do { } while (0)
+#define sub_preempt_lazy_count(val) do { } while (0)
+#define inc_preempt_lazy_count() do { } while (0)
+#define dec_preempt_lazy_count() do { } while (0)
+#define preempt_lazy_count() (0)
+#endif
+
#ifdef CONFIG_PREEMPT
asmlinkage void preempt_schedule(void);
+# ifdef CONFIG_PREEMPT_LAZY
#define preempt_check_resched() \
do { \
- if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
+ if (unlikely(test_thread_flag(TIF_NEED_RESCHED) || \
+ test_thread_flag(TIF_NEED_RESCHED_LAZY))) \
preempt_schedule(); \
} while (0)
+# else
+#define preempt_check_resched() \
+do { \
+ if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
+ preempt_schedule(); \
+} while (0)
+# endif
#ifdef CONFIG_CONTEXT_TRACKING
@@ -64,17 +87,36 @@ do { \
barrier(); \
} while (0)
+#define preempt_lazy_disable() \
+do { \
+ inc_preempt_lazy_count(); \
+ barrier(); \
+} while (0)
+
#define sched_preempt_enable_no_resched() \
do { \
barrier(); \
dec_preempt_count(); \
} while (0)
-#define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+#ifndef CONFIG_PREEMPT_RT_BASE
+# define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+# define preempt_check_resched_rt() barrier()
+#else
+# define preempt_enable_no_resched() preempt_enable()
+# define preempt_check_resched_rt() preempt_check_resched()
+#endif
#define preempt_enable() \
do { \
- preempt_enable_no_resched(); \
+ sched_preempt_enable_no_resched(); \
+ barrier(); \
+ preempt_check_resched(); \
+} while (0)
+
+#define preempt_lazy_enable() \
+do { \
+ dec_preempt_lazy_count(); \
barrier(); \
preempt_check_resched(); \
} while (0)
@@ -123,9 +165,31 @@ do { \
#define preempt_disable_notrace() barrier()
#define preempt_enable_no_resched_notrace() barrier()
#define preempt_enable_notrace() barrier()
+#define preempt_check_resched_rt() barrier()
#endif /* CONFIG_PREEMPT_COUNT */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define preempt_disable_rt() preempt_disable()
+# define preempt_enable_rt() preempt_enable()
+# define preempt_disable_nort() barrier()
+# define preempt_enable_nort() barrier()
+# ifdef CONFIG_SMP
+ extern void migrate_disable(void);
+ extern void migrate_enable(void);
+# else /* CONFIG_SMP */
+# define migrate_disable() barrier()
+# define migrate_enable() barrier()
+# endif /* CONFIG_SMP */
+#else
+# define preempt_disable_rt() barrier()
+# define preempt_enable_rt() barrier()
+# define preempt_disable_nort() preempt_disable()
+# define preempt_enable_nort() preempt_enable()
+# define migrate_disable() preempt_disable()
+# define migrate_enable() preempt_enable()
+#endif
+
#ifdef CONFIG_PREEMPT_NOTIFIERS
struct preempt_notifier;
diff --git a/include/linux/preempt_mask.h b/include/linux/preempt_mask.h
index 931bc61..199f278 100644
--- a/include/linux/preempt_mask.h
+++ b/include/linux/preempt_mask.h
@@ -58,7 +58,11 @@
#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
#define NMI_OFFSET (1UL << NMI_SHIFT)
-#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
+#else
+# define SOFTIRQ_DISABLE_OFFSET (0)
+#endif
#ifndef PREEMPT_ACTIVE
#define PREEMPT_ACTIVE_BITS 1
@@ -71,9 +75,15 @@
#endif
#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
-#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
| NMI_MASK))
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define softirq_count() (preempt_count() & SOFTIRQ_MASK)
+# define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
+#else
+# define softirq_count() (0UL)
+extern int in_serving_softirq(void);
+#endif
/*
* Are we doing bottom half or hardware interrupt processing?
@@ -84,7 +94,6 @@
#define in_irq() (hardirq_count())
#define in_softirq() (softirq_count())
#define in_interrupt() (irq_count())
-#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
/*
* Are we in NMI context?
diff --git a/include/linux/printk.h b/include/linux/printk.h
index e6131a78..6add55e 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -101,9 +101,11 @@ int no_printk(const char *fmt, ...)
extern asmlinkage __printf(1, 2)
void early_printk(const char *fmt, ...);
void early_vprintk(const char *fmt, va_list ap);
+extern void printk_kill(void);
#else
static inline __printf(1, 2) __cold
void early_printk(const char *s, ...) { }
+static inline void printk_kill(void) { }
#endif
#ifdef CONFIG_PRINTK
@@ -137,7 +139,6 @@ extern int __printk_ratelimit(const char *func);
#define printk_ratelimit() __printk_ratelimit(__func__)
extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
unsigned int interval_msec);
-
extern int printk_delay_msec;
extern int dmesg_restrict;
extern int kptr_restrict;
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 4039407..5b6d5b2 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -230,8 +230,13 @@ unsigned long radix_tree_next_hole(struct radix_tree_root *root,
unsigned long index, unsigned long max_scan);
unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
unsigned long index, unsigned long max_scan);
+#ifndef CONFIG_PREEMPT_RT_FULL
int radix_tree_preload(gfp_t gfp_mask);
int radix_tree_maybe_preload(gfp_t gfp_mask);
+#else
+static inline int radix_tree_preload(gfp_t gm) { return 0; }
+static inline int radix_tree_maybe_preload(gfp_t gfp_mask) { return 0; }
+#endif
void radix_tree_init(void);
void *radix_tree_tag_set(struct radix_tree_root *root,
unsigned long index, unsigned int tag);
@@ -256,7 +261,7 @@ unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item);
static inline void radix_tree_preload_end(void)
{
- preempt_enable();
+ preempt_enable_nort();
}
/**
diff --git a/include/linux/random.h b/include/linux/random.h
index bf9085e..de4894a 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -12,7 +12,7 @@
extern void add_device_randomness(const void *, unsigned int);
extern void add_input_randomness(unsigned int type, unsigned int code,
unsigned int value);
-extern void add_interrupt_randomness(int irq, int irq_flags);
+extern void add_interrupt_randomness(int irq, int irq_flags, __u64 ip);
extern void get_random_bytes(void *buf, int nbytes);
extern void get_random_bytes_arch(void *buf, int nbytes);
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index f1f1bc3..8b2693d 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -128,6 +128,9 @@ extern void call_rcu(struct rcu_head *head,
#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
+#ifdef CONFIG_PREEMPT_RT_FULL
+#define call_rcu_bh call_rcu
+#else
/**
* call_rcu_bh() - Queue an RCU for invocation after a quicker grace period.
* @head: structure to be used for queueing the RCU updates.
@@ -151,6 +154,7 @@ extern void call_rcu(struct rcu_head *head,
*/
extern void call_rcu_bh(struct rcu_head *head,
void (*func)(struct rcu_head *head));
+#endif
/**
* call_rcu_sched() - Queue an RCU for invocation after sched grace period.
@@ -190,6 +194,11 @@ void synchronize_rcu(void);
* types of kernel builds, the rcu_read_lock() nesting depth is unknowable.
*/
#define rcu_preempt_depth() (current->rcu_read_lock_nesting)
+#ifndef CONFIG_PREEMPT_RT_FULL
+#define sched_rcu_preempt_depth() rcu_preempt_depth()
+#else
+static inline int sched_rcu_preempt_depth(void) { return 0; }
+#endif
#else /* #ifdef CONFIG_PREEMPT_RCU */
@@ -213,6 +222,8 @@ static inline int rcu_preempt_depth(void)
return 0;
}
+#define sched_rcu_preempt_depth() rcu_preempt_depth()
+
#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
/* Internal to kernel */
@@ -362,7 +373,14 @@ static inline int rcu_read_lock_held(void)
* rcu_read_lock_bh_held() is defined out of line to avoid #include-file
* hell.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline int rcu_read_lock_bh_held(void)
+{
+ return rcu_read_lock_held();
+}
+#else
extern int rcu_read_lock_bh_held(void);
+#endif
/**
* rcu_read_lock_sched_held() - might we be in RCU-sched read-side critical section?
@@ -819,10 +837,14 @@ static inline void rcu_read_unlock(void)
static inline void rcu_read_lock_bh(void)
{
local_bh_disable();
+#ifdef CONFIG_PREEMPT_RT_FULL
+ rcu_read_lock();
+#else
__acquire(RCU_BH);
rcu_lock_acquire(&rcu_bh_lock_map);
rcu_lockdep_assert(!rcu_is_cpu_idle(),
"rcu_read_lock_bh() used illegally while idle");
+#endif
}
/*
@@ -832,10 +854,14 @@ static inline void rcu_read_lock_bh(void)
*/
static inline void rcu_read_unlock_bh(void)
{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ rcu_read_unlock();
+#else
rcu_lockdep_assert(!rcu_is_cpu_idle(),
"rcu_read_unlock_bh() used illegally while idle");
rcu_lock_release(&rcu_bh_lock_map);
__release(RCU_BH);
+#endif
local_bh_enable();
}
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 226169d..91333de 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -44,7 +44,11 @@ static inline void rcu_virt_note_context_switch(int cpu)
rcu_note_context_switch(cpu);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define synchronize_rcu_bh synchronize_rcu
+#else
extern void synchronize_rcu_bh(void);
+#endif
extern void synchronize_sched_expedited(void);
extern void synchronize_rcu_expedited(void);
@@ -72,17 +76,19 @@ static inline void synchronize_rcu_bh_expedited(void)
}
extern void rcu_barrier(void);
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define rcu_barrier_bh rcu_barrier
+#else
extern void rcu_barrier_bh(void);
+#endif
extern void rcu_barrier_sched(void);
extern unsigned long rcutorture_testseq;
extern unsigned long rcutorture_vernum;
extern long rcu_batches_completed(void);
-extern long rcu_batches_completed_bh(void);
extern long rcu_batches_completed_sched(void);
extern void rcu_force_quiescent_state(void);
-extern void rcu_bh_force_quiescent_state(void);
extern void rcu_sched_force_quiescent_state(void);
extern void exit_rcu(void);
@@ -90,4 +96,12 @@ extern void exit_rcu(void);
extern void rcu_scheduler_starting(void);
extern int rcu_scheduler_active __read_mostly;
+#ifndef CONFIG_PREEMPT_RT_FULL
+extern void rcu_bh_force_quiescent_state(void);
+extern long rcu_batches_completed_bh(void);
+#else
+# define rcu_bh_force_quiescent_state rcu_force_quiescent_state
+# define rcu_batches_completed_bh rcu_batches_completed
+#endif
+
#endif /* __LINUX_RCUTREE_H */
diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h
index de17134..fa18682 100644
--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -14,10 +14,14 @@
#include <linux/linkage.h>
#include <linux/plist.h>
-#include <linux/spinlock_types.h>
+#include <linux/spinlock_types_raw.h>
extern int max_lock_depth; /* for sysctl */
+#ifdef CONFIG_DEBUG_MUTEXES
+#include <linux/debug_locks.h>
+#endif
+
/**
* The rt_mutex structure
*
@@ -29,9 +33,10 @@ struct rt_mutex {
raw_spinlock_t wait_lock;
struct plist_head wait_list;
struct task_struct *owner;
-#ifdef CONFIG_DEBUG_RT_MUTEXES
int save_state;
- const char *name, *file;
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+ const char *file;
+ const char *name;
int line;
void *magic;
#endif
@@ -56,19 +61,39 @@ struct hrtimer_sleeper;
#ifdef CONFIG_DEBUG_RT_MUTEXES
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
, .name = #mutexname, .file = __FILE__, .line = __LINE__
-# define rt_mutex_init(mutex) __rt_mutex_init(mutex, __func__)
+
+# define rt_mutex_init(mutex) \
+ do { \
+ raw_spin_lock_init(&(mutex)->wait_lock); \
+ __rt_mutex_init(mutex, #mutex); \
+ } while (0)
+
extern void rt_mutex_debug_task_free(struct task_struct *tsk);
#else
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
-# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL)
+
+# define rt_mutex_init(mutex) \
+ do { \
+ raw_spin_lock_init(&(mutex)->wait_lock); \
+ __rt_mutex_init(mutex, #mutex); \
+ } while (0)
+
# define rt_mutex_debug_task_free(t) do { } while (0)
#endif
-#define __RT_MUTEX_INITIALIZER(mutexname) \
- { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
+#define __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \
+ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
, .wait_list = PLIST_HEAD_INIT(mutexname.wait_list) \
, .owner = NULL \
- __DEBUG_RT_MUTEX_INITIALIZER(mutexname)}
+ __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
+
+
+#define __RT_MUTEX_INITIALIZER(mutexname) \
+ { __RT_MUTEX_INITIALIZER_PLAIN(mutexname) }
+
+#define __RT_MUTEX_INITIALIZER_SAVE_STATE(mutexname) \
+ { __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \
+ , .save_state = 1 }
#define DEFINE_RT_MUTEX(mutexname) \
struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
@@ -90,6 +115,7 @@ extern void rt_mutex_destroy(struct rt_mutex *lock);
extern void rt_mutex_lock(struct rt_mutex *lock);
extern int rt_mutex_lock_interruptible(struct rt_mutex *lock,
int detect_deadlock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock, int detect_deadlock);
extern int rt_mutex_timed_lock(struct rt_mutex *lock,
struct hrtimer_sleeper *timeout,
int detect_deadlock);
diff --git a/include/linux/rwlock_rt.h b/include/linux/rwlock_rt.h
new file mode 100644
index 0000000..49ed2d4
--- /dev/null
+++ b/include/linux/rwlock_rt.h
@@ -0,0 +1,99 @@
+#ifndef __LINUX_RWLOCK_RT_H
+#define __LINUX_RWLOCK_RT_H
+
+#ifndef __LINUX_SPINLOCK_H
+#error Do not include directly. Use spinlock.h
+#endif
+
+#define rwlock_init(rwl) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ rt_mutex_init(&(rwl)->lock); \
+ __rt_rwlock_init(rwl, #rwl, &__key); \
+} while (0)
+
+extern void __lockfunc rt_write_lock(rwlock_t *rwlock);
+extern void __lockfunc rt_read_lock(rwlock_t *rwlock);
+extern int __lockfunc rt_write_trylock(rwlock_t *rwlock);
+extern int __lockfunc rt_write_trylock_irqsave(rwlock_t *trylock, unsigned long *flags);
+extern int __lockfunc rt_read_trylock(rwlock_t *rwlock);
+extern void __lockfunc rt_write_unlock(rwlock_t *rwlock);
+extern void __lockfunc rt_read_unlock(rwlock_t *rwlock);
+extern unsigned long __lockfunc rt_write_lock_irqsave(rwlock_t *rwlock);
+extern unsigned long __lockfunc rt_read_lock_irqsave(rwlock_t *rwlock);
+extern void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key);
+
+#define read_trylock(lock) __cond_lock(lock, rt_read_trylock(lock))
+#define write_trylock(lock) __cond_lock(lock, rt_write_trylock(lock))
+
+#define write_trylock_irqsave(lock, flags) \
+ __cond_lock(lock, rt_write_trylock_irqsave(lock, &flags))
+
+#define read_lock_irqsave(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = rt_read_lock_irqsave(lock); \
+ } while (0)
+
+#define write_lock_irqsave(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = rt_write_lock_irqsave(lock); \
+ } while (0)
+
+#define read_lock(lock) rt_read_lock(lock)
+
+#define read_lock_bh(lock) \
+ do { \
+ local_bh_disable(); \
+ rt_read_lock(lock); \
+ } while (0)
+
+#define read_lock_irq(lock) read_lock(lock)
+
+#define write_lock(lock) rt_write_lock(lock)
+
+#define write_lock_bh(lock) \
+ do { \
+ local_bh_disable(); \
+ rt_write_lock(lock); \
+ } while (0)
+
+#define write_lock_irq(lock) write_lock(lock)
+
+#define read_unlock(lock) rt_read_unlock(lock)
+
+#define read_unlock_bh(lock) \
+ do { \
+ rt_read_unlock(lock); \
+ local_bh_enable(); \
+ } while (0)
+
+#define read_unlock_irq(lock) read_unlock(lock)
+
+#define write_unlock(lock) rt_write_unlock(lock)
+
+#define write_unlock_bh(lock) \
+ do { \
+ rt_write_unlock(lock); \
+ local_bh_enable(); \
+ } while (0)
+
+#define write_unlock_irq(lock) write_unlock(lock)
+
+#define read_unlock_irqrestore(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ (void) flags; \
+ rt_read_unlock(lock); \
+ } while (0)
+
+#define write_unlock_irqrestore(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ (void) flags; \
+ rt_write_unlock(lock); \
+ } while (0)
+
+#endif
diff --git a/include/linux/rwlock_types.h b/include/linux/rwlock_types.h
index cc0072e..d0da966 100644
--- a/include/linux/rwlock_types.h
+++ b/include/linux/rwlock_types.h
@@ -1,6 +1,10 @@
#ifndef __LINUX_RWLOCK_TYPES_H
#define __LINUX_RWLOCK_TYPES_H
+#if !defined(__LINUX_SPINLOCK_TYPES_H)
+# error "Do not include directly, include spinlock_types.h"
+#endif
+
/*
* include/linux/rwlock_types.h - generic rwlock type definitions
* and initializers
@@ -43,6 +47,7 @@ typedef struct {
RW_DEP_MAP_INIT(lockname) }
#endif
-#define DEFINE_RWLOCK(x) rwlock_t x = __RW_LOCK_UNLOCKED(x)
+#define DEFINE_RWLOCK(name) \
+ rwlock_t name __cacheline_aligned_in_smp = __RW_LOCK_UNLOCKED(name)
#endif /* __LINUX_RWLOCK_TYPES_H */
diff --git a/include/linux/rwlock_types_rt.h b/include/linux/rwlock_types_rt.h
new file mode 100644
index 0000000..b138321
--- /dev/null
+++ b/include/linux/rwlock_types_rt.h
@@ -0,0 +1,33 @@
+#ifndef __LINUX_RWLOCK_TYPES_RT_H
+#define __LINUX_RWLOCK_TYPES_RT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+/*
+ * rwlocks - rtmutex which allows single reader recursion
+ */
+typedef struct {
+ struct rt_mutex lock;
+ int read_depth;
+ unsigned int break_lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+} rwlock_t;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define RW_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }
+#else
+# define RW_DEP_MAP_INIT(lockname)
+#endif
+
+#define __RW_LOCK_UNLOCKED(name) \
+ { .lock = __RT_MUTEX_INITIALIZER_SAVE_STATE(name.lock), \
+ RW_DEP_MAP_INIT(name) }
+
+#define DEFINE_RWLOCK(name) \
+ rwlock_t name __cacheline_aligned_in_smp = __RW_LOCK_UNLOCKED(name)
+
+#endif
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 0616ffe..0ad6070 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -16,6 +16,10 @@
#include <linux/atomic.h>
+#ifdef CONFIG_PREEMPT_RT_FULL
+#include <linux/rwsem_rt.h>
+#else /* PREEMPT_RT_FULL */
+
struct rw_semaphore;
#ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
@@ -149,4 +153,6 @@ extern void up_read_non_owner(struct rw_semaphore *sem);
# define up_read_non_owner(sem) up_read(sem)
#endif
+#endif /* !PREEMPT_RT_FULL */
+
#endif /* _LINUX_RWSEM_H */
diff --git a/include/linux/rwsem_rt.h b/include/linux/rwsem_rt.h
new file mode 100644
index 0000000..e94d945
--- /dev/null
+++ b/include/linux/rwsem_rt.h
@@ -0,0 +1,128 @@
+#ifndef _LINUX_RWSEM_RT_H
+#define _LINUX_RWSEM_RT_H
+
+#ifndef _LINUX_RWSEM_H
+#error "Include rwsem.h"
+#endif
+
+/*
+ * RW-semaphores are a spinlock plus a reader-depth count.
+ *
+ * Note that the semantics are different from the usual
+ * Linux rw-sems, in PREEMPT_RT mode we do not allow
+ * multiple readers to hold the lock at once, we only allow
+ * a read-lock owner to read-lock recursively. This is
+ * better for latency, makes the implementation inherently
+ * fair and makes it simpler as well.
+ */
+
+#include <linux/rtmutex.h>
+
+struct rw_semaphore {
+ struct rt_mutex lock;
+ int read_depth;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+};
+
+#define __RWSEM_INITIALIZER(name) \
+ { .lock = __RT_MUTEX_INITIALIZER(name.lock), \
+ RW_DEP_MAP_INIT(name) }
+
+#define DECLARE_RWSEM(lockname) \
+ struct rw_semaphore lockname = __RWSEM_INITIALIZER(lockname)
+
+extern void __rt_rwsem_init(struct rw_semaphore *rwsem, const char *name,
+ struct lock_class_key *key);
+
+#define __rt_init_rwsem(sem, name, key) \
+ do { \
+ rt_mutex_init(&(sem)->lock); \
+ __rt_rwsem_init((sem), (name), (key));\
+ } while (0)
+
+#define __init_rwsem(sem, name, key) __rt_init_rwsem(sem, name, key)
+
+# define rt_init_rwsem(sem) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ __rt_init_rwsem((sem), #sem, &__key); \
+} while (0)
+
+extern void rt_down_write(struct rw_semaphore *rwsem);
+extern void rt_down_read_nested(struct rw_semaphore *rwsem, int subclass);
+extern void rt_down_write_nested(struct rw_semaphore *rwsem, int subclass);
+extern void rt_down_write_nested_lock(struct rw_semaphore *rwsem,
+ struct lockdep_map *nest);
+extern void rt_down_read(struct rw_semaphore *rwsem);
+extern int rt_down_write_trylock(struct rw_semaphore *rwsem);
+extern int rt_down_read_trylock(struct rw_semaphore *rwsem);
+extern void rt_up_read(struct rw_semaphore *rwsem);
+extern void rt_up_write(struct rw_semaphore *rwsem);
+extern void rt_downgrade_write(struct rw_semaphore *rwsem);
+
+#define init_rwsem(sem) rt_init_rwsem(sem)
+#define rwsem_is_locked(s) rt_mutex_is_locked(&(s)->lock)
+
+static inline void down_read(struct rw_semaphore *sem)
+{
+ rt_down_read(sem);
+}
+
+static inline int down_read_trylock(struct rw_semaphore *sem)
+{
+ return rt_down_read_trylock(sem);
+}
+
+static inline void down_write(struct rw_semaphore *sem)
+{
+ rt_down_write(sem);
+}
+
+static inline int down_write_trylock(struct rw_semaphore *sem)
+{
+ return rt_down_write_trylock(sem);
+}
+
+static inline void up_read(struct rw_semaphore *sem)
+{
+ rt_up_read(sem);
+}
+
+static inline void up_write(struct rw_semaphore *sem)
+{
+ rt_up_write(sem);
+}
+
+static inline void downgrade_write(struct rw_semaphore *sem)
+{
+ rt_downgrade_write(sem);
+}
+
+static inline void down_read_nested(struct rw_semaphore *sem, int subclass)
+{
+ return rt_down_read_nested(sem, subclass);
+}
+
+static inline void down_write_nested(struct rw_semaphore *sem, int subclass)
+{
+ rt_down_write_nested(sem, subclass);
+}
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static inline void down_write_nest_lock(struct rw_semaphore *sem,
+ struct rw_semaphore *nest_lock)
+{
+ rt_down_write_nested_lock(sem, &nest_lock->dep_map);
+}
+
+#else
+
+static inline void down_write_nest_lock(struct rw_semaphore *sem,
+ struct rw_semaphore *nest_lock)
+{
+ rt_down_write_nested_lock(sem, NULL);
+}
+#endif
+#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index b1e963e..625a41f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -23,6 +23,7 @@ struct sched_param {
#include <linux/nodemask.h>
#include <linux/mm_types.h>
+#include <asm/kmap_types.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/cputime.h>
@@ -52,6 +53,7 @@ struct sched_param {
#include <linux/llist.h>
#include <linux/uidgid.h>
#include <linux/gfp.h>
+#include <linux/hardirq.h>
#include <asm/processor.h>
@@ -165,11 +167,8 @@ extern char ___assert_task_state[1 - 2*!!(
TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
__TASK_TRACED)
-#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
#define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
#define task_is_dead(task) ((task)->exit_state != 0)
-#define task_is_stopped_or_traced(task) \
- ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
#define task_contributes_to_load(task) \
((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
(task->flags & PF_FROZEN) == 0)
@@ -1022,6 +1021,7 @@ enum perf_event_task_context {
struct task_struct {
volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
+ volatile long saved_state; /* saved state for "spinlock sleepers" */
void *stack;
atomic_t usage;
unsigned int flags; /* per process flags, defined below */
@@ -1064,6 +1064,12 @@ struct task_struct {
#endif
unsigned int policy;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ int migrate_disable;
+# ifdef CONFIG_SCHED_DEBUG
+ int migrate_disable_atomic;
+# endif
+#endif
int nr_cpus_allowed;
cpumask_t cpus_allowed;
@@ -1159,7 +1165,8 @@ struct task_struct {
struct cputime prev_cputime;
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
- seqlock_t vtime_seqlock;
+ raw_spinlock_t vtime_lock;
+ seqcount_t vtime_seq;
unsigned long long vtime_snap;
enum {
VTIME_SLEEPING = 0,
@@ -1175,6 +1182,9 @@ struct task_struct {
struct task_cputime cputime_expires;
struct list_head cpu_timers[3];
+#ifdef CONFIG_PREEMPT_RT_BASE
+ struct task_struct *posix_timer_list;
+#endif
/* process credentials */
const struct cred __rcu *real_cred; /* objective and real subjective task
@@ -1206,10 +1216,15 @@ struct task_struct {
/* signal handlers */
struct signal_struct *signal;
struct sighand_struct *sighand;
+ struct sigqueue *sigqueue_cache;
sigset_t blocked, real_blocked;
sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
struct sigpending pending;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /* TODO: move me into ->restart_block ? */
+ struct siginfo forced_info;
+#endif
unsigned long sas_ss_sp;
size_t sas_ss_size;
@@ -1246,6 +1261,9 @@ struct task_struct {
/* mutex deadlock detection */
struct mutex_waiter *blocked_on;
#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+ int pagefault_disabled;
+#endif
#ifdef CONFIG_TRACE_IRQFLAGS
unsigned int irq_events;
unsigned long hardirq_enable_ip;
@@ -1321,6 +1339,9 @@ struct task_struct {
struct mutex perf_event_mutex;
struct list_head perf_event_list;
#endif
+#ifdef CONFIG_DEBUG_PREEMPT
+ unsigned long preempt_disable_ip;
+#endif
#ifdef CONFIG_NUMA
struct mempolicy *mempolicy; /* Protected by alloc_lock */
short il_next;
@@ -1388,6 +1409,12 @@ struct task_struct {
unsigned long trace;
/* bitmask and counter of trace recursion */
unsigned long trace_recursion;
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ u64 preempt_timestamp_hist;
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ long timer_offset;
+#endif
+#endif
#endif /* CONFIG_TRACING */
#ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
struct memcg_batch_info {
@@ -1411,11 +1438,19 @@ struct task_struct {
unsigned int sequential_io;
unsigned int sequential_io_avg;
#endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+ struct rcu_head put_rcu;
+ int softirq_nestcnt;
+ unsigned int softirqs_raised;
+#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+# if defined CONFIG_HIGHMEM || defined CONFIG_X86_32
+ int kmap_idx;
+ pte_t kmap_pte[KM_TYPE_NR];
+# endif
+#endif
};
-/* Future-safe accessor for struct task_struct's cpus_allowed. */
-#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
-
#ifdef CONFIG_NUMA_BALANCING
extern void task_numa_fault(int node, int pages, bool migrated);
extern void set_numabalancing_state(bool enabled);
@@ -1428,6 +1463,17 @@ static inline void set_numabalancing_state(bool enabled)
}
#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline bool cur_pf_disabled(void) { return current->pagefault_disabled; }
+#else
+static inline bool cur_pf_disabled(void) { return false; }
+#endif
+
+static inline bool pagefault_disabled(void)
+{
+ return in_atomic() || cur_pf_disabled();
+}
+
static inline struct pid *task_pid(struct task_struct *task)
{
return task->pids[PIDTYPE_PID].pid;
@@ -1563,6 +1609,15 @@ extern struct pid *cad_pid;
extern void free_task(struct task_struct *tsk);
#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
+#ifdef CONFIG_PREEMPT_RT_BASE
+extern void __put_task_struct_cb(struct rcu_head *rhp);
+
+static inline void put_task_struct(struct task_struct *t)
+{
+ if (atomic_dec_and_test(&t->usage))
+ call_rcu(&t->put_rcu, __put_task_struct_cb);
+}
+#else
extern void __put_task_struct(struct task_struct *t);
static inline void put_task_struct(struct task_struct *t)
@@ -1570,6 +1625,7 @@ static inline void put_task_struct(struct task_struct *t)
if (atomic_dec_and_test(&t->usage))
__put_task_struct(t);
}
+#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
extern void task_cputime(struct task_struct *t,
@@ -1608,6 +1664,7 @@ extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut,
/*
* Per process flags
*/
+#define PF_IN_SOFTIRQ 0x00000001 /* Task is serving softirq */
#define PF_EXITING 0x00000004 /* getting shut down */
#define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
#define PF_VCPU 0x00000010 /* I'm a virtual CPU */
@@ -1753,6 +1810,10 @@ extern void do_set_cpus_allowed(struct task_struct *p,
extern int set_cpus_allowed_ptr(struct task_struct *p,
const struct cpumask *new_mask);
+int migrate_me(void);
+void tell_sched_cpu_down_begin(int cpu);
+void tell_sched_cpu_down_done(int cpu);
+
#else
static inline void do_set_cpus_allowed(struct task_struct *p,
const struct cpumask *new_mask)
@@ -1765,6 +1826,9 @@ static inline int set_cpus_allowed_ptr(struct task_struct *p,
return -EINVAL;
return 0;
}
+static inline int migrate_me(void) { return 0; }
+static inline void tell_sched_cpu_down_begin(int cpu) { }
+static inline void tell_sched_cpu_down_done(int cpu) { }
#endif
#ifdef CONFIG_NO_HZ_COMMON
@@ -1972,6 +2036,7 @@ extern void xtime_update(unsigned long ticks);
extern int wake_up_state(struct task_struct *tsk, unsigned int state);
extern int wake_up_process(struct task_struct *tsk);
+extern int wake_up_lock_sleeper(struct task_struct * tsk);
extern void wake_up_new_task(struct task_struct *tsk);
#ifdef CONFIG_SMP
extern void kick_process(struct task_struct *tsk);
@@ -2086,12 +2151,24 @@ extern struct mm_struct * mm_alloc(void);
/* mmdrop drops the mm and the page tables */
extern void __mmdrop(struct mm_struct *);
+
static inline void mmdrop(struct mm_struct * mm)
{
if (unlikely(atomic_dec_and_test(&mm->mm_count)))
__mmdrop(mm);
}
+#ifdef CONFIG_PREEMPT_RT_BASE
+extern void __mmdrop_delayed(struct rcu_head *rhp);
+static inline void mmdrop_delayed(struct mm_struct *mm)
+{
+ if (atomic_dec_and_test(&mm->mm_count))
+ call_rcu(&mm->delayed_drop, __mmdrop_delayed);
+}
+#else
+# define mmdrop_delayed(mm) mmdrop(mm)
+#endif
+
/* mmput gets rid of the mappings and all user-space */
extern void mmput(struct mm_struct *);
/* Grab a reference to a task's mm, if it is not already going away */
@@ -2374,6 +2451,52 @@ static inline int test_tsk_need_resched(struct task_struct *tsk)
return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
}
+#ifdef CONFIG_PREEMPT_LAZY
+static inline void set_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+ set_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+ clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int test_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+ return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY));
+}
+
+static inline int need_resched_lazy(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int need_resched_now(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+static inline int need_resched(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED) ||
+ test_thread_flag(TIF_NEED_RESCHED_LAZY);
+}
+#else
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk) { }
+static inline int need_resched_lazy(void) { return 0; }
+
+static inline int need_resched_now(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+static inline int need_resched(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED);
+}
+#endif
+
static inline int restart_syscall(void)
{
set_tsk_thread_flag(current, TIF_SIGPENDING);
@@ -2405,9 +2528,49 @@ static inline int signal_pending_state(long state, struct task_struct *p)
return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
}
-static inline int need_resched(void)
+static inline bool __task_is_stopped_or_traced(struct task_struct *task)
+{
+ if (task->state & (__TASK_STOPPED | __TASK_TRACED))
+ return true;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (task->saved_state & (__TASK_STOPPED | __TASK_TRACED))
+ return true;
+#endif
+ return false;
+}
+
+static inline bool task_is_stopped_or_traced(struct task_struct *task)
+{
+ bool traced_stopped;
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+ traced_stopped = __task_is_stopped_or_traced(task);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+#else
+ traced_stopped = __task_is_stopped_or_traced(task);
+#endif
+ return traced_stopped;
+}
+
+static inline bool task_is_traced(struct task_struct *task)
{
- return unlikely(test_thread_flag(TIF_NEED_RESCHED));
+ bool traced = false;
+
+ if (task->state & __TASK_TRACED)
+ return true;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /* in case the task is sleeping on tasklist_lock */
+ raw_spin_lock_irq(&task->pi_lock);
+ if (task->state & __TASK_TRACED)
+ traced = true;
+ else if (task->saved_state & __TASK_TRACED)
+ traced = true;
+ raw_spin_unlock_irq(&task->pi_lock);
+#endif
+ return traced;
}
/*
@@ -2426,7 +2589,7 @@ extern int _cond_resched(void);
extern int __cond_resched_lock(spinlock_t *lock);
-#ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_PREEMPT_COUNT) && !defined(CONFIG_PREEMPT_RT_FULL)
#define PREEMPT_LOCK_OFFSET PREEMPT_OFFSET
#else
#define PREEMPT_LOCK_OFFSET 0
@@ -2437,12 +2600,16 @@ extern int __cond_resched_lock(spinlock_t *lock);
__cond_resched_lock(lock); \
})
+#ifndef CONFIG_PREEMPT_RT_FULL
extern int __cond_resched_softirq(void);
#define cond_resched_softirq() ({ \
__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
__cond_resched_softirq(); \
})
+#else
+# define cond_resched_softirq() cond_resched()
+#endif
static inline void cond_resched_rcu(void)
{
@@ -2628,6 +2795,26 @@ static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
#endif /* CONFIG_SMP */
+static inline int __migrate_disabled(struct task_struct *p)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ return p->migrate_disable;
+#else
+ return 0;
+#endif
+}
+
+/* Future-safe accessor for struct task_struct's cpus_allowed. */
+static inline const struct cpumask *tsk_cpus_allowed(struct task_struct *p)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (p->migrate_disable)
+ return cpumask_of(task_cpu(p));
+#endif
+
+ return &p->cpus_allowed;
+}
+
extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
diff --git a/include/linux/sched/rt.h b/include/linux/sched/rt.h
index 440434d..4d54d6c 100644
--- a/include/linux/sched/rt.h
+++ b/include/linux/sched/rt.h
@@ -35,6 +35,7 @@ static inline int rt_task(struct task_struct *p)
#ifdef CONFIG_RT_MUTEXES
extern int rt_mutex_getprio(struct task_struct *p);
extern void rt_mutex_setprio(struct task_struct *p, int prio);
+extern int rt_mutex_check_prio(struct task_struct *task, int newprio);
extern void rt_mutex_adjust_pi(struct task_struct *p);
static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
{
@@ -45,6 +46,10 @@ static inline int rt_mutex_getprio(struct task_struct *p)
{
return p->normal_prio;
}
+static inline int rt_mutex_check_prio(struct task_struct *task, int newprio)
+{
+ return 0;
+}
# define rt_mutex_adjust_pi(p) do { } while (0)
static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
{
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 21a2093..019a936 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -152,18 +152,30 @@ static inline int read_seqcount_retry(const seqcount_t *s, unsigned start)
* Sequence counter only version assumes that callers are using their
* own mutexing.
*/
-static inline void write_seqcount_begin(seqcount_t *s)
+static inline void __write_seqcount_begin(seqcount_t *s)
{
s->sequence++;
smp_wmb();
}
-static inline void write_seqcount_end(seqcount_t *s)
+static inline void write_seqcount_begin(seqcount_t *s)
+{
+ preempt_disable_rt();
+ __write_seqcount_begin(s);
+}
+
+static inline void __write_seqcount_end(seqcount_t *s)
{
smp_wmb();
s->sequence++;
}
+static inline void write_seqcount_end(seqcount_t *s)
+{
+ __write_seqcount_end(s);
+ preempt_enable_rt();
+}
+
/**
* write_seqcount_barrier - invalidate in-progress read-side seq operations
* @s: pointer to seqcount_t
@@ -204,10 +216,32 @@ typedef struct {
/*
* Read side functions for starting and finalizing a read side section.
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
static inline unsigned read_seqbegin(const seqlock_t *sl)
{
return read_seqcount_begin(&sl->seqcount);
}
+#else
+/*
+ * Starvation safe read side for RT
+ */
+static inline unsigned read_seqbegin(seqlock_t *sl)
+{
+ unsigned ret;
+
+repeat:
+ ret = ACCESS_ONCE(sl->seqcount.sequence);
+ if (unlikely(ret & 1)) {
+ /*
+ * Take the lock and let the writer proceed (i.e. evtl
+ * boost it), otherwise we could loop here forever.
+ */
+ spin_unlock_wait(&sl->lock);
+ goto repeat;
+ }
+ return ret;
+}
+#endif
static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start)
{
@@ -222,36 +256,36 @@ static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start)
static inline void write_seqlock(seqlock_t *sl)
{
spin_lock(&sl->lock);
- write_seqcount_begin(&sl->seqcount);
+ __write_seqcount_begin(&sl->seqcount);
}
static inline void write_sequnlock(seqlock_t *sl)
{
- write_seqcount_end(&sl->seqcount);
+ __write_seqcount_end(&sl->seqcount);
spin_unlock(&sl->lock);
}
static inline void write_seqlock_bh(seqlock_t *sl)
{
spin_lock_bh(&sl->lock);
- write_seqcount_begin(&sl->seqcount);
+ __write_seqcount_begin(&sl->seqcount);
}
static inline void write_sequnlock_bh(seqlock_t *sl)
{
- write_seqcount_end(&sl->seqcount);
+ __write_seqcount_end(&sl->seqcount);
spin_unlock_bh(&sl->lock);
}
static inline void write_seqlock_irq(seqlock_t *sl)
{
spin_lock_irq(&sl->lock);
- write_seqcount_begin(&sl->seqcount);
+ __write_seqcount_begin(&sl->seqcount);
}
static inline void write_sequnlock_irq(seqlock_t *sl)
{
- write_seqcount_end(&sl->seqcount);
+ __write_seqcount_end(&sl->seqcount);
spin_unlock_irq(&sl->lock);
}
@@ -260,7 +294,7 @@ static inline unsigned long __write_seqlock_irqsave(seqlock_t *sl)
unsigned long flags;
spin_lock_irqsave(&sl->lock, flags);
- write_seqcount_begin(&sl->seqcount);
+ __write_seqcount_begin(&sl->seqcount);
return flags;
}
@@ -270,7 +304,7 @@ static inline unsigned long __write_seqlock_irqsave(seqlock_t *sl)
static inline void
write_sequnlock_irqrestore(seqlock_t *sl, unsigned long flags)
{
- write_seqcount_end(&sl->seqcount);
+ __write_seqcount_end(&sl->seqcount);
spin_unlock_irqrestore(&sl->lock, flags);
}
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 2ac423b..1414eb2 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -226,6 +226,7 @@ static inline void init_sigpending(struct sigpending *sig)
}
extern void flush_sigqueue(struct sigpending *queue);
+extern void flush_task_sigqueue(struct task_struct *tsk);
/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
static inline int valid_signal(unsigned long sig)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 7521bf4..7406b93 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -133,6 +133,7 @@ struct sk_buff_head {
__u32 qlen;
spinlock_t lock;
+ raw_spinlock_t raw_lock;
};
struct sk_buff;
@@ -1075,6 +1076,12 @@ static inline void skb_queue_head_init(struct sk_buff_head *list)
__skb_queue_head_init(list);
}
+static inline void skb_queue_head_init_raw(struct sk_buff_head *list)
+{
+ raw_spin_lock_init(&list->raw_lock);
+ __skb_queue_head_init(list);
+}
+
static inline void skb_queue_head_init_class(struct sk_buff_head *list,
struct lock_class_key *class)
{
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 731f523..e05b694 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -188,6 +188,9 @@ static inline void __smp_call_function_single(int cpuid,
#define get_cpu() ({ preempt_disable(); smp_processor_id(); })
#define put_cpu() preempt_enable()
+#define get_cpu_light() ({ migrate_disable(); smp_processor_id(); })
+#define put_cpu_light() migrate_enable()
+
/*
* Callback to arch code if there's nosmp or maxcpus=0 on the
* boot command line:
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 75f3494..a124f92 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -262,7 +262,11 @@ static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)
#define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))
/* Include rwlock functions */
-#include <linux/rwlock.h>
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/rwlock_rt.h>
+#else
+# include <linux/rwlock.h>
+#endif
/*
* Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
@@ -273,6 +277,10 @@ static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)
# include <linux/spinlock_api_up.h>
#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/spinlock_rt.h>
+#else /* PREEMPT_RT_FULL */
+
/*
* Map the spin_lock functions to the raw variants for PREEMPT_RT=n
*/
@@ -402,4 +410,6 @@ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
#define atomic_dec_and_lock(atomic, lock) \
__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
+#endif /* !PREEMPT_RT_FULL */
+
#endif /* __LINUX_SPINLOCK_H */
diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h
index bdb9993..1356078 100644
--- a/include/linux/spinlock_api_smp.h
+++ b/include/linux/spinlock_api_smp.h
@@ -191,6 +191,8 @@ static inline int __raw_spin_trylock_bh(raw_spinlock_t *lock)
return 0;
}
-#include <linux/rwlock_api_smp.h>
+#ifndef CONFIG_PREEMPT_RT_FULL
+# include <linux/rwlock_api_smp.h>
+#endif
#endif /* __LINUX_SPINLOCK_API_SMP_H */
diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h
new file mode 100644
index 0000000..ac6f08b
--- /dev/null
+++ b/include/linux/spinlock_rt.h
@@ -0,0 +1,166 @@
+#ifndef __LINUX_SPINLOCK_RT_H
+#define __LINUX_SPINLOCK_RT_H
+
+#ifndef __LINUX_SPINLOCK_H
+#error Do not include directly. Use spinlock.h
+#endif
+
+#include <linux/bug.h>
+
+extern void
+__rt_spin_lock_init(spinlock_t *lock, char *name, struct lock_class_key *key);
+
+#define spin_lock_init(slock) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ rt_mutex_init(&(slock)->lock); \
+ __rt_spin_lock_init(slock, #slock, &__key); \
+} while (0)
+
+extern void __lockfunc rt_spin_lock(spinlock_t *lock);
+extern unsigned long __lockfunc rt_spin_lock_trace_flags(spinlock_t *lock);
+extern void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass);
+extern void __lockfunc rt_spin_unlock(spinlock_t *lock);
+extern void __lockfunc rt_spin_unlock_after_trylock_in_irq(spinlock_t *lock);
+extern void __lockfunc rt_spin_unlock_wait(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags);
+extern int __lockfunc rt_spin_trylock_bh(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock(spinlock_t *lock);
+extern int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock);
+
+/*
+ * lockdep-less calls, for derived types like rwlock:
+ * (for trylock they can use rt_mutex_trylock() directly.
+ */
+extern void __lockfunc __rt_spin_lock(struct rt_mutex *lock);
+extern void __lockfunc __rt_spin_unlock(struct rt_mutex *lock);
+
+#define spin_lock(lock) \
+ do { \
+ migrate_disable(); \
+ rt_spin_lock(lock); \
+ } while (0)
+
+#define spin_lock_bh(lock) \
+ do { \
+ local_bh_disable(); \
+ migrate_disable(); \
+ rt_spin_lock(lock); \
+ } while (0)
+
+#define spin_lock_irq(lock) spin_lock(lock)
+
+#define spin_do_trylock(lock) __cond_lock(lock, rt_spin_trylock(lock))
+
+#define spin_trylock(lock) \
+({ \
+ int __locked; \
+ migrate_disable(); \
+ __locked = spin_do_trylock(lock); \
+ if (!__locked) \
+ migrate_enable(); \
+ __locked; \
+})
+
+#ifdef CONFIG_LOCKDEP
+# define spin_lock_nested(lock, subclass) \
+ do { \
+ migrate_disable(); \
+ rt_spin_lock_nested(lock, subclass); \
+ } while (0)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ migrate_disable(); \
+ rt_spin_lock_nested(lock, subclass); \
+ } while (0)
+#else
+# define spin_lock_nested(lock, subclass) spin_lock(lock)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ spin_lock(lock); \
+ } while (0)
+#endif
+
+#define spin_lock_irqsave(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ spin_lock(lock); \
+ } while (0)
+
+static inline unsigned long spin_lock_trace_flags(spinlock_t *lock)
+{
+ unsigned long flags = 0;
+#ifdef CONFIG_TRACE_IRQFLAGS
+ flags = rt_spin_lock_trace_flags(lock);
+#else
+ spin_lock(lock); /* lock_local */
+#endif
+ return flags;
+}
+
+/* FIXME: we need rt_spin_lock_nest_lock */
+#define spin_lock_nest_lock(lock, nest_lock) spin_lock_nested(lock, 0)
+
+#define spin_unlock(lock) \
+ do { \
+ rt_spin_unlock(lock); \
+ migrate_enable(); \
+ } while (0)
+
+#define spin_unlock_bh(lock) \
+ do { \
+ rt_spin_unlock(lock); \
+ migrate_enable(); \
+ local_bh_enable(); \
+ } while (0)
+
+#define spin_unlock_irq(lock) spin_unlock(lock)
+
+#define spin_unlock_irqrestore(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ (void) flags; \
+ spin_unlock(lock); \
+ } while (0)
+
+#define spin_trylock_bh(lock) __cond_lock(lock, rt_spin_trylock_bh(lock))
+#define spin_trylock_irq(lock) spin_trylock(lock)
+
+#define spin_trylock_irqsave(lock, flags) \
+ rt_spin_trylock_irqsave(lock, &(flags))
+
+#define spin_unlock_wait(lock) rt_spin_unlock_wait(lock)
+
+#ifdef CONFIG_GENERIC_LOCKBREAK
+# define spin_is_contended(lock) ((lock)->break_lock)
+#else
+# define spin_is_contended(lock) (((void)(lock), 0))
+#endif
+
+static inline int spin_can_lock(spinlock_t *lock)
+{
+ return !rt_mutex_is_locked(&lock->lock);
+}
+
+static inline int spin_is_locked(spinlock_t *lock)
+{
+ return rt_mutex_is_locked(&lock->lock);
+}
+
+static inline void assert_spin_locked(spinlock_t *lock)
+{
+ BUG_ON(!spin_is_locked(lock));
+}
+
+#define atomic_dec_and_lock(atomic, lock) \
+ atomic_dec_and_spin_lock(atomic, lock)
+
+#endif
diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h
index 73548eb..10bac71 100644
--- a/include/linux/spinlock_types.h
+++ b/include/linux/spinlock_types.h
@@ -9,80 +9,15 @@
* Released under the General Public License (GPL).
*/
-#if defined(CONFIG_SMP)
-# include <asm/spinlock_types.h>
-#else
-# include <linux/spinlock_types_up.h>
-#endif
-
-#include <linux/lockdep.h>
-
-typedef struct raw_spinlock {
- arch_spinlock_t raw_lock;
-#ifdef CONFIG_GENERIC_LOCKBREAK
- unsigned int break_lock;
-#endif
-#ifdef CONFIG_DEBUG_SPINLOCK
- unsigned int magic, owner_cpu;
- void *owner;
-#endif
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- struct lockdep_map dep_map;
-#endif
-} raw_spinlock_t;
-
-#define SPINLOCK_MAGIC 0xdead4ead
-
-#define SPINLOCK_OWNER_INIT ((void *)-1L)
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define SPIN_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }
-#else
-# define SPIN_DEP_MAP_INIT(lockname)
-#endif
+#include <linux/spinlock_types_raw.h>
-#ifdef CONFIG_DEBUG_SPINLOCK
-# define SPIN_DEBUG_INIT(lockname) \
- .magic = SPINLOCK_MAGIC, \
- .owner_cpu = -1, \
- .owner = SPINLOCK_OWNER_INIT,
+#ifndef CONFIG_PREEMPT_RT_FULL
+# include <linux/spinlock_types_nort.h>
+# include <linux/rwlock_types.h>
#else
-# define SPIN_DEBUG_INIT(lockname)
+# include <linux/rtmutex.h>
+# include <linux/spinlock_types_rt.h>
+# include <linux/rwlock_types_rt.h>
#endif
-#define __RAW_SPIN_LOCK_INITIALIZER(lockname) \
- { \
- .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \
- SPIN_DEBUG_INIT(lockname) \
- SPIN_DEP_MAP_INIT(lockname) }
-
-#define __RAW_SPIN_LOCK_UNLOCKED(lockname) \
- (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
-
-#define DEFINE_RAW_SPINLOCK(x) raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
-
-typedef struct spinlock {
- union {
- struct raw_spinlock rlock;
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map))
- struct {
- u8 __padding[LOCK_PADSIZE];
- struct lockdep_map dep_map;
- };
-#endif
- };
-} spinlock_t;
-
-#define __SPIN_LOCK_INITIALIZER(lockname) \
- { { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
-
-#define __SPIN_LOCK_UNLOCKED(lockname) \
- (spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
-
-#define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
-
-#include <linux/rwlock_types.h>
-
#endif /* __LINUX_SPINLOCK_TYPES_H */
diff --git a/include/linux/spinlock_types_nort.h b/include/linux/spinlock_types_nort.h
new file mode 100644
index 0000000..f1dac1f
--- /dev/null
+++ b/include/linux/spinlock_types_nort.h
@@ -0,0 +1,33 @@
+#ifndef __LINUX_SPINLOCK_TYPES_NORT_H
+#define __LINUX_SPINLOCK_TYPES_NORT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+/*
+ * The non RT version maps spinlocks to raw_spinlocks
+ */
+typedef struct spinlock {
+ union {
+ struct raw_spinlock rlock;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map))
+ struct {
+ u8 __padding[LOCK_PADSIZE];
+ struct lockdep_map dep_map;
+ };
+#endif
+ };
+} spinlock_t;
+
+#define __SPIN_LOCK_INITIALIZER(lockname) \
+ { { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
+
+#define __SPIN_LOCK_UNLOCKED(lockname) \
+ (spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
+
+#endif
diff --git a/include/linux/spinlock_types_raw.h b/include/linux/spinlock_types_raw.h
new file mode 100644
index 0000000..edffc4d
--- /dev/null
+++ b/include/linux/spinlock_types_raw.h
@@ -0,0 +1,56 @@
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
+#define __LINUX_SPINLOCK_TYPES_RAW_H
+
+#if defined(CONFIG_SMP)
+# include <asm/spinlock_types.h>
+#else
+# include <linux/spinlock_types_up.h>
+#endif
+
+#include <linux/lockdep.h>
+
+typedef struct raw_spinlock {
+ arch_spinlock_t raw_lock;
+#ifdef CONFIG_GENERIC_LOCKBREAK
+ unsigned int break_lock;
+#endif
+#ifdef CONFIG_DEBUG_SPINLOCK
+ unsigned int magic, owner_cpu;
+ void *owner;
+#endif
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+} raw_spinlock_t;
+
+#define SPINLOCK_MAGIC 0xdead4ead
+
+#define SPINLOCK_OWNER_INIT ((void *)-1L)
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define SPIN_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }
+#else
+# define SPIN_DEP_MAP_INIT(lockname)
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define SPIN_DEBUG_INIT(lockname) \
+ .magic = SPINLOCK_MAGIC, \
+ .owner_cpu = -1, \
+ .owner = SPINLOCK_OWNER_INIT,
+#else
+# define SPIN_DEBUG_INIT(lockname)
+#endif
+
+#define __RAW_SPIN_LOCK_INITIALIZER(lockname) \
+ { \
+ .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \
+ SPIN_DEBUG_INIT(lockname) \
+ SPIN_DEP_MAP_INIT(lockname) }
+
+#define __RAW_SPIN_LOCK_UNLOCKED(lockname) \
+ (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_RAW_SPINLOCK(x) raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
+
+#endif
diff --git a/include/linux/spinlock_types_rt.h b/include/linux/spinlock_types_rt.h
new file mode 100644
index 0000000..9fd4319
--- /dev/null
+++ b/include/linux/spinlock_types_rt.h
@@ -0,0 +1,51 @@
+#ifndef __LINUX_SPINLOCK_TYPES_RT_H
+#define __LINUX_SPINLOCK_TYPES_RT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+#include <linux/cache.h>
+
+/*
+ * PREEMPT_RT: spinlocks - an RT mutex plus lock-break field:
+ */
+typedef struct spinlock {
+ struct rt_mutex lock;
+ unsigned int break_lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+} spinlock_t;
+
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+# define __RT_SPIN_INITIALIZER(name) \
+ { \
+ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
+ .save_state = 1, \
+ .file = __FILE__, \
+ .line = __LINE__ , \
+ }
+#else
+# define __RT_SPIN_INITIALIZER(name) \
+ { \
+ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
+ .save_state = 1, \
+ }
+#endif
+
+/*
+.wait_list = PLIST_HEAD_INIT_RAW((name).lock.wait_list, (name).lock.wait_lock)
+*/
+
+#define __SPIN_LOCK_UNLOCKED(name) \
+ { .lock = __RT_SPIN_INITIALIZER(name.lock), \
+ SPIN_DEP_MAP_INIT(name) }
+
+#define __DEFINE_SPINLOCK(name) \
+ spinlock_t name = __SPIN_LOCK_UNLOCKED(name)
+
+#define DEFINE_SPINLOCK(name) \
+ spinlock_t name __cacheline_aligned_in_smp = __SPIN_LOCK_UNLOCKED(name)
+
+#endif
diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index c114614..d5e50dd 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -84,10 +84,10 @@ int init_srcu_struct(struct srcu_struct *sp);
void process_srcu(struct work_struct *work);
-#define __SRCU_STRUCT_INIT(name) \
+#define __SRCU_STRUCT_INIT(name, pcpu_name) \
{ \
.completed = -300, \
- .per_cpu_ref = &name##_srcu_array, \
+ .per_cpu_ref = &pcpu_name, \
.queue_lock = __SPIN_LOCK_UNLOCKED(name.queue_lock), \
.running = false, \
.batch_queue = RCU_BATCH_INIT(name.batch_queue), \
@@ -104,11 +104,12 @@ void process_srcu(struct work_struct *work);
*/
#define DEFINE_SRCU(name) \
static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
- struct srcu_struct name = __SRCU_STRUCT_INIT(name);
+ struct srcu_struct name = __SRCU_STRUCT_INIT(name, name##_srcu_array);
#define DEFINE_STATIC_SRCU(name) \
static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
- static struct srcu_struct name = __SRCU_STRUCT_INIT(name);
+ static struct srcu_struct name = __SRCU_STRUCT_INIT(\
+ name, name##_srcu_array);
/**
* call_srcu() - Queue a callback for invocation after an SRCU grace period
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 14a8ff2..b15655f 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -25,6 +25,7 @@
#include <linux/rcupdate.h>
#include <linux/wait.h>
#include <linux/rbtree.h>
+#include <linux/atomic.h>
#include <uapi/linux/sysctl.h>
/* For the /proc/sys support */
diff --git a/include/linux/timer.h b/include/linux/timer.h
index 8c5a197..5fcd72c 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -241,7 +241,7 @@ extern void add_timer(struct timer_list *timer);
extern int try_to_del_timer_sync(struct timer_list *timer);
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
extern int del_timer_sync(struct timer_list *timer);
#else
# define del_timer_sync(t) del_timer(t)
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 5ca0951..44b3751 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -6,38 +6,37 @@
/*
* These routines enable/disable the pagefault handler in that
- * it will not take any locks and go straight to the fixup table.
- *
- * They have great resemblance to the preempt_disable/enable calls
- * and in fact they are identical; this is because currently there is
- * no other way to make the pagefault handlers do this. So we do
- * disable preemption but we don't necessarily care about that.
+ * it will not take any MM locks and go straight to the fixup table.
*/
-static inline void pagefault_disable(void)
+static inline void raw_pagefault_disable(void)
{
inc_preempt_count();
- /*
- * make sure to have issued the store before a pagefault
- * can hit.
- */
barrier();
}
-static inline void pagefault_enable(void)
+static inline void raw_pagefault_enable(void)
{
- /*
- * make sure to issue those last loads/stores before enabling
- * the pagefault handler again.
- */
barrier();
dec_preempt_count();
- /*
- * make sure we do..
- */
barrier();
preempt_check_resched();
}
+#ifndef CONFIG_PREEMPT_RT_FULL
+static inline void pagefault_disable(void)
+{
+ raw_pagefault_disable();
+}
+
+static inline void pagefault_enable(void)
+{
+ raw_pagefault_enable();
+}
+#else
+extern void pagefault_disable(void);
+extern void pagefault_enable(void);
+#endif
+
#ifndef ARCH_HAS_NOCACHE_UACCESS
static inline unsigned long __copy_from_user_inatomic_nocache(void *to,
@@ -77,9 +76,9 @@ static inline unsigned long __copy_from_user_nocache(void *to,
mm_segment_t old_fs = get_fs(); \
\
set_fs(KERNEL_DS); \
- pagefault_disable(); \
+ raw_pagefault_disable(); \
ret = __copy_from_user_inatomic(&(retval), (__force typeof(retval) __user *)(addr), sizeof(retval)); \
- pagefault_enable(); \
+ raw_pagefault_enable(); \
set_fs(old_fs); \
ret; \
})
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 06f28be..d115f62 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -26,6 +26,7 @@
#include <linux/errno.h>
#include <linux/rbtree.h>
+#include <linux/wait.h>
struct vm_area_struct;
struct mm_struct;
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index a67b384..1ea2fd5 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -29,7 +29,9 @@ DECLARE_PER_CPU(struct vm_event_state, vm_event_states);
static inline void __count_vm_event(enum vm_event_item item)
{
+ preempt_disable_rt();
__this_cpu_inc(vm_event_states.event[item]);
+ preempt_enable_rt();
}
static inline void count_vm_event(enum vm_event_item item)
@@ -39,7 +41,9 @@ static inline void count_vm_event(enum vm_event_item item)
static inline void __count_vm_events(enum vm_event_item item, long delta)
{
+ preempt_disable_rt();
__this_cpu_add(vm_event_states.event[item], delta);
+ preempt_enable_rt();
}
static inline void count_vm_events(enum vm_event_item item, long delta)
diff --git a/include/linux/wait-simple.h b/include/linux/wait-simple.h
new file mode 100644
index 0000000..f86bca2
--- /dev/null
+++ b/include/linux/wait-simple.h
@@ -0,0 +1,207 @@
+#ifndef _LINUX_WAIT_SIMPLE_H
+#define _LINUX_WAIT_SIMPLE_H
+
+#include <linux/spinlock.h>
+#include <linux/list.h>
+
+#include <asm/current.h>
+
+struct swaiter {
+ struct task_struct *task;
+ struct list_head node;
+};
+
+#define DEFINE_SWAITER(name) \
+ struct swaiter name = { \
+ .task = current, \
+ .node = LIST_HEAD_INIT((name).node), \
+ }
+
+struct swait_head {
+ raw_spinlock_t lock;
+ struct list_head list;
+};
+
+#define SWAIT_HEAD_INITIALIZER(name) { \
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \
+ .list = LIST_HEAD_INIT((name).list), \
+ }
+
+#define DEFINE_SWAIT_HEAD(name) \
+ struct swait_head name = SWAIT_HEAD_INITIALIZER(name)
+
+extern void __init_swait_head(struct swait_head *h, struct lock_class_key *key);
+
+#define init_swait_head(swh) \
+ do { \
+ static struct lock_class_key __key; \
+ \
+ __init_swait_head((swh), &__key); \
+ } while (0)
+
+/*
+ * Waiter functions
+ */
+extern void swait_prepare_locked(struct swait_head *head, struct swaiter *w);
+extern void swait_prepare(struct swait_head *head, struct swaiter *w, int state);
+extern void swait_finish_locked(struct swait_head *head, struct swaiter *w);
+extern void swait_finish(struct swait_head *head, struct swaiter *w);
+
+/* Check whether a head has waiters enqueued */
+static inline bool swaitqueue_active(struct swait_head *h)
+{
+ /* Make sure the condition is visible before checking list_empty() */
+ smp_mb();
+ return !list_empty(&h->list);
+}
+
+/*
+ * Wakeup functions
+ */
+extern unsigned int __swait_wake(struct swait_head *head, unsigned int state, unsigned int num);
+extern unsigned int __swait_wake_locked(struct swait_head *head, unsigned int state, unsigned int num);
+
+#define swait_wake(head) __swait_wake(head, TASK_NORMAL, 1)
+#define swait_wake_interruptible(head) __swait_wake(head, TASK_INTERRUPTIBLE, 1)
+#define swait_wake_all(head) __swait_wake(head, TASK_NORMAL, 0)
+#define swait_wake_all_interruptible(head) __swait_wake(head, TASK_INTERRUPTIBLE, 0)
+
+/*
+ * Event API
+ */
+#define __swait_event(wq, condition) \
+do { \
+ DEFINE_SWAITER(__wait); \
+ \
+ for (;;) { \
+ swait_prepare(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ schedule(); \
+ } \
+ swait_finish(&wq, &__wait); \
+} while (0)
+
+/**
+ * swait_event - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define swait_event(wq, condition) \
+do { \
+ if (condition) \
+ break; \
+ __swait_event(wq, condition); \
+} while (0)
+
+#define __swait_event_interruptible(wq, condition, ret) \
+do { \
+ DEFINE_SWAITER(__wait); \
+ \
+ for (;;) { \
+ swait_prepare(&wq, &__wait, TASK_INTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ if (signal_pending(current)) { \
+ ret = -ERESTARTSYS; \
+ break; \
+ } \
+ schedule(); \
+ } \
+ swait_finish(&wq, &__wait); \
+} while (0)
+
+#define __swait_event_interruptible_timeout(wq, condition, ret) \
+do { \
+ DEFINE_SWAITER(__wait); \
+ \
+ for (;;) { \
+ swait_prepare(&wq, &__wait, TASK_INTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ if (signal_pending(current)) { \
+ ret = -ERESTARTSYS; \
+ break; \
+ } \
+ ret = schedule_timeout(ret); \
+ if (!ret) \
+ break; \
+ } \
+ swait_finish(&wq, &__wait); \
+} while (0)
+
+/**
+ * swait_event_interruptible - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_INTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define swait_event_interruptible(wq, condition) \
+({ \
+ int __ret = 0; \
+ if (!(condition)) \
+ __swait_event_interruptible(wq, condition, __ret); \
+ __ret; \
+})
+
+#define swait_event_interruptible_timeout(wq, condition, timeout) \
+({ \
+ int __ret = timeout; \
+ if (!(condition)) \
+ __swait_event_interruptible_timeout(wq, condition, __ret); \
+ __ret; \
+})
+
+#define __swait_event_timeout(wq, condition, ret) \
+do { \
+ DEFINE_SWAITER(__wait); \
+ \
+ for (;;) { \
+ swait_prepare(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ ret = schedule_timeout(ret); \
+ if (!ret) \
+ break; \
+ } \
+ swait_finish(&wq, &__wait); \
+} while (0)
+
+/**
+ * swait_event_timeout - sleep until a condition gets true or a timeout elapses
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @timeout: timeout, in jiffies
+ *
+ * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ *
+ * The function returns 0 if the @timeout elapsed, and the remaining
+ * jiffies if the condition evaluated to true before the timeout elapsed.
+ */
+#define swait_event_timeout(wq, condition, timeout) \
+({ \
+ long __ret = timeout; \
+ if (!(condition)) \
+ __swait_event_timeout(wq, condition, __ret); \
+ __ret; \
+})
+
+#endif
diff --git a/include/linux/wait.h b/include/linux/wait.h
index a67fc16..68f7245 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -7,6 +7,7 @@
#include <linux/spinlock.h>
#include <asm/current.h>
#include <uapi/linux/wait.h>
+#include <linux/atomic.h>
typedef struct __wait_queue wait_queue_t;
typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
diff --git a/include/net/dst.h b/include/net/dst.h
index 3c4c944..a158a07 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -395,7 +395,7 @@ static inline void dst_confirm(struct dst_entry *dst)
static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n,
struct sk_buff *skb)
{
- const struct hh_cache *hh;
+ struct hh_cache *hh;
if (dst->pending_confirm) {
unsigned long now = jiffies;
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 536501a..a9d84bf 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -333,7 +333,7 @@ static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
}
#endif
-static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
+static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
{
unsigned int seq;
int hh_len;
@@ -388,7 +388,7 @@ struct neighbour_cb {
#define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
-static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
+static inline void neigh_ha_snapshot(char *dst, struct neighbour *n,
const struct net_device *dev)
{
unsigned int seq;
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index bf2ec22..5e9ce7f 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -57,6 +57,7 @@ struct netns_ipv4 {
int sysctl_icmp_echo_ignore_all;
int sysctl_icmp_echo_ignore_broadcasts;
+ int sysctl_icmp_echo_sysrq;
int sysctl_icmp_ignore_bogus_error_responses;
int sysctl_icmp_ratelimit;
int sysctl_icmp_ratemask;
diff --git a/include/trace/events/hist.h b/include/trace/events/hist.h
new file mode 100644
index 0000000..6122e42
--- /dev/null
+++ b/include/trace/events/hist.h
@@ -0,0 +1,72 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM hist
+
+#if !defined(_TRACE_HIST_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HIST_H
+
+#include "latency_hist.h"
+#include <linux/tracepoint.h>
+
+#if !defined(CONFIG_PREEMPT_OFF_HIST) && !defined(CONFIG_INTERRUPT_OFF_HIST)
+#define trace_preemptirqsoff_hist(a, b)
+#else
+TRACE_EVENT(preemptirqsoff_hist,
+
+ TP_PROTO(int reason, int starthist),
+
+ TP_ARGS(reason, starthist),
+
+ TP_STRUCT__entry(
+ __field(int, reason)
+ __field(int, starthist)
+ ),
+
+ TP_fast_assign(
+ __entry->reason = reason;
+ __entry->starthist = starthist;
+ ),
+
+ TP_printk("reason=%s starthist=%s", getaction(__entry->reason),
+ __entry->starthist ? "start" : "stop")
+);
+#endif
+
+#ifndef CONFIG_MISSED_TIMER_OFFSETS_HIST
+#define trace_hrtimer_interrupt(a, b, c, d)
+#else
+TRACE_EVENT(hrtimer_interrupt,
+
+ TP_PROTO(int cpu, long long offset, struct task_struct *curr,
+ struct task_struct *task),
+
+ TP_ARGS(cpu, offset, curr, task),
+
+ TP_STRUCT__entry(
+ __field(int, cpu)
+ __field(long long, offset)
+ __array(char, ccomm, TASK_COMM_LEN)
+ __field(int, cprio)
+ __array(char, tcomm, TASK_COMM_LEN)
+ __field(int, tprio)
+ ),
+
+ TP_fast_assign(
+ __entry->cpu = cpu;
+ __entry->offset = offset;
+ memcpy(__entry->ccomm, curr->comm, TASK_COMM_LEN);
+ __entry->cprio = curr->prio;
+ memcpy(__entry->tcomm, task != NULL ? task->comm : "<none>",
+ task != NULL ? TASK_COMM_LEN : 7);
+ __entry->tprio = task != NULL ? task->prio : -1;
+ ),
+
+ TP_printk("cpu=%d offset=%lld curr=%s[%d] thread=%s[%d]",
+ __entry->cpu, __entry->offset, __entry->ccomm,
+ __entry->cprio, __entry->tcomm, __entry->tprio)
+);
+#endif
+
+#endif /* _TRACE_HIST_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/include/trace/events/latency_hist.h b/include/trace/events/latency_hist.h
new file mode 100644
index 0000000..d3f2fbd
--- /dev/null
+++ b/include/trace/events/latency_hist.h
@@ -0,0 +1,29 @@
+#ifndef _LATENCY_HIST_H
+#define _LATENCY_HIST_H
+
+enum hist_action {
+ IRQS_ON,
+ PREEMPT_ON,
+ TRACE_STOP,
+ IRQS_OFF,
+ PREEMPT_OFF,
+ TRACE_START,
+};
+
+static char *actions[] = {
+ "IRQS_ON",
+ "PREEMPT_ON",
+ "TRACE_STOP",
+ "IRQS_OFF",
+ "PREEMPT_OFF",
+ "TRACE_START",
+};
+
+static inline char *getaction(int action)
+{
+ if (action >= 0 && action <= sizeof(actions)/sizeof(actions[0]))
+ return actions[action];
+ return "unknown";
+}
+
+#endif /* _LATENCY_HIST_H */
diff --git a/init/Kconfig b/init/Kconfig
index 3ecd8a1..f6aeea6 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -615,7 +615,7 @@ config RCU_FANOUT_EXACT
config RCU_FAST_NO_HZ
bool "Accelerate last non-dyntick-idle CPU's grace periods"
- depends on NO_HZ_COMMON && SMP
+ depends on NO_HZ_COMMON && SMP && !PREEMPT_RT_FULL
default n
help
This option permits CPUs to enter dynticks-idle state even if
@@ -642,7 +642,7 @@ config TREE_RCU_TRACE
config RCU_BOOST
bool "Enable RCU priority boosting"
depends on RT_MUTEXES && PREEMPT_RCU
- default n
+ default y if PREEMPT_RT_FULL
help
This option boosts the priority of preempted RCU readers that
block the current preemptible RCU grace period for too long.
@@ -1042,6 +1042,7 @@ config CFS_BANDWIDTH
config RT_GROUP_SCHED
bool "Group scheduling for SCHED_RR/FIFO"
depends on CGROUP_SCHED
+ depends on !PREEMPT_RT_FULL
default n
help
This feature lets you explicitly allocate real CPU bandwidth
@@ -1575,6 +1576,7 @@ choice
config SLAB
bool "SLAB"
+ depends on !PREEMPT_RT_FULL
help
The regular slab allocator that is established and known to work
well in all environments. It organizes cache hot objects in
@@ -1593,6 +1595,7 @@ config SLUB
config SLOB
depends on EXPERT
bool "SLOB (Simple Allocator)"
+ depends on !PREEMPT_RT_FULL
help
SLOB replaces the stock allocator with a drastically simpler
allocator. SLOB is generally more space efficient but
diff --git a/init/Makefile b/init/Makefile
index 7bc47ee..88cf473 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -33,4 +33,4 @@ silent_chk_compile.h = :
include/generated/compile.h: FORCE
@$($(quiet)chk_compile.h)
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@ \
- "$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CC) $(KBUILD_CFLAGS)"
+ "$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CONFIG_PREEMPT_RT_FULL)" "$(CC) $(KBUILD_CFLAGS)"
diff --git a/init/main.c b/init/main.c
index 63d3e8f..e8087f7 100644
--- a/init/main.c
+++ b/init/main.c
@@ -6,7 +6,7 @@
* GK 2/5/95 - Changed to support mounting root fs via NFS
* Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
* Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
- * Simplified starting of init: Michael A. Griffith <grif@acm.org>
+ * Simplified starting of init: Michael A. Griffith <grif@acm.org>
*/
#define DEBUG /* Enable initcall_debug */
@@ -74,6 +74,7 @@
#include <linux/ptrace.h>
#include <linux/blkdev.h>
#include <linux/elevator.h>
+#include <linux/posix-timers.h>
#include <linux/sched_clock.h>
#include <linux/context_tracking.h>
#include <linux/random.h>
@@ -507,6 +508,7 @@ asmlinkage void __init start_kernel(void)
setup_command_line(command_line);
setup_nr_cpu_ids();
setup_per_cpu_areas();
+ softirq_early_init();
smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
build_all_zonelists(NULL, NULL);
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index bb0248f..2276120 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -923,12 +923,17 @@ static inline void pipelined_send(struct mqueue_inode_info *info,
struct msg_msg *message,
struct ext_wait_queue *receiver)
{
+ /*
+ * Keep them in one critical section for PREEMPT_RT:
+ */
+ preempt_disable_rt();
receiver->msg = message;
list_del(&receiver->list);
receiver->state = STATE_PENDING;
wake_up_process(receiver->task);
smp_wmb();
receiver->state = STATE_READY;
+ preempt_enable_rt();
}
/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
@@ -942,13 +947,18 @@ static inline void pipelined_receive(struct mqueue_inode_info *info)
wake_up_interruptible(&info->wait_q);
return;
}
- if (msg_insert(sender->msg, info))
- return;
- list_del(&sender->list);
- sender->state = STATE_PENDING;
- wake_up_process(sender->task);
- smp_wmb();
- sender->state = STATE_READY;
+ /*
+ * Keep them in one critical section for PREEMPT_RT:
+ */
+ preempt_disable_rt();
+ if (!msg_insert(sender->msg, info)) {
+ list_del(&sender->list);
+ sender->state = STATE_PENDING;
+ wake_up_process(sender->task);
+ smp_wmb();
+ sender->state = STATE_READY;
+ }
+ preempt_enable_rt();
}
SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
diff --git a/ipc/msg.c b/ipc/msg.c
index 52770bf..1cf8b2c 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -253,10 +253,18 @@ static void expunge_all(struct msg_queue *msq, int res)
struct msg_receiver *msr, *t;
list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
+ /*
+ * Make sure that the wakeup doesnt preempt
+ * this CPU prematurely. (on PREEMPT_RT)
+ */
+ preempt_disable_rt();
+
msr->r_msg = NULL;
wake_up_process(msr->r_tsk);
smp_mb();
msr->r_msg = ERR_PTR(res);
+
+ preempt_enable_rt();
}
}
@@ -636,6 +644,12 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
!security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
msr->r_msgtype, msr->r_mode)) {
+ /*
+ * Make sure that the wakeup doesnt preempt
+ * this CPU prematurely. (on PREEMPT_RT)
+ */
+ preempt_disable_rt();
+
list_del(&msr->r_list);
if (msr->r_maxsize < msg->m_ts) {
msr->r_msg = NULL;
@@ -649,9 +663,11 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
wake_up_process(msr->r_tsk);
smp_mb();
msr->r_msg = msg;
+ preempt_enable_rt();
return 1;
}
+ preempt_enable_rt();
}
}
return 0;
diff --git a/ipc/sem.c b/ipc/sem.c
index db9d241..258b45e 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -666,6 +666,13 @@ undo:
static void wake_up_sem_queue_prepare(struct list_head *pt,
struct sem_queue *q, int error)
{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ struct task_struct *p = q->sleeper;
+ get_task_struct(p);
+ q->status = error;
+ wake_up_process(p);
+ put_task_struct(p);
+#else
if (list_empty(pt)) {
/*
* Hold preempt off so that we don't get preempted and have the
@@ -677,6 +684,7 @@ static void wake_up_sem_queue_prepare(struct list_head *pt,
q->pid = error;
list_add_tail(&q->list, pt);
+#endif
}
/**
@@ -690,6 +698,7 @@ static void wake_up_sem_queue_prepare(struct list_head *pt,
*/
static void wake_up_sem_queue_do(struct list_head *pt)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
struct sem_queue *q, *t;
int did_something;
@@ -702,6 +711,7 @@ static void wake_up_sem_queue_do(struct list_head *pt)
}
if (did_something)
preempt_enable();
+#endif
}
static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index d2b32ac..8bb92eb 100644
--- a/kernel/Kconfig.locks
+++ b/kernel/Kconfig.locks
@@ -222,4 +222,4 @@ endif
config MUTEX_SPIN_ON_OWNER
def_bool y
- depends on SMP && !DEBUG_MUTEXES
+ depends on SMP && !DEBUG_MUTEXES && !PREEMPT_RT_FULL
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 3f9c974..11dbe26 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -1,3 +1,16 @@
+config PREEMPT
+ bool
+ select PREEMPT_COUNT
+
+config PREEMPT_RT_BASE
+ bool
+ select PREEMPT
+
+config HAVE_PREEMPT_LAZY
+ bool
+
+config PREEMPT_LAZY
+ def_bool y if HAVE_PREEMPT_LAZY && PREEMPT_RT_FULL
choice
prompt "Preemption Model"
@@ -33,9 +46,9 @@ config PREEMPT_VOLUNTARY
Select this if you are building a kernel for a desktop system.
-config PREEMPT
+config PREEMPT__LL
bool "Preemptible Kernel (Low-Latency Desktop)"
- select PREEMPT_COUNT
+ select PREEMPT
select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK
help
This option reduces the latency of the kernel by making
@@ -52,6 +65,22 @@ config PREEMPT
embedded system with latency requirements in the milliseconds
range.
+config PREEMPT_RTB
+ bool "Preemptible Kernel (Basic RT)"
+ select PREEMPT_RT_BASE
+ help
+ This option is basically the same as (Low-Latency Desktop) but
+ enables changes which are preliminary for the full preemptible
+ RT kernel.
+
+config PREEMPT_RT_FULL
+ bool "Fully Preemptible Kernel (RT)"
+ depends on IRQ_FORCED_THREADING
+ select PREEMPT_RT_BASE
+ select PREEMPT_RCU
+ help
+ All and everything
+
endchoice
config PREEMPT_COUNT
diff --git a/kernel/Makefile b/kernel/Makefile
index 1ce4755..b3ff0a8 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -7,10 +7,10 @@ obj-y = fork.o exec_domain.o panic.o \
sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o task_work.o \
rcupdate.o extable.o params.o posix-timers.o \
- kthread.o wait.o sys_ni.o posix-cpu-timers.o mutex.o \
- hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
+ kthread.o wait.o sys_ni.o posix-cpu-timers.o \
+ hrtimer.o nsproxy.o srcu.o semaphore.o \
notifier.o ksysfs.o cred.o reboot.o \
- async.o range.o groups.o lglock.o smpboot.o
+ async.o range.o groups.o lglock.o smpboot.o wait-simple.o
ifdef CONFIG_FUNCTION_TRACER
# Do not trace debug files and internal ftrace files
@@ -33,7 +33,11 @@ obj-$(CONFIG_FREEZER) += freezer.o
obj-$(CONFIG_PROFILING) += profile.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-y += time/
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
+obj-y += mutex.o
obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
+obj-y += rwsem.o
+endif
obj-$(CONFIG_LOCKDEP) += lockdep.o
ifeq ($(CONFIG_PROC_FS),y)
obj-$(CONFIG_LOCKDEP) += lockdep_proc.o
@@ -45,6 +49,7 @@ endif
obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
+obj-$(CONFIG_PREEMPT_RT_FULL) += rt.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += smp.o
ifneq ($(CONFIG_SMP),y)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index d7f07a2..ba7416b 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -63,6 +63,290 @@ static struct {
.refcount = 0,
};
+/**
+ * hotplug_pcp - per cpu hotplug descriptor
+ * @unplug: set when pin_current_cpu() needs to sync tasks
+ * @sync_tsk: the task that waits for tasks to finish pinned sections
+ * @refcount: counter of tasks in pinned sections
+ * @grab_lock: set when the tasks entering pinned sections should wait
+ * @synced: notifier for @sync_tsk to tell cpu_down it's finished
+ * @mutex: the mutex to make tasks wait (used when @grab_lock is true)
+ * @mutex_init: zero if the mutex hasn't been initialized yet.
+ *
+ * Although @unplug and @sync_tsk may point to the same task, the @unplug
+ * is used as a flag and still exists after @sync_tsk has exited and
+ * @sync_tsk set to NULL.
+ */
+struct hotplug_pcp {
+ struct task_struct *unplug;
+ struct task_struct *sync_tsk;
+ int refcount;
+ int grab_lock;
+ struct completion synced;
+ struct completion unplug_wait;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /*
+ * Note, on PREEMPT_RT, the hotplug lock must save the state of
+ * the task, otherwise the mutex will cause the task to fail
+ * to sleep when required. (Because it's called from migrate_disable())
+ *
+ * The spinlock_t on PREEMPT_RT is a mutex that saves the task's
+ * state.
+ */
+ spinlock_t lock;
+#else
+ struct mutex mutex;
+#endif
+ int mutex_init;
+};
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define hotplug_lock(hp) rt_spin_lock(&(hp)->lock)
+# define hotplug_unlock(hp) rt_spin_unlock(&(hp)->lock)
+#else
+# define hotplug_lock(hp) mutex_lock(&(hp)->mutex)
+# define hotplug_unlock(hp) mutex_unlock(&(hp)->mutex)
+#endif
+
+static DEFINE_PER_CPU(struct hotplug_pcp, hotplug_pcp);
+
+/**
+ * pin_current_cpu - Prevent the current cpu from being unplugged
+ *
+ * Lightweight version of get_online_cpus() to prevent cpu from being
+ * unplugged when code runs in a migration disabled region.
+ *
+ * Must be called with preemption disabled (preempt_count = 1)!
+ */
+void pin_current_cpu(void)
+{
+ struct hotplug_pcp *hp;
+ int force = 0;
+
+retry:
+ hp = &__get_cpu_var(hotplug_pcp);
+
+ if (!hp->unplug || hp->refcount || force || preempt_count() > 1 ||
+ hp->unplug == current) {
+ hp->refcount++;
+ return;
+ }
+ if (hp->grab_lock) {
+ preempt_enable();
+ hotplug_lock(hp);
+ hotplug_unlock(hp);
+ } else {
+ preempt_enable();
+ /*
+ * Try to push this task off of this CPU.
+ */
+ if (!migrate_me()) {
+ preempt_disable();
+ hp = &__get_cpu_var(hotplug_pcp);
+ if (!hp->grab_lock) {
+ /*
+ * Just let it continue it's already pinned
+ * or about to sleep.
+ */
+ force = 1;
+ goto retry;
+ }
+ preempt_enable();
+ }
+ }
+ preempt_disable();
+ goto retry;
+}
+
+/**
+ * unpin_current_cpu - Allow unplug of current cpu
+ *
+ * Must be called with preemption or interrupts disabled!
+ */
+void unpin_current_cpu(void)
+{
+ struct hotplug_pcp *hp = &__get_cpu_var(hotplug_pcp);
+
+ WARN_ON(hp->refcount <= 0);
+
+ /* This is safe. sync_unplug_thread is pinned to this cpu */
+ if (!--hp->refcount && hp->unplug && hp->unplug != current)
+ wake_up_process(hp->unplug);
+}
+
+static void wait_for_pinned_cpus(struct hotplug_pcp *hp)
+{
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ while (hp->refcount) {
+ schedule_preempt_disabled();
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ }
+}
+
+static int sync_unplug_thread(void *data)
+{
+ struct hotplug_pcp *hp = data;
+
+ wait_for_completion(&hp->unplug_wait);
+ preempt_disable();
+ hp->unplug = current;
+ wait_for_pinned_cpus(hp);
+
+ /*
+ * This thread will synchronize the cpu_down() with threads
+ * that have pinned the CPU. When the pinned CPU count reaches
+ * zero, we inform the cpu_down code to continue to the next step.
+ */
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ preempt_enable();
+ complete(&hp->synced);
+
+ /*
+ * If all succeeds, the next step will need tasks to wait till
+ * the CPU is offline before continuing. To do this, the grab_lock
+ * is set and tasks going into pin_current_cpu() will block on the
+ * mutex. But we still need to wait for those that are already in
+ * pinned CPU sections. If the cpu_down() failed, the kthread_should_stop()
+ * will kick this thread out.
+ */
+ while (!hp->grab_lock && !kthread_should_stop()) {
+ schedule();
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ }
+
+ /* Make sure grab_lock is seen before we see a stale completion */
+ smp_mb();
+
+ /*
+ * Now just before cpu_down() enters stop machine, we need to make
+ * sure all tasks that are in pinned CPU sections are out, and new
+ * tasks will now grab the lock, keeping them from entering pinned
+ * CPU sections.
+ */
+ if (!kthread_should_stop()) {
+ preempt_disable();
+ wait_for_pinned_cpus(hp);
+ preempt_enable();
+ complete(&hp->synced);
+ }
+
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ while (!kthread_should_stop()) {
+ schedule();
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ }
+ set_current_state(TASK_RUNNING);
+
+ /*
+ * Force this thread off this CPU as it's going down and
+ * we don't want any more work on this CPU.
+ */
+ current->flags &= ~PF_NO_SETAFFINITY;
+ do_set_cpus_allowed(current, cpu_present_mask);
+ migrate_me();
+ return 0;
+}
+
+static void __cpu_unplug_sync(struct hotplug_pcp *hp)
+{
+ wake_up_process(hp->sync_tsk);
+ wait_for_completion(&hp->synced);
+}
+
+static void __cpu_unplug_wait(unsigned int cpu)
+{
+ struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+
+ complete(&hp->unplug_wait);
+ wait_for_completion(&hp->synced);
+}
+
+/*
+ * Start the sync_unplug_thread on the target cpu and wait for it to
+ * complete.
+ */
+static int cpu_unplug_begin(unsigned int cpu)
+{
+ struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+ int err;
+
+ /* Protected by cpu_hotplug.lock */
+ if (!hp->mutex_init) {
+#ifdef CONFIG_PREEMPT_RT_FULL
+ spin_lock_init(&hp->lock);
+#else
+ mutex_init(&hp->mutex);
+#endif
+ hp->mutex_init = 1;
+ }
+
+ /* Inform the scheduler to migrate tasks off this CPU */
+ tell_sched_cpu_down_begin(cpu);
+
+ init_completion(&hp->synced);
+ init_completion(&hp->unplug_wait);
+
+ hp->sync_tsk = kthread_create(sync_unplug_thread, hp, "sync_unplug/%d", cpu);
+ if (IS_ERR(hp->sync_tsk)) {
+ err = PTR_ERR(hp->sync_tsk);
+ hp->sync_tsk = NULL;
+ return err;
+ }
+ kthread_bind(hp->sync_tsk, cpu);
+
+ /*
+ * Wait for tasks to get out of the pinned sections,
+ * it's still OK if new tasks enter. Some CPU notifiers will
+ * wait for tasks that are going to enter these sections and
+ * we must not have them block.
+ */
+ wake_up_process(hp->sync_tsk);
+ return 0;
+}
+
+static void cpu_unplug_sync(unsigned int cpu)
+{
+ struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+
+ init_completion(&hp->synced);
+ /* The completion needs to be initialzied before setting grab_lock */
+ smp_wmb();
+
+ /* Grab the mutex before setting grab_lock */
+ hotplug_lock(hp);
+ hp->grab_lock = 1;
+
+ /*
+ * The CPU notifiers have been completed.
+ * Wait for tasks to get out of pinned CPU sections and have new
+ * tasks block until the CPU is completely down.
+ */
+ __cpu_unplug_sync(hp);
+
+ /* All done with the sync thread */
+ kthread_stop(hp->sync_tsk);
+ hp->sync_tsk = NULL;
+}
+
+static void cpu_unplug_done(unsigned int cpu)
+{
+ struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+
+ hp->unplug = NULL;
+ /* Let all tasks know cpu unplug is finished before cleaning up */
+ smp_wmb();
+
+ if (hp->sync_tsk)
+ kthread_stop(hp->sync_tsk);
+
+ if (hp->grab_lock) {
+ hotplug_unlock(hp);
+ /* protected by cpu_hotplug.lock */
+ hp->grab_lock = 0;
+ }
+ tell_sched_cpu_down_done(cpu);
+}
+
void get_online_cpus(void)
{
might_sleep();
@@ -79,15 +363,14 @@ void put_online_cpus(void)
{
if (cpu_hotplug.active_writer == current)
return;
- mutex_lock(&cpu_hotplug.lock);
+ mutex_lock(&cpu_hotplug.lock);
if (WARN_ON(!cpu_hotplug.refcount))
cpu_hotplug.refcount++; /* try to fix things up */
if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer))
wake_up_process(cpu_hotplug.active_writer);
mutex_unlock(&cpu_hotplug.lock);
-
}
EXPORT_SYMBOL_GPL(put_online_cpus);
@@ -282,13 +565,15 @@ static int __ref take_cpu_down(void *_param)
/* Requires cpu_add_remove_lock to be held */
static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
{
- int err, nr_calls = 0;
+ int mycpu, err, nr_calls = 0;
void *hcpu = (void *)(long)cpu;
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct take_cpu_down_param tcd_param = {
.mod = mod,
.hcpu = hcpu,
};
+ cpumask_var_t cpumask;
+ cpumask_var_t cpumask_org;
if (num_online_cpus() == 1)
return -EBUSY;
@@ -296,7 +581,34 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
if (!cpu_online(cpu))
return -EINVAL;
+ /* Move the downtaker off the unplug cpu */
+ if (!alloc_cpumask_var(&cpumask, GFP_KERNEL))
+ return -ENOMEM;
+ if (!alloc_cpumask_var(&cpumask_org, GFP_KERNEL)) {
+ free_cpumask_var(cpumask);
+ return -ENOMEM;
+ }
+
+ cpumask_copy(cpumask_org, tsk_cpus_allowed(current));
+ cpumask_andnot(cpumask, cpu_online_mask, cpumask_of(cpu));
+ set_cpus_allowed_ptr(current, cpumask);
+ free_cpumask_var(cpumask);
+ migrate_disable();
+ mycpu = smp_processor_id();
+ if (mycpu == cpu) {
+ printk(KERN_ERR "Yuck! Still on unplug CPU\n!");
+ migrate_enable();
+ err = -EBUSY;
+ goto restore_cpus;
+ }
+ migrate_enable();
+
cpu_hotplug_begin();
+ err = cpu_unplug_begin(cpu);
+ if (err) {
+ printk("cpu_unplug_begin(%d) failed\n", cpu);
+ goto out_cancel;
+ }
err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
if (err) {
@@ -306,8 +618,13 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
__func__, cpu);
goto out_release;
}
+
+ __cpu_unplug_wait(cpu);
smpboot_park_threads(cpu);
+ /* Notifiers are done. Don't let any more tasks pin this CPU. */
+ cpu_unplug_sync(cpu);
+
err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) {
/* CPU didn't die: tell everyone. Can't complain. */
@@ -336,9 +653,14 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
check_for_tasks(cpu);
out_release:
+ cpu_unplug_done(cpu);
+out_cancel:
cpu_hotplug_done();
if (!err)
cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
+restore_cpus:
+ set_cpus_allowed_ptr(current, cpumask_org);
+ free_cpumask_var(cpumask_org);
return err;
}
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 14ff484..399dba6 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -554,7 +554,6 @@ int vkdb_printf(const char *fmt, va_list ap)
int linecount;
int colcount;
int logging, saved_loglevel = 0;
- int saved_trap_printk;
int got_printf_lock = 0;
int retlen = 0;
int fnd, len;
@@ -565,8 +564,6 @@ int vkdb_printf(const char *fmt, va_list ap)
unsigned long uninitialized_var(flags);
preempt_disable();
- saved_trap_printk = kdb_trap_printk;
- kdb_trap_printk = 0;
/* Serialize kdb_printf if multiple cpus try to write at once.
* But if any cpu goes recursive in kdb, just print the output,
@@ -833,7 +830,6 @@ kdb_print_out:
} else {
__release(kdb_printf_lock);
}
- kdb_trap_printk = saved_trap_printk;
preempt_enable();
return retlen;
}
@@ -843,9 +839,11 @@ int kdb_printf(const char *fmt, ...)
va_list ap;
int r;
+ kdb_trap_printk++;
va_start(ap, fmt);
r = vkdb_printf(fmt, ap);
va_end(ap);
+ kdb_trap_printk--;
return r;
}
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6dde811..40c3397 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6033,6 +6033,7 @@ static void perf_swevent_init_hrtimer(struct perf_event *event)
hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hwc->hrtimer.function = perf_swevent_hrtimer;
+ hwc->hrtimer.irqsafe = 1;
/*
* Since hrtimers have a fixed rate, we can do a static freq->period
diff --git a/kernel/exit.c b/kernel/exit.c
index a949819..7493b32 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -145,7 +145,7 @@ static void __exit_signal(struct task_struct *tsk)
* Do this under ->siglock, we can race with another thread
* doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
*/
- flush_sigqueue(&tsk->pending);
+ flush_task_sigqueue(tsk);
tsk->sighand = NULL;
spin_unlock(&sighand->siglock);
diff --git a/kernel/fork.c b/kernel/fork.c
index 458953c..ae9a1a4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -94,7 +94,7 @@ int max_threads; /* tunable limit on nr_threads */
DEFINE_PER_CPU(unsigned long, process_counts) = 0;
-__cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
+DEFINE_RWLOCK(tasklist_lock); /* outer */
#ifdef CONFIG_PROVE_RCU
int lockdep_tasklist_lock_is_held(void)
@@ -230,7 +230,9 @@ static inline void put_signal_struct(struct signal_struct *sig)
if (atomic_dec_and_test(&sig->sigcnt))
free_signal_struct(sig);
}
-
+#ifdef CONFIG_PREEMPT_RT_BASE
+static
+#endif
void __put_task_struct(struct task_struct *tsk)
{
WARN_ON(!tsk->exit_state);
@@ -245,7 +247,18 @@ void __put_task_struct(struct task_struct *tsk)
if (!profile_handoff_task(tsk))
free_task(tsk);
}
+#ifndef CONFIG_PREEMPT_RT_BASE
EXPORT_SYMBOL_GPL(__put_task_struct);
+#else
+void __put_task_struct_cb(struct rcu_head *rhp)
+{
+ struct task_struct *tsk = container_of(rhp, struct task_struct, put_rcu);
+
+ __put_task_struct(tsk);
+
+}
+EXPORT_SYMBOL_GPL(__put_task_struct_cb);
+#endif
void __init __weak arch_task_cache_init(void) { }
@@ -598,6 +611,19 @@ void __mmdrop(struct mm_struct *mm)
}
EXPORT_SYMBOL_GPL(__mmdrop);
+#ifdef CONFIG_PREEMPT_RT_BASE
+/*
+ * RCU callback for delayed mm drop. Not strictly rcu, but we don't
+ * want another facility to make this work.
+ */
+void __mmdrop_delayed(struct rcu_head *rhp)
+{
+ struct mm_struct *mm = container_of(rhp, struct mm_struct, delayed_drop);
+
+ __mmdrop(mm);
+}
+#endif
+
/*
* Decrement the use count and release all resources for an mm.
*/
@@ -1107,6 +1133,9 @@ void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
*/
static void posix_cpu_timers_init(struct task_struct *tsk)
{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ tsk->posix_timer_list = NULL;
+#endif
tsk->cputime_expires.prof_exp = 0;
tsk->cputime_expires.virt_exp = 0;
tsk->cputime_expires.sched_exp = 0;
@@ -1235,6 +1264,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
spin_lock_init(&p->alloc_lock);
init_sigpending(&p->pending);
+ p->sigqueue_cache = NULL;
p->utime = p->stime = p->gtime = 0;
p->utimescaled = p->stimescaled = 0;
@@ -1242,7 +1272,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->prev_cputime.utime = p->prev_cputime.stime = 0;
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
- seqlock_init(&p->vtime_seqlock);
+ raw_spin_lock_init(&p->vtime_lock);
+ seqcount_init(&p->vtime_seq);
p->vtime_snap = 0;
p->vtime_snap_whence = VTIME_SLEEPING;
#endif
@@ -1295,6 +1326,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->hardirq_context = 0;
p->softirq_context = 0;
#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+ p->pagefault_disabled = 0;
+#endif
#ifdef CONFIG_LOCKDEP
p->lockdep_depth = 0; /* no locks held yet */
p->curr_chain_key = 0;
@@ -1656,7 +1690,7 @@ SYSCALL_DEFINE0(fork)
#ifdef __ARCH_WANT_SYS_VFORK
SYSCALL_DEFINE0(vfork)
{
- return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
0, NULL, NULL);
}
#endif
diff --git a/kernel/futex.c b/kernel/futex.c
index 2317548..3b85a95 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -573,7 +573,9 @@ void exit_pi_state_list(struct task_struct *curr)
* task still owns the PI-state:
*/
if (head->next != next) {
+ raw_spin_unlock_irq(&curr->pi_lock);
spin_unlock(&hb->lock);
+ raw_spin_lock_irq(&curr->pi_lock);
continue;
}
@@ -1447,6 +1449,16 @@ retry_private:
requeue_pi_wake_futex(this, &key2, hb2);
drop_count++;
continue;
+ } else if (ret == -EAGAIN) {
+ /*
+ * Waiter was woken by timeout or
+ * signal and has set pi_blocked_on to
+ * PI_WAKEUP_INPROGRESS before we
+ * tried to enqueue it on the rtmutex.
+ */
+ this->pi_state = NULL;
+ free_pi_state(pi_state);
+ continue;
} else if (ret) {
/* -EDEADLK */
this->pi_state = NULL;
@@ -2290,7 +2302,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
struct hrtimer_sleeper timeout, *to = NULL;
struct rt_mutex_waiter rt_waiter;
struct rt_mutex *pi_mutex = NULL;
- struct futex_hash_bucket *hb;
+ struct futex_hash_bucket *hb, *hb2;
union futex_key key2 = FUTEX_KEY_INIT;
struct futex_q q = futex_q_init;
int res, ret;
@@ -2315,8 +2327,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
* The waiter is allocated on our stack, manipulated by the requeue
* code while we sleep on uaddr.
*/
- debug_rt_mutex_init_waiter(&rt_waiter);
- rt_waiter.task = NULL;
+ rt_mutex_init_waiter(&rt_waiter, false);
ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, VERIFY_WRITE);
if (unlikely(ret != 0))
@@ -2337,20 +2348,55 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
/* Queue the futex_q, drop the hb lock, wait for wakeup. */
futex_wait_queue_me(hb, &q, to);
- spin_lock(&hb->lock);
- ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
- spin_unlock(&hb->lock);
- if (ret)
- goto out_put_keys;
+ /*
+ * On RT we must avoid races with requeue and trying to block
+ * on two mutexes (hb->lock and uaddr2's rtmutex) by
+ * serializing access to pi_blocked_on with pi_lock.
+ */
+ raw_spin_lock_irq(&current->pi_lock);
+ if (current->pi_blocked_on) {
+ /*
+ * We have been requeued or are in the process of
+ * being requeued.
+ */
+ raw_spin_unlock_irq(&current->pi_lock);
+ } else {
+ /*
+ * Setting pi_blocked_on to PI_WAKEUP_INPROGRESS
+ * prevents a concurrent requeue from moving us to the
+ * uaddr2 rtmutex. After that we can safely acquire
+ * (and possibly block on) hb->lock.
+ */
+ current->pi_blocked_on = PI_WAKEUP_INPROGRESS;
+ raw_spin_unlock_irq(&current->pi_lock);
+
+ spin_lock(&hb->lock);
+
+ /*
+ * Clean up pi_blocked_on. We might leak it otherwise
+ * when we succeeded with the hb->lock in the fast
+ * path.
+ */
+ raw_spin_lock_irq(&current->pi_lock);
+ current->pi_blocked_on = NULL;
+ raw_spin_unlock_irq(&current->pi_lock);
+
+ ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
+ spin_unlock(&hb->lock);
+ if (ret)
+ goto out_put_keys;
+ }
/*
- * In order for us to be here, we know our q.key == key2, and since
- * we took the hb->lock above, we also know that futex_requeue() has
- * completed and we no longer have to concern ourselves with a wakeup
- * race with the atomic proxy lock acquisition by the requeue code. The
- * futex_requeue dropped our key1 reference and incremented our key2
- * reference count.
+ * In order to be here, we have either been requeued, are in
+ * the process of being requeued, or requeue successfully
+ * acquired uaddr2 on our behalf. If pi_blocked_on was
+ * non-null above, we may be racing with a requeue. Do not
+ * rely on q->lock_ptr to be hb2->lock until after blocking on
+ * hb->lock or hb2->lock. The futex_requeue dropped our key1
+ * reference and incremented our key2 reference count.
*/
+ hb2 = hash_futex(&key2);
/* Check if the requeue code acquired the second futex for us. */
if (!q.rt_waiter) {
@@ -2359,9 +2405,10 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
* did a lock-steal - fix up the PI-state in that case.
*/
if (q.pi_state && (q.pi_state->owner != current)) {
- spin_lock(q.lock_ptr);
+ spin_lock(&hb2->lock);
+ BUG_ON(&hb2->lock != q.lock_ptr);
ret = fixup_pi_state_owner(uaddr2, &q, current);
- spin_unlock(q.lock_ptr);
+ spin_unlock(&hb2->lock);
}
} else {
/*
@@ -2374,7 +2421,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
ret = rt_mutex_finish_proxy_lock(pi_mutex, to, &rt_waiter, 1);
debug_rt_mutex_free_waiter(&rt_waiter);
- spin_lock(q.lock_ptr);
+ spin_lock(&hb2->lock);
+ BUG_ON(&hb2->lock != q.lock_ptr);
/*
* Fixup the pi_state owner and possibly acquire the lock if we
* haven't already.
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 383319b..c19183d 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -47,11 +47,13 @@
#include <linux/sched/sysctl.h>
#include <linux/sched/rt.h>
#include <linux/timer.h>
+#include <linux/kthread.h>
#include <linux/freezer.h>
#include <asm/uaccess.h>
#include <trace/events/timer.h>
+#include <trace/events/hist.h>
/*
* The timer bases:
@@ -607,8 +609,7 @@ static int hrtimer_reprogram(struct hrtimer *timer,
* When the callback is running, we do not reprogram the clock event
* device. The timer callback is either running on a different CPU or
* the callback is executed in the hrtimer_interrupt context. The
- * reprogramming is handled either by the softirq, which called the
- * callback or at the end of the hrtimer_interrupt.
+ * reprogramming is handled at the end of the hrtimer_interrupt.
*/
if (hrtimer_callback_running(timer))
return 0;
@@ -643,6 +644,9 @@ static int hrtimer_reprogram(struct hrtimer *timer,
return res;
}
+static void __run_hrtimer(struct hrtimer *timer, ktime_t *now);
+static int hrtimer_rt_defer(struct hrtimer *timer);
+
/*
* Initialize the high resolution related parts of cpu_base
*/
@@ -659,9 +663,18 @@ static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
* and expiry check is done in the hrtimer_interrupt or in the softirq.
*/
static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
- struct hrtimer_clock_base *base)
+ struct hrtimer_clock_base *base,
+ int wakeup)
{
- return base->cpu_base->hres_active && hrtimer_reprogram(timer, base);
+ if (!(base->cpu_base->hres_active && hrtimer_reprogram(timer, base)))
+ return 0;
+ if (!wakeup)
+ return -ETIME;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ if (!hrtimer_rt_defer(timer))
+ return -ETIME;
+#endif
+ return 1;
}
static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
@@ -729,6 +742,44 @@ static void clock_was_set_work(struct work_struct *work)
static DECLARE_WORK(hrtimer_work, clock_was_set_work);
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * RT can not call schedule_work from real interrupt context.
+ * Need to make a thread to do the real work.
+ */
+static struct task_struct *clock_set_delay_thread;
+static bool do_clock_set_delay;
+
+static int run_clock_set_delay(void *ignore)
+{
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (do_clock_set_delay) {
+ do_clock_set_delay = false;
+ schedule_work(&hrtimer_work);
+ }
+ schedule();
+ }
+ __set_current_state(TASK_RUNNING);
+ return 0;
+}
+
+void clock_was_set_delayed(void)
+{
+ do_clock_set_delay = true;
+ /* Make visible before waking up process */
+ smp_wmb();
+ wake_up_process(clock_set_delay_thread);
+}
+
+static __init int create_clock_set_delay_thread(void)
+{
+ clock_set_delay_thread = kthread_run(run_clock_set_delay, NULL, "kclksetdelayd");
+ BUG_ON(!clock_set_delay_thread);
+ return 0;
+}
+early_initcall(create_clock_set_delay_thread);
+#else /* PREEMPT_RT_FULL */
/*
* Called from timekeeping and resume code to reprogramm the hrtimer
* interrupt device on all cpus.
@@ -737,6 +788,7 @@ void clock_was_set_delayed(void)
{
schedule_work(&hrtimer_work);
}
+#endif
#else
@@ -746,12 +798,18 @@ static inline int hrtimer_switch_to_hres(void) { return 0; }
static inline void
hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
- struct hrtimer_clock_base *base)
+ struct hrtimer_clock_base *base,
+ int wakeup)
{
return 0;
}
static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
static inline void retrigger_next_event(void *arg) { }
+static inline int hrtimer_reprogram(struct hrtimer *timer,
+ struct hrtimer_clock_base *base)
+{
+ return 0;
+}
#endif /* CONFIG_HIGH_RES_TIMERS */
@@ -870,6 +928,32 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
}
EXPORT_SYMBOL_GPL(hrtimer_forward);
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define wake_up_timer_waiters(b) wake_up(&(b)->wait)
+
+/**
+ * hrtimer_wait_for_timer - Wait for a running timer
+ *
+ * @timer: timer to wait for
+ *
+ * The function waits in case the timers callback function is
+ * currently executed on the waitqueue of the timer base. The
+ * waitqueue is woken up after the timer callback function has
+ * finished execution.
+ */
+void hrtimer_wait_for_timer(const struct hrtimer *timer)
+{
+ struct hrtimer_clock_base *base = timer->base;
+
+ if (base && base->cpu_base && !timer->irqsafe)
+ wait_event(base->cpu_base->wait,
+ !(timer->state & HRTIMER_STATE_CALLBACK));
+}
+
+#else
+# define wake_up_timer_waiters(b) do { } while (0)
+#endif
+
/*
* enqueue_hrtimer - internal function to (re)start a timer
*
@@ -913,6 +997,11 @@ static void __remove_hrtimer(struct hrtimer *timer,
if (!(timer->state & HRTIMER_STATE_ENQUEUED))
goto out;
+ if (unlikely(!list_empty(&timer->cb_entry))) {
+ list_del_init(&timer->cb_entry);
+ goto out;
+ }
+
next_timer = timerqueue_getnext(&base->active);
timerqueue_del(&base->active, &timer->node);
if (&timer->node == next_timer) {
@@ -997,6 +1086,17 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
#endif
}
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ {
+ ktime_t now = new_base->get_time();
+
+ if (ktime_to_ns(tim) < ktime_to_ns(now))
+ timer->praecox = now;
+ else
+ timer->praecox = ktime_set(0, 0);
+ }
+#endif
+
hrtimer_set_expires_range_ns(timer, tim, delta_ns);
timer_stats_hrtimer_set_start_info(timer);
@@ -1009,9 +1109,19 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
*
* XXX send_remote_softirq() ?
*/
- if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)
- && hrtimer_enqueue_reprogram(timer, new_base)) {
- if (wakeup) {
+ if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)) {
+ ret = hrtimer_enqueue_reprogram(timer, new_base, wakeup);
+ if (ret < 0) {
+ /*
+ * In case we failed to reprogram the timer (mostly
+ * because out current timer is already elapsed),
+ * remove it again and report a failure. This avoids
+ * stale base->first entries.
+ */
+ debug_deactivate(timer);
+ __remove_hrtimer(timer, new_base,
+ timer->state & HRTIMER_STATE_CALLBACK, 0);
+ } else if (ret > 0) {
/*
* We need to drop cpu_base->lock to avoid a
* lock ordering issue vs. rq->lock.
@@ -1019,9 +1129,7 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
raw_spin_unlock(&new_base->cpu_base->lock);
raise_softirq_irqoff(HRTIMER_SOFTIRQ);
local_irq_restore(flags);
- return ret;
- } else {
- __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+ return 0;
}
}
@@ -1111,7 +1219,7 @@ int hrtimer_cancel(struct hrtimer *timer)
if (ret >= 0)
return ret;
- cpu_relax();
+ hrtimer_wait_for_timer(timer);
}
}
EXPORT_SYMBOL_GPL(hrtimer_cancel);
@@ -1190,6 +1298,7 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
base = hrtimer_clockid_to_base(clock_id);
timer->base = &cpu_base->clock_base[base];
+ INIT_LIST_HEAD(&timer->cb_entry);
timerqueue_init(&timer->node);
#ifdef CONFIG_TIMER_STATS
@@ -1273,6 +1382,126 @@ static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
timer->state &= ~HRTIMER_STATE_CALLBACK;
}
+static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+static void hrtimer_rt_reprogram(int restart, struct hrtimer *timer,
+ struct hrtimer_clock_base *base)
+{
+ /*
+ * Note, we clear the callback flag before we requeue the
+ * timer otherwise we trigger the callback_running() check
+ * in hrtimer_reprogram().
+ */
+ timer->state &= ~HRTIMER_STATE_CALLBACK;
+
+ if (restart != HRTIMER_NORESTART) {
+ BUG_ON(hrtimer_active(timer));
+ /*
+ * Enqueue the timer, if it's the leftmost timer then
+ * we need to reprogram it.
+ */
+ if (!enqueue_hrtimer(timer, base))
+ return;
+
+#ifndef CONFIG_HIGH_RES_TIMERS
+ }
+#else
+ if (base->cpu_base->hres_active &&
+ hrtimer_reprogram(timer, base))
+ goto requeue;
+
+ } else if (hrtimer_active(timer)) {
+ /*
+ * If the timer was rearmed on another CPU, reprogram
+ * the event device.
+ */
+ if (&timer->node == base->active.next &&
+ base->cpu_base->hres_active &&
+ hrtimer_reprogram(timer, base))
+ goto requeue;
+ }
+ return;
+
+requeue:
+ /*
+ * Timer is expired. Thus move it from tree to pending list
+ * again.
+ */
+ __remove_hrtimer(timer, base, timer->state, 0);
+ list_add_tail(&timer->cb_entry, &base->expired);
+#endif
+}
+
+/*
+ * The changes in mainline which removed the callback modes from
+ * hrtimer are not yet working with -rt. The non wakeup_process()
+ * based callbacks which involve sleeping locks need to be treated
+ * seperately.
+ */
+static void hrtimer_rt_run_pending(void)
+{
+ enum hrtimer_restart (*fn)(struct hrtimer *);
+ struct hrtimer_cpu_base *cpu_base;
+ struct hrtimer_clock_base *base;
+ struct hrtimer *timer;
+ int index, restart;
+
+ local_irq_disable();
+ cpu_base = &per_cpu(hrtimer_bases, smp_processor_id());
+
+ raw_spin_lock(&cpu_base->lock);
+
+ for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
+ base = &cpu_base->clock_base[index];
+
+ while (!list_empty(&base->expired)) {
+ timer = list_first_entry(&base->expired,
+ struct hrtimer, cb_entry);
+
+ /*
+ * Same as the above __run_hrtimer function
+ * just we run with interrupts enabled.
+ */
+ debug_hrtimer_deactivate(timer);
+ __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
+ timer_stats_account_hrtimer(timer);
+ fn = timer->function;
+
+ raw_spin_unlock_irq(&cpu_base->lock);
+ restart = fn(timer);
+ raw_spin_lock_irq(&cpu_base->lock);
+
+ hrtimer_rt_reprogram(restart, timer, base);
+ }
+ }
+
+ raw_spin_unlock_irq(&cpu_base->lock);
+
+ wake_up_timer_waiters(cpu_base);
+}
+
+static int hrtimer_rt_defer(struct hrtimer *timer)
+{
+ if (timer->irqsafe)
+ return 0;
+
+ __remove_hrtimer(timer, timer->base, timer->state, 0);
+ list_add_tail(&timer->cb_entry, &timer->base->expired);
+ return 1;
+}
+
+#else
+
+static inline void hrtimer_rt_run_pending(void)
+{
+ hrtimer_peek_ahead_timers();
+}
+
+static inline int hrtimer_rt_defer(struct hrtimer *timer) { return 0; }
+
+#endif
+
#ifdef CONFIG_HIGH_RES_TIMERS
/*
@@ -1283,7 +1512,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
{
struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
ktime_t expires_next, now, entry_time, delta;
- int i, retries = 0;
+ int i, retries = 0, raise = 0;
BUG_ON(!cpu_base->hres_active);
cpu_base->nr_events++;
@@ -1318,6 +1547,15 @@ retry:
timer = container_of(node, struct hrtimer, node);
+ trace_hrtimer_interrupt(raw_smp_processor_id(),
+ ktime_to_ns(ktime_sub(ktime_to_ns(timer->praecox) ?
+ timer->praecox : hrtimer_get_expires(timer),
+ basenow)),
+ current,
+ timer->function == hrtimer_wakeup ?
+ container_of(timer, struct hrtimer_sleeper,
+ timer)->task : NULL);
+
/*
* The immediate goal for using the softexpires is
* minimizing wakeups, not running timers at the
@@ -1343,7 +1581,10 @@ retry:
break;
}
- __run_hrtimer(timer, &basenow);
+ if (!hrtimer_rt_defer(timer))
+ __run_hrtimer(timer, &basenow);
+ else
+ raise = 1;
}
}
@@ -1358,7 +1599,7 @@ retry:
if (expires_next.tv64 == KTIME_MAX ||
!tick_program_event(expires_next, 0)) {
cpu_base->hang_detected = 0;
- return;
+ goto out;
}
/*
@@ -1402,6 +1643,9 @@ retry:
tick_program_event(expires_next, 1);
printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n",
ktime_to_ns(delta));
+out:
+ if (raise)
+ raise_softirq_irqoff(HRTIMER_SOFTIRQ);
}
/*
@@ -1437,40 +1681,16 @@ void hrtimer_peek_ahead_timers(void)
__hrtimer_peek_ahead_timers();
local_irq_restore(flags);
}
-
-static void run_hrtimer_softirq(struct softirq_action *h)
-{
- hrtimer_peek_ahead_timers();
-}
-
#else /* CONFIG_HIGH_RES_TIMERS */
static inline void __hrtimer_peek_ahead_timers(void) { }
#endif /* !CONFIG_HIGH_RES_TIMERS */
-/*
- * Called from timer softirq every jiffy, expire hrtimers:
- *
- * For HRT its the fall back code to run the softirq in the timer
- * softirq context in case the hrtimer initialization failed or has
- * not been done yet.
- */
-void hrtimer_run_pending(void)
-{
- if (hrtimer_hres_active())
- return;
- /*
- * This _is_ ugly: We have to check in the softirq context,
- * whether we can switch to highres and / or nohz mode. The
- * clocksource switch happens in the timer interrupt with
- * xtime_lock held. Notification from there only sets the
- * check bit in the tick_oneshot code, otherwise we might
- * deadlock vs. xtime_lock.
- */
- if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
- hrtimer_switch_to_hres();
+static void run_hrtimer_softirq(struct softirq_action *h)
+{
+ hrtimer_rt_run_pending();
}
/*
@@ -1481,11 +1701,18 @@ void hrtimer_run_queues(void)
struct timerqueue_node *node;
struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
struct hrtimer_clock_base *base;
- int index, gettime = 1;
+ int index, gettime = 1, raise = 0;
if (hrtimer_hres_active())
return;
+ /*
+ * Check whether we can switch to highres mode.
+ */
+ if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())
+ && hrtimer_switch_to_hres())
+ return;
+
for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
base = &cpu_base->clock_base[index];
if (!timerqueue_getnext(&base->active))
@@ -1506,10 +1733,16 @@ void hrtimer_run_queues(void)
hrtimer_get_expires_tv64(timer))
break;
- __run_hrtimer(timer, &base->softirq_time);
+ if (!hrtimer_rt_defer(timer))
+ __run_hrtimer(timer, &base->softirq_time);
+ else
+ raise = 1;
}
raw_spin_unlock(&cpu_base->lock);
}
+
+ if (raise)
+ raise_softirq_irqoff(HRTIMER_SOFTIRQ);
}
/*
@@ -1531,16 +1764,18 @@ static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
{
sl->timer.function = hrtimer_wakeup;
+ sl->timer.irqsafe = 1;
sl->task = task;
}
EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
-static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
+static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode,
+ unsigned long state)
{
hrtimer_init_sleeper(t, current);
do {
- set_current_state(TASK_INTERRUPTIBLE);
+ set_current_state(state);
hrtimer_start_expires(&t->timer, mode);
if (!hrtimer_active(&t->timer))
t->task = NULL;
@@ -1584,7 +1819,8 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
HRTIMER_MODE_ABS);
hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
- if (do_nanosleep(&t, HRTIMER_MODE_ABS))
+ /* cpu_chill() does not care about restart state. */
+ if (do_nanosleep(&t, HRTIMER_MODE_ABS, TASK_INTERRUPTIBLE))
goto out;
rmtp = restart->nanosleep.rmtp;
@@ -1601,8 +1837,10 @@ out:
return ret;
}
-long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
- const enum hrtimer_mode mode, const clockid_t clockid)
+static long
+__hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
+ const enum hrtimer_mode mode, const clockid_t clockid,
+ unsigned long state)
{
struct restart_block *restart;
struct hrtimer_sleeper t;
@@ -1615,7 +1853,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
hrtimer_init_on_stack(&t.timer, clockid, mode);
hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
- if (do_nanosleep(&t, mode))
+ if (do_nanosleep(&t, mode, state))
goto out;
/* Absolute timers do not update the rmtp value and restart: */
@@ -1642,6 +1880,12 @@ out:
return ret;
}
+long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
+ const enum hrtimer_mode mode, const clockid_t clockid)
+{
+ return __hrtimer_nanosleep(rqtp, rmtp, mode, clockid, TASK_INTERRUPTIBLE);
+}
+
SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
struct timespec __user *, rmtp)
{
@@ -1656,6 +1900,26 @@ SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Sleep for 1 ms in hope whoever holds what we want will let it go.
+ */
+void cpu_chill(void)
+{
+ struct timespec tu = {
+ .tv_nsec = NSEC_PER_MSEC,
+ };
+ unsigned int freeze_flag = current->flags & PF_NOFREEZE;
+
+ current->flags |= PF_NOFREEZE;
+ __hrtimer_nanosleep(&tu, NULL, HRTIMER_MODE_REL, CLOCK_MONOTONIC,
+ TASK_UNINTERRUPTIBLE);
+ if (!freeze_flag)
+ current->flags &= ~PF_NOFREEZE;
+}
+EXPORT_SYMBOL(cpu_chill);
+#endif
+
/*
* Functions related to boot-time initialization:
*/
@@ -1667,9 +1931,13 @@ static void init_hrtimers_cpu(int cpu)
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
cpu_base->clock_base[i].cpu_base = cpu_base;
timerqueue_init_head(&cpu_base->clock_base[i].active);
+ INIT_LIST_HEAD(&cpu_base->clock_base[i].expired);
}
hrtimer_init_hres(cpu_base);
+#ifdef CONFIG_PREEMPT_RT_BASE
+ init_waitqueue_head(&cpu_base->wait);
+#endif
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -1782,9 +2050,7 @@ void __init hrtimers_init(void)
hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
(void *)(long)smp_processor_id());
register_cpu_notifier(&hrtimers_nb);
-#ifdef CONFIG_HIGH_RES_TIMERS
open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
-#endif
}
/**
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 131ca17..7f50c55 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -132,6 +132,8 @@ static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
irqreturn_t
handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
{
+ struct pt_regs *regs = get_irq_regs();
+ u64 ip = regs ? instruction_pointer(regs) : 0;
irqreturn_t retval = IRQ_NONE;
unsigned int flags = 0, irq = desc->irq_data.irq;
@@ -172,7 +174,11 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
action = action->next;
} while (action);
- add_interrupt_randomness(irq, flags);
+#ifndef CONFIG_PREEMPT_RT_FULL
+ add_interrupt_randomness(irq, flags, ip);
+#else
+ desc->random_ip = ip;
+#endif
if (!noirqdebug)
note_interrupt(irq, desc, retval);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 4c84746..252bf10 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -22,6 +22,7 @@
#include "internals.h"
#ifdef CONFIG_IRQ_FORCED_THREADING
+# ifndef CONFIG_PREEMPT_RT_BASE
__read_mostly bool force_irqthreads;
static int __init setup_forced_irqthreads(char *arg)
@@ -30,6 +31,7 @@ static int __init setup_forced_irqthreads(char *arg)
return 0;
}
early_param("threadirqs", setup_forced_irqthreads);
+# endif
#endif
/**
@@ -162,6 +164,62 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
return ret;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void _irq_affinity_notify(struct irq_affinity_notify *notify);
+static struct task_struct *set_affinity_helper;
+static LIST_HEAD(affinity_list);
+static DEFINE_RAW_SPINLOCK(affinity_list_lock);
+
+static int set_affinity_thread(void *unused)
+{
+ while (1) {
+ struct irq_affinity_notify *notify;
+ int empty;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ raw_spin_lock_irq(&affinity_list_lock);
+ empty = list_empty(&affinity_list);
+ raw_spin_unlock_irq(&affinity_list_lock);
+
+ if (empty)
+ schedule();
+ if (kthread_should_stop())
+ break;
+ set_current_state(TASK_RUNNING);
+try_next:
+ notify = NULL;
+
+ raw_spin_lock_irq(&affinity_list_lock);
+ if (!list_empty(&affinity_list)) {
+ notify = list_first_entry(&affinity_list,
+ struct irq_affinity_notify, list);
+ list_del_init(&notify->list);
+ }
+ raw_spin_unlock_irq(&affinity_list_lock);
+
+ if (!notify)
+ continue;
+ _irq_affinity_notify(notify);
+ goto try_next;
+ }
+ return 0;
+}
+
+static void init_helper_thread(void)
+{
+ if (set_affinity_helper)
+ return;
+ set_affinity_helper = kthread_run(set_affinity_thread, NULL,
+ "affinity-cb");
+ WARN_ON(IS_ERR(set_affinity_helper));
+}
+#else
+
+static inline void init_helper_thread(void) { }
+
+#endif
+
int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
{
struct irq_chip *chip = irq_data_get_irq_chip(data);
@@ -180,7 +238,17 @@ int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
if (desc->affinity_notify) {
kref_get(&desc->affinity_notify->kref);
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ raw_spin_lock(&affinity_list_lock);
+ if (list_empty(&desc->affinity_notify->list))
+ list_add_tail(&affinity_list,
+ &desc->affinity_notify->list);
+ raw_spin_unlock(&affinity_list_lock);
+ wake_up_process(set_affinity_helper);
+#else
schedule_work(&desc->affinity_notify->work);
+#endif
}
irqd_set(data, IRQD_AFFINITY_SET);
@@ -221,10 +289,8 @@ int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
}
EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
-static void irq_affinity_notify(struct work_struct *work)
+static void _irq_affinity_notify(struct irq_affinity_notify *notify)
{
- struct irq_affinity_notify *notify =
- container_of(work, struct irq_affinity_notify, work);
struct irq_desc *desc = irq_to_desc(notify->irq);
cpumask_var_t cpumask;
unsigned long flags;
@@ -246,6 +312,13 @@ out:
kref_put(&notify->kref, notify->release);
}
+static void irq_affinity_notify(struct work_struct *work)
+{
+ struct irq_affinity_notify *notify =
+ container_of(work, struct irq_affinity_notify, work);
+ _irq_affinity_notify(notify);
+}
+
/**
* irq_set_affinity_notifier - control notification of IRQ affinity changes
* @irq: Interrupt for which to enable/disable notification
@@ -275,6 +348,8 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
notify->irq = irq;
kref_init(&notify->kref);
INIT_WORK(&notify->work, irq_affinity_notify);
+ INIT_LIST_HEAD(&notify->list);
+ init_helper_thread();
}
raw_spin_lock_irqsave(&desc->lock, flags);
@@ -781,7 +856,15 @@ irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
local_bh_disable();
ret = action->thread_fn(action->irq, action->dev_id);
irq_finalize_oneshot(desc, action);
- local_bh_enable();
+ /*
+ * Interrupts which have real time requirements can be set up
+ * to avoid softirq processing in the thread handler. This is
+ * safe as these interrupts do not raise soft interrupts.
+ */
+ if (irq_settings_no_softirq_call(desc))
+ _local_bh_enable();
+ else
+ local_bh_enable();
return ret;
}
@@ -864,6 +947,12 @@ static int irq_thread(void *data)
if (!noirqdebug)
note_interrupt(action->irq, desc, action_ret);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ migrate_disable();
+ add_interrupt_randomness(action->irq, 0,
+ desc->random_ip ^ (unsigned long) action);
+ migrate_enable();
+#endif
wake_threads_waitq(desc);
}
@@ -1126,6 +1215,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
}
+ if (new->flags & IRQF_NO_SOFTIRQ_CALL)
+ irq_settings_set_no_softirq_call(desc);
+
/* Set default affinity mask once everything is setup */
setup_affinity(irq, desc, mask);
diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h
index 1162f10..0d2c381 100644
--- a/kernel/irq/settings.h
+++ b/kernel/irq/settings.h
@@ -14,6 +14,7 @@ enum {
_IRQ_NO_BALANCING = IRQ_NO_BALANCING,
_IRQ_NESTED_THREAD = IRQ_NESTED_THREAD,
_IRQ_PER_CPU_DEVID = IRQ_PER_CPU_DEVID,
+ _IRQ_NO_SOFTIRQ_CALL = IRQ_NO_SOFTIRQ_CALL,
_IRQF_MODIFY_MASK = IRQF_MODIFY_MASK,
};
@@ -26,6 +27,7 @@ enum {
#define IRQ_NOAUTOEN GOT_YOU_MORON
#define IRQ_NESTED_THREAD GOT_YOU_MORON
#define IRQ_PER_CPU_DEVID GOT_YOU_MORON
+#define IRQ_NO_SOFTIRQ_CALL GOT_YOU_MORON
#undef IRQF_MODIFY_MASK
#define IRQF_MODIFY_MASK GOT_YOU_MORON
@@ -36,6 +38,16 @@ irq_settings_clr_and_set(struct irq_desc *desc, u32 clr, u32 set)
desc->status_use_accessors |= (set & _IRQF_MODIFY_MASK);
}
+static inline bool irq_settings_no_softirq_call(struct irq_desc *desc)
+{
+ return desc->status_use_accessors & _IRQ_NO_SOFTIRQ_CALL;
+}
+
+static inline void irq_settings_set_no_softirq_call(struct irq_desc *desc)
+{
+ desc->status_use_accessors |= _IRQ_NO_SOFTIRQ_CALL;
+}
+
static inline bool irq_settings_is_per_cpu(struct irq_desc *desc)
{
return desc->status_use_accessors & _IRQ_PER_CPU;
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 7b5f012..e5a309a 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -340,6 +340,10 @@ MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true");
static int __init irqfixup_setup(char *str)
{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ pr_warn("irqfixup boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+ return 1;
+#endif
irqfixup = 1;
printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
printk(KERN_WARNING "This may impact system performance.\n");
@@ -352,6 +356,10 @@ module_param(irqfixup, int, 0644);
static int __init irqpoll_setup(char *str)
{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ pr_warn("irqpoll boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+ return 1;
+#endif
irqfixup = 2;
printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
"enabled\n");
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 55fcce6..35d21f9 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -20,6 +20,9 @@
static DEFINE_PER_CPU(struct llist_head, irq_work_list);
+#ifdef CONFIG_PREEMPT_RT_FULL
+static DEFINE_PER_CPU(struct llist_head, hirq_work_list);
+#endif
static DEFINE_PER_CPU(int, irq_work_raised);
/*
@@ -48,7 +51,11 @@ static bool irq_work_claim(struct irq_work *work)
return true;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+void arch_irq_work_raise(void)
+#else
void __weak arch_irq_work_raise(void)
+#endif
{
/*
* Lame architectures will get the timer tick callback
@@ -70,8 +77,12 @@ void irq_work_queue(struct irq_work *work)
/* Queue the entry and raise the IPI if needed. */
preempt_disable();
- llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
-
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (work->flags & IRQ_WORK_HARD_IRQ)
+ llist_add(&work->llnode, &__get_cpu_var(hirq_work_list));
+ else
+#endif
+ llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
/*
* If the work is not "lazy" or the tick is stopped, raise the irq
* work interrupt (if supported by the arch), otherwise, just wait
@@ -115,12 +126,18 @@ static void __irq_work_run(void)
__this_cpu_write(irq_work_raised, 0);
barrier();
- this_list = &__get_cpu_var(irq_work_list);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (in_irq())
+ this_list = &__get_cpu_var(hirq_work_list);
+ else
+#endif
+ this_list = &__get_cpu_var(irq_work_list);
if (llist_empty(this_list))
return;
+#ifndef CONFIG_PREEMPT_RT_FULL
BUG_ON(!irqs_disabled());
-
+#endif
llnode = llist_del_all(this_list);
while (llnode != NULL) {
work = llist_entry(llnode, struct irq_work, llnode);
@@ -152,7 +169,9 @@ static void __irq_work_run(void)
*/
void irq_work_run(void)
{
+#ifndef CONFIG_PREEMPT_RT_FULL
BUG_ON(!in_irq());
+#endif
__irq_work_run();
}
EXPORT_SYMBOL_GPL(irq_work_run);
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 8d262b4..d051390 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -213,6 +213,7 @@ again:
/* We are sharing ->siglock with it_real_fn() */
if (hrtimer_try_to_cancel(timer) < 0) {
spin_unlock_irq(&tsk->sighand->siglock);
+ hrtimer_wait_for_timer(&tsk->signal->real_timer);
goto again;
}
expires = timeval_to_ktime(value->it_value);
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 9659d38..b66ab9e 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -132,6 +132,15 @@ KERNEL_ATTR_RO(vmcoreinfo);
#endif /* CONFIG_KEXEC */
+#if defined(CONFIG_PREEMPT_RT_FULL)
+static ssize_t realtime_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", 1);
+}
+KERNEL_ATTR_RO(realtime);
+#endif
+
/* whether file capabilities are enabled */
static ssize_t fscaps_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
@@ -197,6 +206,9 @@ static struct attribute * kernel_attrs[] = {
&vmcoreinfo_attr.attr,
#endif
&rcu_expedited_attr.attr,
+#ifdef CONFIG_PREEMPT_RT_FULL
+ &realtime_attr.attr,
+#endif
NULL
};
diff --git a/kernel/lglock.c b/kernel/lglock.c
index 86ae2ae..f2356df 100644
--- a/kernel/lglock.c
+++ b/kernel/lglock.c
@@ -4,6 +4,15 @@
#include <linux/cpu.h>
#include <linux/string.h>
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define lg_lock_ptr arch_spinlock_t
+# define lg_do_lock(l) arch_spin_lock(l)
+# define lg_do_unlock(l) arch_spin_unlock(l)
+#else
+# define lg_lock_ptr struct rt_mutex
+# define lg_do_lock(l) __rt_spin_lock(l)
+# define lg_do_unlock(l) __rt_spin_unlock(l)
+#endif
/*
* Note there is no uninit, so lglocks cannot be defined in
* modules (but it's fine to use them from there)
@@ -12,51 +21,60 @@
void lg_lock_init(struct lglock *lg, char *name)
{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ int i;
+
+ for_each_possible_cpu(i) {
+ struct rt_mutex *lock = per_cpu_ptr(lg->lock, i);
+
+ rt_mutex_init(lock);
+ }
+#endif
LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
}
EXPORT_SYMBOL(lg_lock_init);
void lg_local_lock(struct lglock *lg)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
- preempt_disable();
+ migrate_disable();
lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
lock = this_cpu_ptr(lg->lock);
- arch_spin_lock(lock);
+ lg_do_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock);
void lg_local_unlock(struct lglock *lg)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
lock = this_cpu_ptr(lg->lock);
- arch_spin_unlock(lock);
- preempt_enable();
+ lg_do_unlock(lock);
+ migrate_enable();
}
EXPORT_SYMBOL(lg_local_unlock);
void lg_local_lock_cpu(struct lglock *lg, int cpu)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
- preempt_disable();
+ preempt_disable_nort();
lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
lock = per_cpu_ptr(lg->lock, cpu);
- arch_spin_lock(lock);
+ lg_do_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock_cpu);
void lg_local_unlock_cpu(struct lglock *lg, int cpu)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
lock = per_cpu_ptr(lg->lock, cpu);
- arch_spin_unlock(lock);
- preempt_enable();
+ lg_do_unlock(lock);
+ preempt_enable_nort();
}
EXPORT_SYMBOL(lg_local_unlock_cpu);
@@ -64,12 +82,12 @@ void lg_global_lock(struct lglock *lg)
{
int i;
- preempt_disable();
+ preempt_disable_nort();
lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
for_each_possible_cpu(i) {
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock = per_cpu_ptr(lg->lock, i);
- arch_spin_lock(lock);
+ lg_do_lock(lock);
}
}
EXPORT_SYMBOL(lg_global_lock);
@@ -80,10 +98,10 @@ void lg_global_unlock(struct lglock *lg)
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
for_each_possible_cpu(i) {
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock = per_cpu_ptr(lg->lock, i);
- arch_spin_unlock(lock);
+ lg_do_unlock(lock);
}
- preempt_enable();
+ preempt_enable_nort();
}
EXPORT_SYMBOL(lg_global_unlock);
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index e16c45b..b74f7a5 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3541,6 +3541,7 @@ static void check_flags(unsigned long flags)
}
}
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* We dont accurately track softirq state in e.g.
* hardirq contexts (such as on 4KSTACKS), so only
@@ -3555,6 +3556,7 @@ static void check_flags(unsigned long flags)
DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled);
}
}
+#endif
if (!debug_locks)
print_irqtrace_events(current);
diff --git a/kernel/panic.c b/kernel/panic.c
index b6c482c..936d00f 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -368,9 +368,11 @@ static u64 oops_id;
static int init_oops_id(void)
{
+#ifndef CONFIG_PREEMPT_RT_FULL
if (!oops_id)
get_random_bytes(&oops_id, sizeof(oops_id));
else
+#endif
oops_id++;
return 0;
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index c7f31aa..4bf82f8 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -3,6 +3,7 @@
*/
#include <linux/sched.h>
+#include <linux/sched/rt.h>
#include <linux/posix-timers.h>
#include <linux/errno.h>
#include <linux/math64.h>
@@ -663,7 +664,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int flags,
/*
* Disarm any old timer after extracting its expiry time.
*/
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
ret = 0;
old_incr = timer->it.cpu.incr;
@@ -1110,7 +1111,7 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
/*
* Now re-arm for the new expiry time.
*/
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
arm_timer(timer);
spin_unlock(&p->sighand->siglock);
@@ -1177,10 +1178,11 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
sig = tsk->signal;
if (sig->cputimer.running) {
struct task_cputime group_sample;
+ unsigned long flags;
- raw_spin_lock(&sig->cputimer.lock);
+ raw_spin_lock_irqsave(&sig->cputimer.lock, flags);
group_sample = sig->cputimer.cputime;
- raw_spin_unlock(&sig->cputimer.lock);
+ raw_spin_unlock_irqrestore(&sig->cputimer.lock, flags);
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;
@@ -1194,13 +1196,13 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
* already updated our counts. We need to check if any timers fire now.
* Interrupts are disabled.
*/
-void run_posix_cpu_timers(struct task_struct *tsk)
+static void __run_posix_cpu_timers(struct task_struct *tsk)
{
LIST_HEAD(firing);
struct k_itimer *timer, *next;
unsigned long flags;
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
/*
* The fast path checks that there are no expired thread or thread
@@ -1265,6 +1267,190 @@ void run_posix_cpu_timers(struct task_struct *tsk)
posix_cpu_timer_kick_nohz();
}
+#ifdef CONFIG_PREEMPT_RT_BASE
+#include <linux/kthread.h>
+#include <linux/cpu.h>
+DEFINE_PER_CPU(struct task_struct *, posix_timer_task);
+DEFINE_PER_CPU(struct task_struct *, posix_timer_tasklist);
+
+static int posix_cpu_timers_thread(void *data)
+{
+ int cpu = (long)data;
+
+ BUG_ON(per_cpu(posix_timer_task,cpu) != current);
+
+ while (!kthread_should_stop()) {
+ struct task_struct *tsk = NULL;
+ struct task_struct *next = NULL;
+
+ if (cpu_is_offline(cpu))
+ goto wait_to_die;
+
+ /* grab task list */
+ raw_local_irq_disable();
+ tsk = per_cpu(posix_timer_tasklist, cpu);
+ per_cpu(posix_timer_tasklist, cpu) = NULL;
+ raw_local_irq_enable();
+
+ /* its possible the list is empty, just return */
+ if (!tsk) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ continue;
+ }
+
+ /* Process task list */
+ while (1) {
+ /* save next */
+ next = tsk->posix_timer_list;
+
+ /* run the task timers, clear its ptr and
+ * unreference it
+ */
+ __run_posix_cpu_timers(tsk);
+ tsk->posix_timer_list = NULL;
+ put_task_struct(tsk);
+
+ /* check if this is the last on the list */
+ if (next == tsk)
+ break;
+ tsk = next;
+ }
+ }
+ return 0;
+
+wait_to_die:
+ /* Wait for kthread_stop */
+ set_current_state(TASK_INTERRUPTIBLE);
+ while (!kthread_should_stop()) {
+ schedule();
+ set_current_state(TASK_INTERRUPTIBLE);
+ }
+ __set_current_state(TASK_RUNNING);
+ return 0;
+}
+
+static inline int __fastpath_timer_check(struct task_struct *tsk)
+{
+ /* tsk == current, ensure it is safe to use ->signal/sighand */
+ if (unlikely(tsk->exit_state))
+ return 0;
+
+ if (!task_cputime_zero(&tsk->cputime_expires))
+ return 1;
+
+ if (!task_cputime_zero(&tsk->signal->cputime_expires))
+ return 1;
+
+ return 0;
+}
+
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ unsigned long cpu = smp_processor_id();
+ struct task_struct *tasklist;
+
+ BUG_ON(!irqs_disabled());
+ if(!per_cpu(posix_timer_task, cpu))
+ return;
+ /* get per-cpu references */
+ tasklist = per_cpu(posix_timer_tasklist, cpu);
+
+ /* check to see if we're already queued */
+ if (!tsk->posix_timer_list && __fastpath_timer_check(tsk)) {
+ get_task_struct(tsk);
+ if (tasklist) {
+ tsk->posix_timer_list = tasklist;
+ } else {
+ /*
+ * The list is terminated by a self-pointing
+ * task_struct
+ */
+ tsk->posix_timer_list = tsk;
+ }
+ per_cpu(posix_timer_tasklist, cpu) = tsk;
+
+ wake_up_process(per_cpu(posix_timer_task, cpu));
+ }
+}
+
+/*
+ * posix_cpu_thread_call - callback that gets triggered when a CPU is added.
+ * Here we can start up the necessary migration thread for the new CPU.
+ */
+static int posix_cpu_thread_call(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ int cpu = (long)hcpu;
+ struct task_struct *p;
+ struct sched_param param;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ p = kthread_create(posix_cpu_timers_thread, hcpu,
+ "posixcputmr/%d",cpu);
+ if (IS_ERR(p))
+ return NOTIFY_BAD;
+ p->flags |= PF_NOFREEZE;
+ kthread_bind(p, cpu);
+ /* Must be high prio to avoid getting starved */
+ param.sched_priority = MAX_RT_PRIO-1;
+ sched_setscheduler(p, SCHED_FIFO, &param);
+ per_cpu(posix_timer_task,cpu) = p;
+ break;
+ case CPU_ONLINE:
+ /* Strictly unneccessary, as first user will wake it. */
+ wake_up_process(per_cpu(posix_timer_task,cpu));
+ break;
+#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_UP_CANCELED:
+ /* Unbind it from offline cpu so it can run. Fall thru. */
+ kthread_bind(per_cpu(posix_timer_task, cpu),
+ cpumask_any(cpu_online_mask));
+ kthread_stop(per_cpu(posix_timer_task,cpu));
+ per_cpu(posix_timer_task,cpu) = NULL;
+ break;
+ case CPU_DEAD:
+ kthread_stop(per_cpu(posix_timer_task,cpu));
+ per_cpu(posix_timer_task,cpu) = NULL;
+ break;
+#endif
+ }
+ return NOTIFY_OK;
+}
+
+/* Register at highest priority so that task migration (migrate_all_tasks)
+ * happens before everything else.
+ */
+static struct notifier_block posix_cpu_thread_notifier = {
+ .notifier_call = posix_cpu_thread_call,
+ .priority = 10
+};
+
+static int __init posix_cpu_thread_init(void)
+{
+ void *hcpu = (void *)(long)smp_processor_id();
+ /* Start one for boot CPU. */
+ unsigned long cpu;
+
+ /* init the per-cpu posix_timer_tasklets */
+ for_each_possible_cpu(cpu)
+ per_cpu(posix_timer_tasklist, cpu) = NULL;
+
+ posix_cpu_thread_call(&posix_cpu_thread_notifier, CPU_UP_PREPARE, hcpu);
+ posix_cpu_thread_call(&posix_cpu_thread_notifier, CPU_ONLINE, hcpu);
+ register_cpu_notifier(&posix_cpu_thread_notifier);
+ return 0;
+}
+early_initcall(posix_cpu_thread_init);
+#else /* CONFIG_PREEMPT_RT_BASE */
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ __run_posix_cpu_timers(tsk);
+}
+#endif /* CONFIG_PREEMPT_RT_BASE */
+
/*
* Set one of the process-wide special case CPU timers or RLIMIT_CPU.
* The tsk->sighand->siglock must be held by the caller.
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 424c2d4..a22b931 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -497,6 +497,7 @@ static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
static struct pid *good_sigevent(sigevent_t * event)
{
struct task_struct *rtn = current->group_leader;
+ int sig = event->sigev_signo;
if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
(!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
@@ -505,7 +506,8 @@ static struct pid *good_sigevent(sigevent_t * event)
return NULL;
if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
- ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
+ (sig <= 0 || sig > SIGRTMAX || sig_kernel_only(sig) ||
+ sig_kernel_coredump(sig)))
return NULL;
return task_pid(rtn);
@@ -816,6 +818,20 @@ SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
return overrun;
}
+/*
+ * Protected by RCU!
+ */
+static void timer_wait_for_callback(struct k_clock *kc, struct k_itimer *timr)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (kc->timer_set == common_timer_set)
+ hrtimer_wait_for_timer(&timr->it.real.timer);
+ else
+ /* FIXME: Whacky hack for posix-cpu-timers */
+ schedule_timeout(1);
+#endif
+}
+
/* Set a POSIX.1b interval timer. */
/* timr->it_lock is taken. */
static int
@@ -893,6 +909,7 @@ retry:
if (!timr)
return -EINVAL;
+ rcu_read_lock();
kc = clockid_to_kclock(timr->it_clock);
if (WARN_ON_ONCE(!kc || !kc->timer_set))
error = -EINVAL;
@@ -901,9 +918,12 @@ retry:
unlock_timer(timr, flag);
if (error == TIMER_RETRY) {
+ timer_wait_for_callback(kc, timr);
rtn = NULL; // We already got the old time...
+ rcu_read_unlock();
goto retry;
}
+ rcu_read_unlock();
if (old_setting && !error &&
copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
@@ -941,10 +961,15 @@ retry_delete:
if (!timer)
return -EINVAL;
+ rcu_read_lock();
if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
+ timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
+ timer);
+ rcu_read_unlock();
goto retry_delete;
}
+ rcu_read_unlock();
spin_lock(&current->sighand->siglock);
list_del(&timer->list);
@@ -970,8 +995,18 @@ static void itimer_delete(struct k_itimer *timer)
retry_delete:
spin_lock_irqsave(&timer->it_lock, flags);
+ /* On RT we can race with a deletion */
+ if (!timer->it_signal) {
+ unlock_timer(timer, flags);
+ return;
+ }
+
if (timer_delete_hook(timer) == TIMER_RETRY) {
+ rcu_read_lock();
unlock_timer(timer, flags);
+ timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
+ timer);
+ rcu_read_unlock();
goto retry_delete;
}
list_del(&timer->list);
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 0121dab..d26958b 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -275,6 +275,8 @@ static int create_image(int platform_mode)
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (error) {
printk(KERN_ERR "PM: Some system devices failed to power down, "
@@ -302,6 +304,7 @@ static int create_image(int platform_mode)
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -427,6 +430,7 @@ static int resume_target_kernel(bool platform_mode)
goto Enable_cpus;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
error = syscore_suspend();
if (error)
@@ -460,6 +464,7 @@ static int resume_target_kernel(bool platform_mode)
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -542,6 +547,7 @@ int hibernation_platform_enter(void)
goto Platform_finish;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
syscore_suspend();
if (pm_wakeup_pending()) {
error = -EAGAIN;
@@ -554,6 +560,7 @@ int hibernation_platform_enter(void)
Power_up:
syscore_resume();
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
enable_nonboot_cpus();
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 62ee437..e6703bb 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -218,6 +218,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (!error) {
*wakeup = pm_wakeup_pending();
@@ -228,6 +230,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
syscore_resume();
}
+ system_state = SYSTEM_RUNNING;
+
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index c59896c..981ff61 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1029,6 +1029,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
{
char *text;
int len = 0;
+ int attempts = 0;
text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
if (!text)
@@ -1040,7 +1041,14 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
u64 seq;
u32 idx;
enum log_flags prev;
-
+ int num_msg;
+try_again:
+ attempts++;
+ if (attempts > 10) {
+ len = -EBUSY;
+ goto out;
+ }
+ num_msg = 0;
if (clear_seq < log_first_seq) {
/* messages are gone, move to first available one */
clear_seq = log_first_seq;
@@ -1061,6 +1069,14 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
prev = msg->flags;
idx = log_next(idx);
seq++;
+ num_msg++;
+ if (num_msg > 5) {
+ num_msg = 0;
+ raw_spin_unlock_irq(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
+ if (clear_seq < log_first_seq)
+ goto try_again;
+ }
}
/* move first record forward until length fits into the buffer */
@@ -1074,6 +1090,14 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
prev = msg->flags;
idx = log_next(idx);
seq++;
+ num_msg++;
+ if (num_msg > 5) {
+ num_msg = 0;
+ raw_spin_unlock_irq(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
+ if (clear_seq < log_first_seq)
+ goto try_again;
+ }
}
/* last message fitting into this dump */
@@ -1114,6 +1138,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
clear_seq = log_next_seq;
clear_idx = log_next_idx;
}
+out:
raw_spin_unlock_irq(&logbuf_lock);
kfree(text);
@@ -1271,6 +1296,7 @@ static void call_console_drivers(int level, const char *text, size_t len)
if (!console_drivers)
return;
+ migrate_disable();
for_each_console(con) {
if (exclusive_console && con != exclusive_console)
continue;
@@ -1283,6 +1309,7 @@ static void call_console_drivers(int level, const char *text, size_t len)
continue;
con->write(con, text, len);
}
+ migrate_enable();
}
/*
@@ -1342,12 +1369,18 @@ static inline int can_use_console(unsigned int cpu)
* interrupts disabled. It should return with 'lockbuf_lock'
* released but interrupts still disabled.
*/
-static int console_trylock_for_printk(unsigned int cpu)
+static int console_trylock_for_printk(unsigned int cpu, unsigned long flags)
__releases(&logbuf_lock)
{
int retval = 0, wake = 0;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ int lock = !early_boot_irqs_disabled && !irqs_disabled_flags(flags) &&
+ (preempt_count() <= 1);
+#else
+ int lock = 1;
+#endif
- if (console_trylock()) {
+ if (lock && console_trylock()) {
retval = 1;
/*
@@ -1487,6 +1520,62 @@ static size_t cont_print_text(char *text, size_t size)
return textlen;
}
+#ifdef CONFIG_EARLY_PRINTK
+struct console *early_console;
+
+void early_vprintk(const char *fmt, va_list ap)
+{
+ if (early_console) {
+ char buf[512];
+ int n = vscnprintf(buf, sizeof(buf), fmt, ap);
+
+ early_console->write(early_console, buf, n);
+ }
+}
+
+asmlinkage void early_printk(const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ early_vprintk(fmt, ap);
+ va_end(ap);
+}
+
+/*
+ * This is independent of any log levels - a global
+ * kill switch that turns off all of printk.
+ *
+ * Used by the NMI watchdog if early-printk is enabled.
+ */
+static bool __read_mostly printk_killswitch;
+
+static int __init force_early_printk_setup(char *str)
+{
+ printk_killswitch = true;
+ return 0;
+}
+early_param("force_early_printk", force_early_printk_setup);
+
+void printk_kill(void)
+{
+ printk_killswitch = true;
+}
+
+static int forced_early_printk(const char *fmt, va_list ap)
+{
+ if (!printk_killswitch)
+ return 0;
+ early_vprintk(fmt, ap);
+ return 1;
+}
+#else
+static inline int forced_early_printk(const char *fmt, va_list ap)
+{
+ return 0;
+}
+#endif
+
asmlinkage int vprintk_emit(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args)
@@ -1500,6 +1589,13 @@ asmlinkage int vprintk_emit(int facility, int level,
int this_cpu;
int printed_len = 0;
+ /*
+ * Fall back to early_printk if a debugging subsystem has
+ * killed printk output
+ */
+ if (unlikely(forced_early_printk(fmt, args)))
+ return 1;
+
boot_delay_msec(level);
printk_delay();
@@ -1619,8 +1715,15 @@ asmlinkage int vprintk_emit(int facility, int level,
* The console_trylock_for_printk() function will release 'logbuf_lock'
* regardless of whether it actually gets the console semaphore or not.
*/
- if (console_trylock_for_printk(this_cpu))
+ if (console_trylock_for_printk(this_cpu, flags)) {
+#ifndef CONFIG_PREEMPT_RT_FULL
console_unlock();
+#else
+ raw_local_irq_restore(flags);
+ console_unlock();
+ raw_local_irq_save(flags);
+#endif
+ }
lockdep_on();
out_restore_irqs:
@@ -1722,29 +1825,6 @@ static size_t cont_print_text(char *text, size_t size) { return 0; }
#endif /* CONFIG_PRINTK */
-#ifdef CONFIG_EARLY_PRINTK
-struct console *early_console;
-
-void early_vprintk(const char *fmt, va_list ap)
-{
- if (early_console) {
- char buf[512];
- int n = vscnprintf(buf, sizeof(buf), fmt, ap);
-
- early_console->write(early_console, buf, n);
- }
-}
-
-asmlinkage void early_printk(const char *fmt, ...)
-{
- va_list ap;
-
- va_start(ap, fmt);
- early_vprintk(fmt, ap);
- va_end(ap);
-}
-#endif
-
static int __add_preferred_console(char *name, int idx, char *options,
char *brl_options)
{
@@ -1985,11 +2065,16 @@ static void console_cont_flush(char *text, size_t size)
goto out;
len = cont_print_text(text, size);
+#ifndef CONFIG_PREEMPT_RT_FULL
raw_spin_unlock(&logbuf_lock);
stop_critical_timings();
call_console_drivers(cont.level, text, len);
start_critical_timings();
local_irq_restore(flags);
+#else
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+ call_console_drivers(cont.level, text, len);
+#endif
return;
out:
raw_spin_unlock_irqrestore(&logbuf_lock, flags);
@@ -2072,12 +2157,17 @@ skip:
console_idx = log_next(console_idx);
console_seq++;
console_prev = msg->flags;
- raw_spin_unlock(&logbuf_lock);
+#ifndef CONFIG_PREEMPT_RT_FULL
+ raw_spin_unlock(&logbuf_lock);
stop_critical_timings(); /* don't trace print latency */
call_console_drivers(level, text, len);
start_critical_timings();
local_irq_restore(flags);
+#else
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+ call_console_drivers(level, text, len);
+#endif
}
console_locked = 0;
mutex_release(&console_lock_dep_map, 1, _RET_IP_);
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 1f4bcb3..fddaf65 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -135,7 +135,12 @@ static bool ptrace_freeze_traced(struct task_struct *task)
spin_lock_irq(&task->sighand->siglock);
if (task_is_traced(task) && !__fatal_signal_pending(task)) {
- task->state = __TASK_TRACED;
+ raw_spin_lock_irq(&task->pi_lock);
+ if (task->state & __TASK_TRACED)
+ task->state = __TASK_TRACED;
+ else
+ task->saved_state = __TASK_TRACED;
+ raw_spin_unlock_irq(&task->pi_lock);
ret = true;
}
spin_unlock_irq(&task->sighand->siglock);
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index b02a339..7e1dd3e 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -129,6 +129,7 @@ int notrace debug_lockdep_rcu_enabled(void)
}
EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
+#ifndef CONFIG_PREEMPT_RT_FULL
/**
* rcu_read_lock_bh_held() - might we be in RCU-bh read-side critical section?
*
@@ -155,6 +156,7 @@ int rcu_read_lock_bh_held(void)
return in_softirq() || irqs_disabled();
}
EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
+#endif
#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index 9ed6075..f202b26 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -369,6 +369,7 @@ void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
}
EXPORT_SYMBOL_GPL(call_rcu_sched);
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Post an RCU bottom-half callback to be invoked after any subsequent
* quiescent state.
@@ -378,6 +379,7 @@ void call_rcu_bh(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
__call_rcu(head, func, &rcu_bh_ctrlblk);
}
EXPORT_SYMBOL_GPL(call_rcu_bh);
+#endif
void rcu_init(void)
{
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 32618b3..507fab1 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -55,6 +55,11 @@
#include <linux/random.h>
#include <linux/ftrace_event.h>
#include <linux/suspend.h>
+#include <linux/delay.h>
+#include <linux/gfp.h>
+#include <linux/oom.h>
+#include <linux/smpboot.h>
+#include "time/tick-internal.h"
#include "rcutree.h"
#include <trace/events/rcu.h>
@@ -145,8 +150,6 @@ EXPORT_SYMBOL_GPL(rcu_scheduler_active);
*/
static int rcu_scheduler_fully_active __read_mostly;
-#ifdef CONFIG_RCU_BOOST
-
/*
* Control variables for per-CPU and per-rcu_node kthreads. These
* handle all flavors of RCU.
@@ -156,8 +159,6 @@ DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
DEFINE_PER_CPU(char, rcu_cpu_has_work);
-#endif /* #ifdef CONFIG_RCU_BOOST */
-
static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu);
static void invoke_rcu_core(void);
static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp);
@@ -199,6 +200,19 @@ void rcu_sched_qs(int cpu)
rdp->passed_quiesce = 1;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void rcu_preempt_qs(int cpu);
+
+void rcu_bh_qs(int cpu)
+{
+ unsigned long flags;
+
+ /* Callers to this function, rcu_preempt_qs(), must disable irqs. */
+ local_irq_save(flags);
+ rcu_preempt_qs(cpu);
+ local_irq_restore(flags);
+}
+#else
void rcu_bh_qs(int cpu)
{
struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu);
@@ -207,6 +221,7 @@ void rcu_bh_qs(int cpu)
trace_rcu_grace_period(TPS("rcu_bh"), rdp->gpnum, TPS("cpuqs"));
rdp->passed_quiesce = 1;
}
+#endif
/*
* Note a context switch. This is a quiescent state for RCU-sched,
@@ -263,6 +278,7 @@ long rcu_batches_completed_sched(void)
}
EXPORT_SYMBOL_GPL(rcu_batches_completed_sched);
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Return the number of RCU BH batches processed thus far for debug & stats.
*/
@@ -280,6 +296,7 @@ void rcu_bh_force_quiescent_state(void)
force_quiescent_state(&rcu_bh_state);
}
EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state);
+#endif
/*
* Record the number of times rcutorture tests have been initiated and
@@ -1471,7 +1488,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
/* Handle grace-period start. */
for (;;) {
- wait_event_interruptible(rsp->gp_wq,
+ swait_event_interruptible(rsp->gp_wq,
rsp->gp_flags &
RCU_GP_FLAG_INIT);
if ((rsp->gp_flags & RCU_GP_FLAG_INIT) &&
@@ -1490,7 +1507,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
}
for (;;) {
rsp->jiffies_force_qs = jiffies + j;
- ret = wait_event_interruptible_timeout(rsp->gp_wq,
+ ret = swait_event_interruptible_timeout(rsp->gp_wq,
(rsp->gp_flags & RCU_GP_FLAG_FQS) ||
(!ACCESS_ONCE(rnp->qsmask) &&
!rcu_preempt_blocked_readers_cgp(rnp)),
@@ -1528,7 +1545,7 @@ static void rsp_wakeup(struct irq_work *work)
struct rcu_state *rsp = container_of(work, struct rcu_state, wakeup_work);
/* Wake up rcu_gp_kthread() to start the grace period. */
- wake_up(&rsp->gp_wq);
+ swait_wake(&rsp->gp_wq);
}
/*
@@ -1602,7 +1619,7 @@ static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)
{
WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
raw_spin_unlock_irqrestore(&rcu_get_root(rsp)->lock, flags);
- wake_up(&rsp->gp_wq); /* Memory barrier implied by wake_up() path. */
+ swait_wake(&rsp->gp_wq); /* Memory barrier implied by wake_up() path. */
}
/*
@@ -2172,7 +2189,8 @@ static void force_quiescent_state(struct rcu_state *rsp)
}
rsp->gp_flags |= RCU_GP_FLAG_FQS;
raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
- wake_up(&rsp->gp_wq); /* Memory barrier implied by wake_up() path. */
+ /* Memory barrier implied by wake_up() path. */
+ swait_wake(&rsp->gp_wq);
}
/*
@@ -2209,16 +2227,14 @@ __rcu_process_callbacks(struct rcu_state *rsp)
/*
* Do RCU core processing for the current CPU.
*/
-static void rcu_process_callbacks(struct softirq_action *unused)
+static void rcu_process_callbacks(void)
{
struct rcu_state *rsp;
if (cpu_is_offline(smp_processor_id()))
return;
- trace_rcu_utilization(TPS("Start RCU core"));
for_each_rcu_flavor(rsp)
__rcu_process_callbacks(rsp);
- trace_rcu_utilization(TPS("End RCU core"));
}
/*
@@ -2232,18 +2248,105 @@ static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
{
if (unlikely(!ACCESS_ONCE(rcu_scheduler_fully_active)))
return;
- if (likely(!rsp->boost)) {
- rcu_do_batch(rsp, rdp);
+ rcu_do_batch(rsp, rdp);
+}
+
+static void rcu_wake_cond(struct task_struct *t, int status)
+{
+ /*
+ * If the thread is yielding, only wake it when this
+ * is invoked from idle
+ */
+ if (t && (status != RCU_KTHREAD_YIELDING || is_idle_task(current)))
+ wake_up_process(t);
+}
+
+/*
+ * Wake up this CPU's rcuc kthread to do RCU core processing.
+ */
+static void invoke_rcu_core(void)
+{
+ unsigned long flags;
+ struct task_struct *t;
+
+ if (!cpu_online(smp_processor_id()))
return;
+ local_irq_save(flags);
+ __this_cpu_write(rcu_cpu_has_work, 1);
+ t = __this_cpu_read(rcu_cpu_kthread_task);
+ if (t != NULL && current != t)
+ rcu_wake_cond(t, __this_cpu_read(rcu_cpu_kthread_status));
+ local_irq_restore(flags);
+}
+
+static void rcu_cpu_kthread_park(unsigned int cpu)
+{
+ per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
+}
+
+static int rcu_cpu_kthread_should_run(unsigned int cpu)
+{
+ return __this_cpu_read(rcu_cpu_has_work);
+}
+
+/*
+ * Per-CPU kernel thread that invokes RCU callbacks. This replaces the
+ * RCU softirq used in flavors and configurations of RCU that do not
+ * support RCU priority boosting.
+ */
+static void rcu_cpu_kthread(unsigned int cpu)
+{
+ unsigned int *statusp = &__get_cpu_var(rcu_cpu_kthread_status);
+ char work, *workp = &__get_cpu_var(rcu_cpu_has_work);
+ int spincnt;
+
+ for (spincnt = 0; spincnt < 10; spincnt++) {
+ trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
+ local_bh_disable();
+ *statusp = RCU_KTHREAD_RUNNING;
+ this_cpu_inc(rcu_cpu_kthread_loops);
+ local_irq_disable();
+ work = *workp;
+ *workp = 0;
+ local_irq_enable();
+ if (work)
+ rcu_process_callbacks();
+ local_bh_enable();
+ if (*workp == 0) {
+ trace_rcu_utilization(TPS("End CPU kthread@rcu_wait"));
+ *statusp = RCU_KTHREAD_WAITING;
+ return;
+ }
}
- invoke_rcu_callbacks_kthread();
+ *statusp = RCU_KTHREAD_YIELDING;
+ trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
+ schedule_timeout_interruptible(2);
+ trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
+ *statusp = RCU_KTHREAD_WAITING;
}
-static void invoke_rcu_core(void)
+static struct smp_hotplug_thread rcu_cpu_thread_spec = {
+ .store = &rcu_cpu_kthread_task,
+ .thread_should_run = rcu_cpu_kthread_should_run,
+ .thread_fn = rcu_cpu_kthread,
+ .thread_comm = "rcuc/%u",
+ .setup = rcu_cpu_kthread_setup,
+ .park = rcu_cpu_kthread_park,
+};
+
+/*
+ * Spawn per-CPU RCU core processing kthreads.
+ */
+static int __init rcu_spawn_core_kthreads(void)
{
- if (cpu_online(smp_processor_id()))
- raise_softirq(RCU_SOFTIRQ);
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ per_cpu(rcu_cpu_has_work, cpu) = 0;
+ BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
+ return 0;
}
+early_initcall(rcu_spawn_core_kthreads);
/*
* Handle any core-RCU processing required by a call_rcu() invocation.
@@ -2373,6 +2476,7 @@ void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
}
EXPORT_SYMBOL_GPL(call_rcu_sched);
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Queue an RCU callback for invocation after a quicker grace period.
*/
@@ -2381,6 +2485,7 @@ void call_rcu_bh(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
__call_rcu(head, func, &rcu_bh_state, -1, 0);
}
EXPORT_SYMBOL_GPL(call_rcu_bh);
+#endif
/*
* Because a context switch is a grace period for RCU-sched and RCU-bh,
@@ -2458,6 +2563,7 @@ void synchronize_sched(void)
}
EXPORT_SYMBOL_GPL(synchronize_sched);
+#ifndef CONFIG_PREEMPT_RT_FULL
/**
* synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
*
@@ -2484,6 +2590,7 @@ void synchronize_rcu_bh(void)
wait_rcu_gp(call_rcu_bh);
}
EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
+#endif
static int synchronize_sched_expedited_cpu_stop(void *data)
{
@@ -2658,6 +2765,10 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
/* Check for CPU stalls, if enabled. */
check_cpu_stall(rsp, rdp);
+ /* Is this CPU a NO_HZ_FULL CPU that should ignore RCU? */
+ if (rcu_nohz_full_cpu(rsp))
+ return 0;
+
/* Is the RCU core waiting for a quiescent state from this CPU? */
if (rcu_scheduler_fully_active &&
rdp->qs_pending && !rdp->passed_quiesce) {
@@ -2891,6 +3002,7 @@ static void _rcu_barrier(struct rcu_state *rsp)
mutex_unlock(&rsp->barrier_mutex);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
/**
* rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
*/
@@ -2899,6 +3011,7 @@ void rcu_barrier_bh(void)
_rcu_barrier(&rcu_bh_state);
}
EXPORT_SYMBOL_GPL(rcu_barrier_bh);
+#endif
/**
* rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
@@ -3202,7 +3315,7 @@ static void __init rcu_init_one(struct rcu_state *rsp,
}
rsp->rda = rda;
- init_waitqueue_head(&rsp->gp_wq);
+ init_swait_head(&rsp->gp_wq);
init_irq_work(&rsp->wakeup_work, rsp_wakeup);
rnp = rsp->level[rcu_num_lvls - 1];
for_each_possible_cpu(i) {
@@ -3298,7 +3411,6 @@ void __init rcu_init(void)
rcu_init_one(&rcu_sched_state, &rcu_sched_data);
rcu_init_one(&rcu_bh_state, &rcu_bh_data);
__rcu_init_preempt();
- open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
/*
* We don't need protection against CPU-hotplug here because
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 52be957..1df8d9e 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -28,6 +28,7 @@
#include <linux/cpumask.h>
#include <linux/seqlock.h>
#include <linux/irq_work.h>
+#include <linux/wait-simple.h>
/*
* Define shape of hierarchy based on NR_CPUS, CONFIG_RCU_FANOUT, and
@@ -200,7 +201,7 @@ struct rcu_node {
/* This can happen due to race conditions. */
#endif /* #ifdef CONFIG_RCU_BOOST */
#ifdef CONFIG_RCU_NOCB_CPU
- wait_queue_head_t nocb_gp_wq[2];
+ struct swait_head nocb_gp_wq[2];
/* Place for rcu_nocb_kthread() to wait GP. */
#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
int need_future_gp[2];
@@ -333,7 +334,7 @@ struct rcu_data {
atomic_long_t nocb_q_count_lazy; /* (approximate). */
int nocb_p_count; /* # CBs being invoked by kthread */
int nocb_p_count_lazy; /* (approximate). */
- wait_queue_head_t nocb_wq; /* For nocb kthreads to sleep on. */
+ struct swait_head nocb_wq; /* For nocb kthreads to sleep on. */
struct task_struct *nocb_kthread;
#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
@@ -403,7 +404,7 @@ struct rcu_state {
unsigned long gpnum; /* Current gp number. */
unsigned long completed; /* # of last completed gp. */
struct task_struct *gp_kthread; /* Task for grace periods. */
- wait_queue_head_t gp_wq; /* Where GP task waits. */
+ struct swait_head gp_wq; /* Where GP task waits. */
int gp_flags; /* Commands for GP task. */
/* End of fields guarded by root rcu_node's lock. */
@@ -527,10 +528,9 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
static void __init __rcu_init_preempt(void);
static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
-static void invoke_rcu_callbacks_kthread(void);
static bool rcu_is_callbacks_kthread(void);
+static void rcu_cpu_kthread_setup(unsigned int cpu);
#ifdef CONFIG_RCU_BOOST
-static void rcu_preempt_do_callbacks(void);
static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
struct rcu_node *rnp);
#endif /* #ifdef CONFIG_RCU_BOOST */
@@ -564,6 +564,7 @@ static void rcu_sysidle_report_gp(struct rcu_state *rsp, int isidle,
unsigned long maxj);
static void rcu_bind_gp_kthread(void);
static void rcu_sysidle_init_percpu_data(struct rcu_dynticks *rdtp);
+static bool rcu_nohz_full_cpu(struct rcu_state *rsp);
#endif /* #ifndef RCU_TREE_NONCORE */
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 511e6b4..c849bd4 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -24,12 +24,6 @@
* Paul E. McKenney <paulmck@linux.vnet.ibm.com>
*/
-#include <linux/delay.h>
-#include <linux/gfp.h>
-#include <linux/oom.h>
-#include <linux/smpboot.h>
-#include "time/tick-internal.h"
-
#define RCU_KTHREAD_PRIO 1
#ifdef CONFIG_RCU_BOOST
@@ -359,7 +353,7 @@ void rcu_read_unlock_special(struct task_struct *t)
}
/* Hardware IRQ handlers cannot block. */
- if (in_irq() || in_serving_softirq()) {
+ if (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_OFFSET)) {
local_irq_restore(flags);
return;
}
@@ -656,15 +650,6 @@ static void rcu_preempt_check_callbacks(int cpu)
t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS;
}
-#ifdef CONFIG_RCU_BOOST
-
-static void rcu_preempt_do_callbacks(void)
-{
- rcu_do_batch(&rcu_preempt_state, &__get_cpu_var(rcu_preempt_data));
-}
-
-#endif /* #ifdef CONFIG_RCU_BOOST */
-
/*
* Queue a preemptible-RCU callback for invocation after a grace period.
*/
@@ -1126,6 +1111,19 @@ void exit_rcu(void)
#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
+/*
+ * If boosting, set rcuc kthreads to realtime priority.
+ */
+static void rcu_cpu_kthread_setup(unsigned int cpu)
+{
+#ifdef CONFIG_RCU_BOOST
+ struct sched_param sp;
+
+ sp.sched_priority = RCU_KTHREAD_PRIO;
+ sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
+#endif /* #ifdef CONFIG_RCU_BOOST */
+}
+
#ifdef CONFIG_RCU_BOOST
#include "rtmutex_common.h"
@@ -1157,16 +1155,6 @@ static void rcu_initiate_boost_trace(struct rcu_node *rnp)
#endif /* #else #ifdef CONFIG_RCU_TRACE */
-static void rcu_wake_cond(struct task_struct *t, int status)
-{
- /*
- * If the thread is yielding, only wake it when this
- * is invoked from idle
- */
- if (status != RCU_KTHREAD_YIELDING || is_idle_task(current))
- wake_up_process(t);
-}
-
/*
* Carry out RCU priority boosting on the task indicated by ->exp_tasks
* or ->boost_tasks, advancing the pointer to the next task in the
@@ -1310,23 +1298,6 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
}
/*
- * Wake up the per-CPU kthread to invoke RCU callbacks.
- */
-static void invoke_rcu_callbacks_kthread(void)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- __this_cpu_write(rcu_cpu_has_work, 1);
- if (__this_cpu_read(rcu_cpu_kthread_task) != NULL &&
- current != __this_cpu_read(rcu_cpu_kthread_task)) {
- rcu_wake_cond(__this_cpu_read(rcu_cpu_kthread_task),
- __this_cpu_read(rcu_cpu_kthread_status));
- }
- local_irq_restore(flags);
-}
-
-/*
* Is the current CPU running the RCU-callbacks kthread?
* Caller must have preemption disabled.
*/
@@ -1380,67 +1351,6 @@ static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
return 0;
}
-static void rcu_kthread_do_work(void)
-{
- rcu_do_batch(&rcu_sched_state, &__get_cpu_var(rcu_sched_data));
- rcu_do_batch(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
- rcu_preempt_do_callbacks();
-}
-
-static void rcu_cpu_kthread_setup(unsigned int cpu)
-{
- struct sched_param sp;
-
- sp.sched_priority = RCU_KTHREAD_PRIO;
- sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
-}
-
-static void rcu_cpu_kthread_park(unsigned int cpu)
-{
- per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
-}
-
-static int rcu_cpu_kthread_should_run(unsigned int cpu)
-{
- return __get_cpu_var(rcu_cpu_has_work);
-}
-
-/*
- * Per-CPU kernel thread that invokes RCU callbacks. This replaces the
- * RCU softirq used in flavors and configurations of RCU that do not
- * support RCU priority boosting.
- */
-static void rcu_cpu_kthread(unsigned int cpu)
-{
- unsigned int *statusp = &__get_cpu_var(rcu_cpu_kthread_status);
- char work, *workp = &__get_cpu_var(rcu_cpu_has_work);
- int spincnt;
-
- for (spincnt = 0; spincnt < 10; spincnt++) {
- trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
- local_bh_disable();
- *statusp = RCU_KTHREAD_RUNNING;
- this_cpu_inc(rcu_cpu_kthread_loops);
- local_irq_disable();
- work = *workp;
- *workp = 0;
- local_irq_enable();
- if (work)
- rcu_kthread_do_work();
- local_bh_enable();
- if (*workp == 0) {
- trace_rcu_utilization(TPS("End CPU kthread@rcu_wait"));
- *statusp = RCU_KTHREAD_WAITING;
- return;
- }
- }
- *statusp = RCU_KTHREAD_YIELDING;
- trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
- schedule_timeout_interruptible(2);
- trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
- *statusp = RCU_KTHREAD_WAITING;
-}
-
/*
* Set the per-rcu_node kthread's affinity to cover all CPUs that are
* served by the rcu_node in question. The CPU hotplug lock is still
@@ -1474,27 +1384,14 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
free_cpumask_var(cm);
}
-static struct smp_hotplug_thread rcu_cpu_thread_spec = {
- .store = &rcu_cpu_kthread_task,
- .thread_should_run = rcu_cpu_kthread_should_run,
- .thread_fn = rcu_cpu_kthread,
- .thread_comm = "rcuc/%u",
- .setup = rcu_cpu_kthread_setup,
- .park = rcu_cpu_kthread_park,
-};
-
/*
* Spawn all kthreads -- called as soon as the scheduler is running.
*/
static int __init rcu_spawn_kthreads(void)
{
struct rcu_node *rnp;
- int cpu;
rcu_scheduler_fully_active = 1;
- for_each_possible_cpu(cpu)
- per_cpu(rcu_cpu_has_work, cpu) = 0;
- BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
rnp = rcu_get_root(rcu_state);
(void)rcu_spawn_one_boost_kthread(rcu_state, rnp);
if (NUM_RCU_NODES > 1) {
@@ -1522,11 +1419,6 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
-static void invoke_rcu_callbacks_kthread(void)
-{
- WARN_ON_ONCE(1);
-}
-
static bool rcu_is_callbacks_kthread(void)
{
return false;
@@ -1553,7 +1445,7 @@ static void rcu_prepare_kthreads(int cpu)
#endif /* #else #ifdef CONFIG_RCU_BOOST */
-#if !defined(CONFIG_RCU_FAST_NO_HZ)
+#if !defined(CONFIG_RCU_FAST_NO_HZ) || defined(CONFIG_PREEMPT_RT_FULL)
/*
* Check to see if any future RCU-related work will need to be done
@@ -1569,6 +1461,9 @@ int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
*delta_jiffies = ULONG_MAX;
return rcu_cpu_has_callbacks(cpu, NULL);
}
+#endif /* !defined(CONFIG_RCU_FAST_NO_HZ) || defined(CONFIG_PREEMPT_RT_FULL) */
+
+#if !defined(CONFIG_RCU_FAST_NO_HZ)
/*
* Because we do not have RCU_FAST_NO_HZ, don't bother cleaning up
@@ -1666,6 +1561,8 @@ static bool rcu_try_advance_all_cbs(void)
return cbs_ready;
}
+#ifndef CONFIG_PREEMPT_RT_FULL
+
/*
* Allow the CPU to enter dyntick-idle mode unless it has callbacks ready
* to invoke. If the CPU has callbacks, try to advance them. Tell the
@@ -1704,6 +1601,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj)
}
return 0;
}
+#endif /* #ifndef CONFIG_PREEMPT_RT_FULL */
/*
* Prepare a CPU for idle from an RCU perspective. The first major task
@@ -2061,7 +1959,7 @@ static int rcu_nocb_needs_gp(struct rcu_state *rsp)
*/
static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
{
- wake_up_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
+ swait_wake_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
}
/*
@@ -2079,8 +1977,8 @@ static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq)
static void rcu_init_one_nocb(struct rcu_node *rnp)
{
- init_waitqueue_head(&rnp->nocb_gp_wq[0]);
- init_waitqueue_head(&rnp->nocb_gp_wq[1]);
+ init_swait_head(&rnp->nocb_gp_wq[0]);
+ init_swait_head(&rnp->nocb_gp_wq[1]);
}
/* Is the specified CPU a no-CPUs CPU? */
@@ -2120,7 +2018,7 @@ static void __call_rcu_nocb_enqueue(struct rcu_data *rdp,
return;
len = atomic_long_read(&rdp->nocb_q_count);
if (old_rhpp == &rdp->nocb_head) {
- wake_up(&rdp->nocb_wq); /* ... only if queue was empty ... */
+ swait_wake(&rdp->nocb_wq); /* ... only if queue was empty ... */
rdp->qlen_last_fqs_check = 0;
} else if (len > rdp->qlen_last_fqs_check + qhimark) {
wake_up_process(t); /* ... or if many callbacks queued. */
@@ -2210,7 +2108,7 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
*/
trace_rcu_future_gp(rnp, rdp, c, TPS("StartWait"));
for (;;) {
- wait_event_interruptible(
+ swait_event_interruptible(
rnp->nocb_gp_wq[c & 0x1],
(d = ULONG_CMP_GE(ACCESS_ONCE(rnp->completed), c)));
if (likely(d))
@@ -2238,7 +2136,7 @@ static int rcu_nocb_kthread(void *arg)
for (;;) {
/* If not polling, wait for next batch of callbacks. */
if (!rcu_nocb_poll)
- wait_event_interruptible(rdp->nocb_wq, rdp->nocb_head);
+ swait_event_interruptible(rdp->nocb_wq, rdp->nocb_head);
list = ACCESS_ONCE(rdp->nocb_head);
if (!list) {
schedule_timeout_interruptible(1);
@@ -2288,7 +2186,7 @@ static int rcu_nocb_kthread(void *arg)
static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
{
rdp->nocb_tail = &rdp->nocb_head;
- init_waitqueue_head(&rdp->nocb_wq);
+ init_swait_head(&rdp->nocb_wq);
}
/* Create a kthread for each RCU flavor for each no-CBs CPU. */
@@ -2803,3 +2701,23 @@ static void rcu_sysidle_init_percpu_data(struct rcu_dynticks *rdtp)
}
#endif /* #else #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */
+
+/*
+ * Is this CPU a NO_HZ_FULL CPU that should ignore RCU so that the
+ * grace-period kthread will do force_quiescent_state() processing?
+ * The idea is to avoid waking up RCU core processing on such a
+ * CPU unless the grace period has extended for too long.
+ *
+ * This code relies on the fact that all NO_HZ_FULL CPUs are also
+ * CONFIG_RCU_NOCB_CPUs.
+ */
+static bool rcu_nohz_full_cpu(struct rcu_state *rsp)
+{
+#ifdef CONFIG_NO_HZ_FULL
+ if (tick_nohz_full_cpu(smp_processor_id()) &&
+ (!rcu_gp_in_progress(rsp) ||
+ ULONG_CMP_LT(jiffies, ACCESS_ONCE(rsp->gp_start) + HZ)))
+ return 1;
+#endif /* #ifdef CONFIG_NO_HZ_FULL */
+ return 0;
+}
diff --git a/kernel/relay.c b/kernel/relay.c
index 5001c98..b915513 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -339,6 +339,10 @@ static void wakeup_readers(unsigned long data)
{
struct rchan_buf *buf = (struct rchan_buf *)data;
wake_up_interruptible(&buf->read_wait);
+ /*
+ * Stupid polling for now:
+ */
+ mod_timer(&buf->timer, jiffies + 1);
}
/**
@@ -356,6 +360,7 @@ static void __relay_reset(struct rchan_buf *buf, unsigned int init)
init_waitqueue_head(&buf->read_wait);
kref_init(&buf->kref);
setup_timer(&buf->timer, wakeup_readers, (unsigned long)buf);
+ mod_timer(&buf->timer, jiffies + 1);
} else
del_timer_sync(&buf->timer);
@@ -739,15 +744,6 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
else
buf->early_bytes += buf->chan->subbuf_size -
buf->padding[old_subbuf];
- smp_mb();
- if (waitqueue_active(&buf->read_wait))
- /*
- * Calling wake_up_interruptible() from here
- * will deadlock if we happen to be logging
- * from the scheduler (trying to re-grab
- * rq->lock), so defer it.
- */
- mod_timer(&buf->timer, jiffies + 1);
}
old = buf->data;
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index 4aa8a30..3fbcb0d 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -49,7 +49,7 @@ static int __res_counter_charge(struct res_counter *counter, unsigned long val,
r = ret = 0;
*limit_fail_at = NULL;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
for (c = counter; c != NULL; c = c->parent) {
spin_lock(&c->lock);
r = res_counter_charge_locked(c, val, force);
@@ -69,7 +69,7 @@ static int __res_counter_charge(struct res_counter *counter, unsigned long val,
spin_unlock(&u->lock);
}
}
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return ret;
}
@@ -103,7 +103,7 @@ u64 res_counter_uncharge_until(struct res_counter *counter,
struct res_counter *c;
u64 ret = 0;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
for (c = counter; c != top; c = c->parent) {
u64 r;
spin_lock(&c->lock);
@@ -112,7 +112,7 @@ u64 res_counter_uncharge_until(struct res_counter *counter,
ret = r;
spin_unlock(&c->lock);
}
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return ret;
}
diff --git a/kernel/rt.c b/kernel/rt.c
new file mode 100644
index 0000000..5d17727
--- /dev/null
+++ b/kernel/rt.c
@@ -0,0 +1,452 @@
+/*
+ * kernel/rt.c
+ *
+ * Real-Time Preemption Support
+ *
+ * started by Ingo Molnar:
+ *
+ * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * historic credit for proving that Linux spinlocks can be implemented via
+ * RT-aware mutexes goes to many people: The Pmutex project (Dirk Grambow
+ * and others) who prototyped it on 2.4 and did lots of comparative
+ * research and analysis; TimeSys, for proving that you can implement a
+ * fully preemptible kernel via the use of IRQ threading and mutexes;
+ * Bill Huey for persuasively arguing on lkml that the mutex model is the
+ * right one; and to MontaVista, who ported pmutexes to 2.6.
+ *
+ * This code is a from-scratch implementation and is not based on pmutexes,
+ * but the idea of converting spinlocks to mutexes is used here too.
+ *
+ * lock debugging, locking tree, deadlock detection:
+ *
+ * Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
+ * Released under the General Public License (GPL).
+ *
+ * Includes portions of the generic R/W semaphore implementation from:
+ *
+ * Copyright (c) 2001 David Howells (dhowells@redhat.com).
+ * - Derived partially from idea by Andrea Arcangeli <andrea@suse.de>
+ * - Derived also from comments by Linus
+ *
+ * Pending ownership of locks and ownership stealing:
+ *
+ * Copyright (C) 2005, Kihon Technologies Inc., Steven Rostedt
+ *
+ * (also by Steven Rostedt)
+ * - Converted single pi_lock to individual task locks.
+ *
+ * By Esben Nielsen:
+ * Doing priority inheritance with help of the scheduler.
+ *
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ * - major rework based on Esben Nielsens initial patch
+ * - replaced thread_info references by task_struct refs
+ * - removed task->pending_owner dependency
+ * - BKL drop/reacquire for semaphore style locks to avoid deadlocks
+ * in the scheduler return path as discussed with Steven Rostedt
+ *
+ * Copyright (C) 2006, Kihon Technologies Inc.
+ * Steven Rostedt <rostedt@goodmis.org>
+ * - debugged and patched Thomas Gleixner's rework.
+ * - added back the cmpxchg to the rework.
+ * - turned atomic require back on for SMP.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/rtmutex.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/syscalls.h>
+#include <linux/interrupt.h>
+#include <linux/plist.h>
+#include <linux/fs.h>
+#include <linux/futex.h>
+#include <linux/hrtimer.h>
+
+#include "rtmutex_common.h"
+
+/*
+ * struct mutex functions
+ */
+void __mutex_do_init(struct mutex *mutex, const char *name,
+ struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)mutex, sizeof(*mutex));
+ lockdep_init_map(&mutex->dep_map, name, key, 0);
+#endif
+ mutex->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__mutex_do_init);
+
+void __lockfunc _mutex_lock(struct mutex *lock)
+{
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock);
+
+int __lockfunc _mutex_lock_interruptible(struct mutex *lock)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_lock_interruptible(&lock->lock, 0);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible);
+
+int __lockfunc _mutex_lock_killable(struct mutex *lock)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_lock_killable(&lock->lock, 0);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass)
+{
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+ rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock_nested);
+
+void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
+{
+ mutex_acquire_nest(&lock->dep_map, 0, 0, nest, _RET_IP_);
+ rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock_nest_lock);
+
+int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass)
+{
+ int ret;
+
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+ ret = rt_mutex_lock_interruptible(&lock->lock, 0);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible_nested);
+
+int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+ ret = rt_mutex_lock_killable(&lock->lock, 0);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable_nested);
+#endif
+
+int __lockfunc _mutex_trylock(struct mutex *lock)
+{
+ int ret = rt_mutex_trylock(&lock->lock);
+
+ if (ret)
+ mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_trylock);
+
+void __lockfunc _mutex_unlock(struct mutex *lock)
+{
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ rt_mutex_unlock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_unlock);
+
+/*
+ * rwlock_t functions
+ */
+int __lockfunc rt_write_trylock(rwlock_t *rwlock)
+{
+ int ret = rt_mutex_trylock(&rwlock->lock);
+
+ if (ret) {
+ rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+ migrate_disable();
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(rt_write_trylock);
+
+int __lockfunc rt_write_trylock_irqsave(rwlock_t *rwlock, unsigned long *flags)
+{
+ int ret;
+
+ *flags = 0;
+ ret = rt_write_trylock(rwlock);
+ return ret;
+}
+EXPORT_SYMBOL(rt_write_trylock_irqsave);
+
+int __lockfunc rt_read_trylock(rwlock_t *rwlock)
+{
+ struct rt_mutex *lock = &rwlock->lock;
+ int ret = 1;
+
+ /*
+ * recursive read locks succeed when current owns the lock,
+ * but not when read_depth == 0 which means that the lock is
+ * write locked.
+ */
+ if (rt_mutex_owner(lock) != current) {
+ ret = rt_mutex_trylock(lock);
+ if (ret) {
+ rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+ migrate_disable();
+ }
+ } else if (!rwlock->read_depth) {
+ ret = 0;
+ }
+
+ if (ret)
+ rwlock->read_depth++;
+
+ return ret;
+}
+EXPORT_SYMBOL(rt_read_trylock);
+
+void __lockfunc rt_write_lock(rwlock_t *rwlock)
+{
+ rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
+ migrate_disable();
+ __rt_spin_lock(&rwlock->lock);
+}
+EXPORT_SYMBOL(rt_write_lock);
+
+void __lockfunc rt_read_lock(rwlock_t *rwlock)
+{
+ struct rt_mutex *lock = &rwlock->lock;
+
+ /*
+ * recursive read locks succeed when current owns the lock
+ */
+ if (rt_mutex_owner(lock) != current) {
+ rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
+ __rt_spin_lock(lock);
+ migrate_disable();
+ }
+ rwlock->read_depth++;
+}
+
+EXPORT_SYMBOL(rt_read_lock);
+
+void __lockfunc rt_write_unlock(rwlock_t *rwlock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+ __rt_spin_unlock(&rwlock->lock);
+ migrate_enable();
+}
+EXPORT_SYMBOL(rt_write_unlock);
+
+void __lockfunc rt_read_unlock(rwlock_t *rwlock)
+{
+ /* Release the lock only when read_depth is down to 0 */
+ if (--rwlock->read_depth == 0) {
+ rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+ __rt_spin_unlock(&rwlock->lock);
+ migrate_enable();
+ }
+}
+EXPORT_SYMBOL(rt_read_unlock);
+
+unsigned long __lockfunc rt_write_lock_irqsave(rwlock_t *rwlock)
+{
+ rt_write_lock(rwlock);
+
+ return 0;
+}
+EXPORT_SYMBOL(rt_write_lock_irqsave);
+
+unsigned long __lockfunc rt_read_lock_irqsave(rwlock_t *rwlock)
+{
+ rt_read_lock(rwlock);
+
+ return 0;
+}
+EXPORT_SYMBOL(rt_read_lock_irqsave);
+
+void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)rwlock, sizeof(*rwlock));
+ lockdep_init_map(&rwlock->dep_map, name, key, 0);
+#endif
+ rwlock->lock.save_state = 1;
+ rwlock->read_depth = 0;
+}
+EXPORT_SYMBOL(__rt_rwlock_init);
+
+/*
+ * rw_semaphores
+ */
+
+void rt_up_write(struct rw_semaphore *rwsem)
+{
+ rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+ rt_mutex_unlock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_up_write);
+
+void rt_up_read(struct rw_semaphore *rwsem)
+{
+ if (--rwsem->read_depth == 0) {
+ rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+ rt_mutex_unlock(&rwsem->lock);
+ }
+}
+EXPORT_SYMBOL(rt_up_read);
+
+/*
+ * downgrade a write lock into a read lock
+ * - just wake up any readers at the front of the queue
+ */
+void rt_downgrade_write(struct rw_semaphore *rwsem)
+{
+ BUG_ON(rt_mutex_owner(&rwsem->lock) != current);
+ rwsem->read_depth = 1;
+}
+EXPORT_SYMBOL(rt_downgrade_write);
+
+int rt_down_write_trylock(struct rw_semaphore *rwsem)
+{
+ int ret = rt_mutex_trylock(&rwsem->lock);
+
+ if (ret)
+ rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(rt_down_write_trylock);
+
+void rt_down_write(struct rw_semaphore *rwsem)
+{
+ rwsem_acquire(&rwsem->dep_map, 0, 0, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write);
+
+void rt_down_write_nested(struct rw_semaphore *rwsem, int subclass)
+{
+ rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write_nested);
+
+void rt_down_write_nested_lock(struct rw_semaphore *rwsem,
+ struct lockdep_map *nest)
+{
+ rwsem_acquire_nest(&rwsem->dep_map, 0, 0, nest, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+}
+
+int rt_down_read_trylock(struct rw_semaphore *rwsem)
+{
+ struct rt_mutex *lock = &rwsem->lock;
+ int ret = 1;
+
+ /*
+ * recursive read locks succeed when current owns the rwsem,
+ * but not when read_depth == 0 which means that the rwsem is
+ * write locked.
+ */
+ if (rt_mutex_owner(lock) != current) {
+ ret = rt_mutex_trylock(&rwsem->lock);
+ if (ret)
+ rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
+ } else if (!rwsem->read_depth) {
+ ret = 0;
+ }
+
+ if (ret)
+ rwsem->read_depth++;
+ return ret;
+}
+EXPORT_SYMBOL(rt_down_read_trylock);
+
+static void __rt_down_read(struct rw_semaphore *rwsem, int subclass)
+{
+ struct rt_mutex *lock = &rwsem->lock;
+
+ if (rt_mutex_owner(lock) != current) {
+ rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+ }
+ rwsem->read_depth++;
+}
+
+void rt_down_read(struct rw_semaphore *rwsem)
+{
+ __rt_down_read(rwsem, 0);
+}
+EXPORT_SYMBOL(rt_down_read);
+
+void rt_down_read_nested(struct rw_semaphore *rwsem, int subclass)
+{
+ __rt_down_read(rwsem, subclass);
+}
+EXPORT_SYMBOL(rt_down_read_nested);
+
+void __rt_rwsem_init(struct rw_semaphore *rwsem, const char *name,
+ struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)rwsem, sizeof(*rwsem));
+ lockdep_init_map(&rwsem->dep_map, name, key, 0);
+#endif
+ rwsem->read_depth = 0;
+ rwsem->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__rt_rwsem_init);
+
+/**
+ * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
+ * @cnt: the atomic which we are to dec
+ * @lock: the mutex to return holding if we dec to 0
+ *
+ * return true and hold lock if we dec to 0, return false otherwise
+ */
+int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
+{
+ /* dec if we can't possibly hit 0 */
+ if (atomic_add_unless(cnt, -1, 1))
+ return 0;
+ /* we might hit 0, so take the lock */
+ mutex_lock(lock);
+ if (!atomic_dec_and_test(cnt)) {
+ /* when we actually did the dec, we didn't hit 0 */
+ mutex_unlock(lock);
+ return 0;
+ }
+ /* we hit 0, and we hold the lock */
+ return 1;
+}
+EXPORT_SYMBOL(atomic_dec_and_mutex_lock);
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 0dd6aec..4057bc6 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -8,6 +8,12 @@
* Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt
* Copyright (C) 2006 Esben Nielsen
*
+ * Adaptive Spinlocks:
+ * Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich,
+ * and Peter Morreale,
+ * Adaptive Spinlocks simplification:
+ * Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com>
+ *
* See Documentation/rt-mutex-design.txt for details.
*/
#include <linux/spinlock.h>
@@ -15,6 +21,7 @@
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/timer.h>
+#include <linux/ww_mutex.h>
#include "rtmutex_common.h"
@@ -68,6 +75,12 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock)
clear_rt_mutex_waiters(lock);
}
+static int rt_mutex_real_waiter(struct rt_mutex_waiter *waiter)
+{
+ return waiter && waiter != PI_WAKEUP_INPROGRESS &&
+ waiter != PI_REQUEUE_INPROGRESS;
+}
+
/*
* We can speed up the acquire/release, if the architecture
* supports cmpxchg and if there's no debugging state to be set up
@@ -91,6 +104,12 @@ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
}
#endif
+static inline void init_lists(struct rt_mutex *lock)
+{
+ if (unlikely(!lock->wait_list.node_list.prev))
+ plist_head_init(&lock->wait_list);
+}
+
/*
* Calculate task priority from the waiter list priority
*
@@ -107,6 +126,18 @@ int rt_mutex_getprio(struct task_struct *task)
}
/*
+ * Called by sched_setscheduler() to check whether the priority change
+ * is overruled by a possible priority boosting.
+ */
+int rt_mutex_check_prio(struct task_struct *task, int newprio)
+{
+ if (!task_has_pi_waiters(task))
+ return 0;
+
+ return task_top_pi_waiter(task)->pi_list_entry.prio <= newprio;
+}
+
+/*
* Adjust the priority of a task, after its pi_waiters got modified.
*
* This can be both boosting and unboosting. task->pi_lock must be held.
@@ -137,6 +168,14 @@ static void rt_mutex_adjust_prio(struct task_struct *task)
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
}
+static void rt_mutex_wake_waiter(struct rt_mutex_waiter *waiter)
+{
+ if (waiter->savestate)
+ wake_up_lock_sleeper(waiter->task);
+ else
+ wake_up_process(waiter->task);
+}
+
/*
* Max number of times we'll walk the boosting chain:
*/
@@ -210,7 +249,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
* reached or the state of the chain has changed while we
* dropped the locks.
*/
- if (!waiter)
+ if (!rt_mutex_real_waiter(waiter))
goto out_unlock_pi;
/*
@@ -261,13 +300,15 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
/* Release the task */
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
if (!rt_mutex_owner(lock)) {
+ struct rt_mutex_waiter *lock_top_waiter;
+
/*
* If the requeue above changed the top waiter, then we need
* to wake the new top waiter up to try to get the lock.
*/
-
- if (top_waiter != rt_mutex_top_waiter(lock))
- wake_up_process(rt_mutex_top_waiter(lock)->task);
+ lock_top_waiter = rt_mutex_top_waiter(lock);
+ if (top_waiter != lock_top_waiter)
+ rt_mutex_wake_waiter(lock_top_waiter);
raw_spin_unlock(&lock->wait_lock);
goto out_put_task;
}
@@ -312,6 +353,25 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
return ret;
}
+
+#define STEAL_NORMAL 0
+#define STEAL_LATERAL 1
+
+/*
+ * Note that RT tasks are excluded from lateral-steals to prevent the
+ * introduction of an unbounded latency
+ */
+static inline int lock_is_stealable(struct task_struct *task,
+ struct task_struct *pendowner, int mode)
+{
+ if (mode == STEAL_NORMAL || rt_task(task)) {
+ if (task->prio >= pendowner->prio)
+ return 0;
+ } else if (task->prio > pendowner->prio)
+ return 0;
+ return 1;
+}
+
/*
* Try to take an rt-mutex
*
@@ -321,8 +381,9 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
* @task: the task which wants to acquire the lock
* @waiter: the waiter that is queued to the lock's wait list. (could be NULL)
*/
-static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
- struct rt_mutex_waiter *waiter)
+static int
+__try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+ struct rt_mutex_waiter *waiter, int mode)
{
/*
* We have to be careful here if the atomic speedups are
@@ -355,12 +416,14 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
* 3) it is top waiter
*/
if (rt_mutex_has_waiters(lock)) {
- if (task->prio >= rt_mutex_top_waiter(lock)->list_entry.prio) {
- if (!waiter || waiter != rt_mutex_top_waiter(lock))
- return 0;
- }
+ struct task_struct *pown = rt_mutex_top_waiter(lock)->task;
+
+ if (task != pown && !lock_is_stealable(task, pown, mode))
+ return 0;
}
+ /* We got the lock. */
+
if (waiter || rt_mutex_has_waiters(lock)) {
unsigned long flags;
struct rt_mutex_waiter *top;
@@ -385,7 +448,6 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
}
- /* We got the lock. */
debug_rt_mutex_lock(lock);
rt_mutex_set_owner(lock, task);
@@ -395,6 +457,13 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
return 1;
}
+static inline int
+try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+ struct rt_mutex_waiter *waiter)
+{
+ return __try_to_take_rt_mutex(lock, task, waiter, STEAL_NORMAL);
+}
+
/*
* Task blocks on lock.
*
@@ -413,6 +482,23 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
int chain_walk = 0, res;
raw_spin_lock_irqsave(&task->pi_lock, flags);
+
+ /*
+ * In the case of futex requeue PI, this will be a proxy
+ * lock. The task will wake unaware that it is enqueueed on
+ * this lock. Avoid blocking on two locks and corrupting
+ * pi_blocked_on via the PI_WAKEUP_INPROGRESS
+ * flag. futex_wait_requeue_pi() sets this when it wakes up
+ * before requeue (due to a signal or timeout). Do not enqueue
+ * the task if PI_WAKEUP_INPROGRESS is set.
+ */
+ if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) {
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ return -EAGAIN;
+ }
+
+ BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on));
+
__rt_mutex_adjust_prio(task);
waiter->task = task;
waiter->lock = lock;
@@ -437,7 +523,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
plist_add(&waiter->pi_list_entry, &owner->pi_waiters);
__rt_mutex_adjust_prio(owner);
- if (owner->pi_blocked_on)
+ if (rt_mutex_real_waiter(owner->pi_blocked_on))
chain_walk = 1;
raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
}
@@ -492,7 +578,7 @@ static void wakeup_next_waiter(struct rt_mutex *lock)
raw_spin_unlock_irqrestore(&current->pi_lock, flags);
- wake_up_process(waiter->task);
+ rt_mutex_wake_waiter(waiter);
}
/*
@@ -531,7 +617,7 @@ static void remove_waiter(struct rt_mutex *lock,
}
__rt_mutex_adjust_prio(owner);
- if (owner->pi_blocked_on)
+ if (rt_mutex_real_waiter(owner->pi_blocked_on))
chain_walk = 1;
raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
@@ -565,23 +651,371 @@ void rt_mutex_adjust_pi(struct task_struct *task)
raw_spin_lock_irqsave(&task->pi_lock, flags);
waiter = task->pi_blocked_on;
- if (!waiter || waiter->list_entry.prio == task->prio) {
+ if (!rt_mutex_real_waiter(waiter) ||
+ waiter->list_entry.prio == task->prio) {
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
return;
}
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
-
/* gets dropped in rt_mutex_adjust_prio_chain()! */
get_task_struct(task);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * preemptible spin_lock functions:
+ */
+static inline void rt_spin_lock_fastlock(struct rt_mutex *lock,
+ void (*slowfn)(struct rt_mutex *lock))
+{
+ might_sleep();
+
+ if (likely(rt_mutex_cmpxchg(lock, NULL, current)))
+ rt_mutex_deadlock_account_lock(lock, current);
+ else
+ slowfn(lock);
+}
+
+static inline void rt_spin_lock_fastunlock(struct rt_mutex *lock,
+ void (*slowfn)(struct rt_mutex *lock))
+{
+ if (likely(rt_mutex_cmpxchg(lock, current, NULL)))
+ rt_mutex_deadlock_account_unlock(current);
+ else
+ slowfn(lock);
+}
+
+#ifdef CONFIG_SMP
+/*
+ * Note that owner is a speculative pointer and dereferencing relies
+ * on rcu_read_lock() and the check against the lock owner.
+ */
+static int adaptive_wait(struct rt_mutex *lock,
+ struct task_struct *owner)
+{
+ int res = 0;
+
+ rcu_read_lock();
+ for (;;) {
+ if (owner != rt_mutex_owner(lock))
+ break;
+ /*
+ * Ensure that owner->on_cpu is dereferenced _after_
+ * checking the above to be valid.
+ */
+ barrier();
+ if (!owner->on_cpu) {
+ res = 1;
+ break;
+ }
+ cpu_relax();
+ }
+ rcu_read_unlock();
+ return res;
+}
+#else
+static int adaptive_wait(struct rt_mutex *lock,
+ struct task_struct *orig_owner)
+{
+ return 1;
+}
+#endif
+
+# define pi_lock(lock) raw_spin_lock_irq(lock)
+# define pi_unlock(lock) raw_spin_unlock_irq(lock)
+
+/*
+ * Slow path lock function spin_lock style: this variant is very
+ * careful not to miss any non-lock wakeups.
+ *
+ * We store the current state under p->pi_lock in p->saved_state and
+ * the try_to_wake_up() code handles this accordingly.
+ */
+static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
+{
+ struct task_struct *lock_owner, *self = current;
+ struct rt_mutex_waiter waiter, *top_waiter;
+ int ret;
+
+ rt_mutex_init_waiter(&waiter, true);
+
+ raw_spin_lock(&lock->wait_lock);
+ init_lists(lock);
+
+ if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL)) {
+ raw_spin_unlock(&lock->wait_lock);
+ return;
+ }
+
+ BUG_ON(rt_mutex_owner(lock) == self);
+
+ /*
+ * We save whatever state the task is in and we'll restore it
+ * after acquiring the lock taking real wakeups into account
+ * as well. We are serialized via pi_lock against wakeups. See
+ * try_to_wake_up().
+ */
+ pi_lock(&self->pi_lock);
+ self->saved_state = self->state;
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ pi_unlock(&self->pi_lock);
+
+ ret = task_blocks_on_rt_mutex(lock, &waiter, self, 0);
+ BUG_ON(ret);
+
+ for (;;) {
+ /* Try to acquire the lock again. */
+ if (__try_to_take_rt_mutex(lock, self, &waiter, STEAL_LATERAL))
+ break;
+
+ top_waiter = rt_mutex_top_waiter(lock);
+ lock_owner = rt_mutex_owner(lock);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ debug_rt_mutex_print_deadlock(&waiter);
+
+ if (top_waiter != &waiter || adaptive_wait(lock, lock_owner))
+ schedule_rt_mutex(lock);
+
+ raw_spin_lock(&lock->wait_lock);
+
+ pi_lock(&self->pi_lock);
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ pi_unlock(&self->pi_lock);
+ }
+
+ /*
+ * Restore the task state to current->saved_state. We set it
+ * to the original state above and the try_to_wake_up() code
+ * has possibly updated it when a real (non-rtmutex) wakeup
+ * happened while we were blocked. Clear saved_state so
+ * try_to_wakeup() does not get confused.
+ */
+ pi_lock(&self->pi_lock);
+ __set_current_state(self->saved_state);
+ self->saved_state = TASK_RUNNING;
+ pi_unlock(&self->pi_lock);
+
+ /*
+ * try_to_take_rt_mutex() sets the waiter bit
+ * unconditionally. We might have to fix that up:
+ */
+ fixup_rt_mutex_waiters(lock);
+
+ BUG_ON(rt_mutex_has_waiters(lock) && &waiter == rt_mutex_top_waiter(lock));
+ BUG_ON(!plist_node_empty(&waiter.list_entry));
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ debug_rt_mutex_free_waiter(&waiter);
+}
+
+/*
+ * Slow path to release a rt_mutex spin_lock style
+ */
+static void __sched __rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+ debug_rt_mutex_unlock(lock);
+
+ rt_mutex_deadlock_account_unlock(current);
+
+ if (!rt_mutex_has_waiters(lock)) {
+ lock->owner = NULL;
+ raw_spin_unlock(&lock->wait_lock);
+ return;
+ }
+
+ wakeup_next_waiter(lock);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ /* Undo pi boosting.when necessary */
+ rt_mutex_adjust_prio(current);
+}
+
+static void noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+ raw_spin_lock(&lock->wait_lock);
+ __rt_spin_lock_slowunlock(lock);
+}
+
+static void noinline __sched rt_spin_lock_slowunlock_hirq(struct rt_mutex *lock)
+{
+ int ret;
+
+ do {
+ ret = raw_spin_trylock(&lock->wait_lock);
+ } while (!ret);
+
+ __rt_spin_lock_slowunlock(lock);
+}
+
+void __lockfunc rt_spin_lock(spinlock_t *lock)
+{
+ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+ spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(rt_spin_lock);
+
+void __lockfunc __rt_spin_lock(struct rt_mutex *lock)
+{
+ rt_spin_lock_fastlock(lock, rt_spin_lock_slowlock);
+}
+EXPORT_SYMBOL(__rt_spin_lock);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass)
+{
+ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+ spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(rt_spin_lock_nested);
+#endif
+
+void __lockfunc rt_spin_unlock(spinlock_t *lock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(rt_spin_unlock);
+
+void __lockfunc rt_spin_unlock_after_trylock_in_irq(spinlock_t *lock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock_hirq);
+}
+
+void __lockfunc __rt_spin_unlock(struct rt_mutex *lock)
+{
+ rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(__rt_spin_unlock);
+
+/*
+ * Wait for the lock to get unlocked: instead of polling for an unlock
+ * (like raw spinlocks do), we lock and unlock, to force the kernel to
+ * schedule if there's contention:
+ */
+void __lockfunc rt_spin_unlock_wait(spinlock_t *lock)
+{
+ spin_lock(lock);
+ spin_unlock(lock);
+}
+EXPORT_SYMBOL(rt_spin_unlock_wait);
+
+int __lockfunc rt_spin_trylock(spinlock_t *lock)
+{
+ int ret = rt_mutex_trylock(&lock->lock);
+
+ if (ret)
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock);
+
+int __lockfunc rt_spin_trylock_bh(spinlock_t *lock)
+{
+ int ret;
+
+ local_bh_disable();
+ ret = rt_mutex_trylock(&lock->lock);
+ if (ret) {
+ migrate_disable();
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ } else
+ local_bh_enable();
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_bh);
+
+int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags)
+{
+ int ret;
+
+ *flags = 0;
+ ret = rt_mutex_trylock(&lock->lock);
+ if (ret) {
+ migrate_disable();
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_irqsave);
+
+int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock)
+{
+ /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
+ if (atomic_add_unless(atomic, -1, 1))
+ return 0;
+ rt_spin_lock(lock);
+ if (atomic_dec_and_test(atomic)){
+ migrate_disable();
+ return 1;
+ }
+ rt_spin_unlock(lock);
+ return 0;
+}
+EXPORT_SYMBOL(atomic_dec_and_spin_lock);
+
+void
+__rt_spin_lock_init(spinlock_t *lock, char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+ lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
+}
+EXPORT_SYMBOL(__rt_spin_lock_init);
+
+#endif /* PREEMPT_RT_FULL */
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+ struct ww_acquire_ctx *hold_ctx = ACCESS_ONCE(ww->ctx);
+
+ if (!hold_ctx)
+ return 0;
+
+ if (unlikely(ctx == hold_ctx))
+ return -EALREADY;
+
+ if (ctx->stamp - hold_ctx->stamp <= LONG_MAX &&
+ (ctx->stamp != hold_ctx->stamp || ctx > hold_ctx)) {
+#ifdef CONFIG_DEBUG_MUTEXES
+ DEBUG_LOCKS_WARN_ON(ctx->contending_lock);
+ ctx->contending_lock = ww;
+#endif
+ return -EDEADLK;
+ }
+
+ return 0;
+}
+#else
+static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ BUG();
+ return 0;
+}
+
+#endif
+
/**
* __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
* @lock: the rt_mutex to take
* @state: the state the task should block in (TASK_INTERRUPTIBLE
- * or TASK_UNINTERRUPTIBLE)
+ * or TASK_UNINTERRUPTIBLE)
* @timeout: the pre-initialized and started timer, or NULL for none
* @waiter: the pre-initialized rt_mutex_waiter
*
@@ -590,7 +1024,8 @@ void rt_mutex_adjust_pi(struct task_struct *task)
static int __sched
__rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- struct rt_mutex_waiter *waiter)
+ struct rt_mutex_waiter *waiter,
+ struct ww_acquire_ctx *ww_ctx)
{
int ret = 0;
@@ -613,6 +1048,12 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
break;
}
+ if (ww_ctx && ww_ctx->acquired > 0) {
+ ret = __mutex_lock_check_stamp(lock, ww_ctx);
+ if (ret)
+ break;
+ }
+
raw_spin_unlock(&lock->wait_lock);
debug_rt_mutex_print_deadlock(waiter);
@@ -626,23 +1067,102 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
return ret;
}
+static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww,
+ struct ww_acquire_ctx *ww_ctx)
+{
+#ifdef CONFIG_DEBUG_MUTEXES
+ /*
+ * If this WARN_ON triggers, you used ww_mutex_lock to acquire,
+ * but released with a normal mutex_unlock in this call.
+ *
+ * This should never happen, always use ww_mutex_unlock.
+ */
+ DEBUG_LOCKS_WARN_ON(ww->ctx);
+
+ /*
+ * Not quite done after calling ww_acquire_done() ?
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire);
+
+ if (ww_ctx->contending_lock) {
+ /*
+ * After -EDEADLK you tried to
+ * acquire a different ww_mutex? Bad!
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww);
+
+ /*
+ * You called ww_mutex_lock after receiving -EDEADLK,
+ * but 'forgot' to unlock everything else first?
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0);
+ ww_ctx->contending_lock = NULL;
+ }
+
+ /*
+ * Naughty, using a different class will lead to undefined behavior!
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class);
+#endif
+ ww_ctx->acquired++;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+ struct ww_acquire_ctx *ww_ctx)
+{
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+ struct rt_mutex_waiter *waiter;
+
+ /*
+ * This branch gets optimized out for the common case,
+ * and is only important for ww_mutex_lock.
+ */
+ ww_mutex_lock_acquired(ww, ww_ctx);
+ ww->ctx = ww_ctx;
+
+ /*
+ * Give any possible sleeping processes the chance to wake up,
+ * so they can recheck if they have to back off.
+ */
+ plist_for_each_entry(waiter, &lock->wait_list, list_entry) {
+
+ /* XXX debug rt mutex waiter wakeup */
+
+ BUG_ON(waiter->lock != lock);
+ rt_mutex_wake_waiter(waiter);
+ }
+}
+
+#else
+
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+ struct ww_acquire_ctx *ww_ctx)
+{
+ BUG();
+}
+#endif
+
/*
* Slow path lock function:
*/
static int __sched
rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- int detect_deadlock)
+ int detect_deadlock, struct ww_acquire_ctx *ww_ctx)
{
struct rt_mutex_waiter waiter;
int ret = 0;
- debug_rt_mutex_init_waiter(&waiter);
+ rt_mutex_init_waiter(&waiter, false);
raw_spin_lock(&lock->wait_lock);
+ init_lists(lock);
/* Try to acquire the lock again: */
if (try_to_take_rt_mutex(lock, current, NULL)) {
+ if (ww_ctx)
+ ww_mutex_account_lock(lock, ww_ctx);
raw_spin_unlock(&lock->wait_lock);
return 0;
}
@@ -659,12 +1179,14 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
ret = task_blocks_on_rt_mutex(lock, &waiter, current, detect_deadlock);
if (likely(!ret))
- ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
+ ret = __rt_mutex_slowlock(lock, state, timeout, &waiter, ww_ctx);
set_current_state(TASK_RUNNING);
if (unlikely(ret))
remove_waiter(lock, &waiter);
+ else if (ww_ctx)
+ ww_mutex_account_lock(lock, ww_ctx);
/*
* try_to_take_rt_mutex() sets the waiter bit
@@ -691,7 +1213,9 @@ rt_mutex_slowtrylock(struct rt_mutex *lock)
{
int ret = 0;
- raw_spin_lock(&lock->wait_lock);
+ if (!raw_spin_trylock(&lock->wait_lock))
+ return ret;
+ init_lists(lock);
if (likely(rt_mutex_owner(lock) != current)) {
@@ -742,30 +1266,33 @@ rt_mutex_slowunlock(struct rt_mutex *lock)
*/
static inline int
rt_mutex_fastlock(struct rt_mutex *lock, int state,
- int detect_deadlock,
+ int detect_deadlock, struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- int detect_deadlock))
+ int detect_deadlock,
+ struct ww_acquire_ctx *ww_ctx))
{
if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
rt_mutex_deadlock_account_lock(lock, current);
return 0;
} else
- return slowfn(lock, state, NULL, detect_deadlock);
+ return slowfn(lock, state, NULL, detect_deadlock, ww_ctx);
}
static inline int
rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout, int detect_deadlock,
+ struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- int detect_deadlock))
+ int detect_deadlock,
+ struct ww_acquire_ctx *ww_ctx))
{
if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
rt_mutex_deadlock_account_lock(lock, current);
return 0;
} else
- return slowfn(lock, state, timeout, detect_deadlock);
+ return slowfn(lock, state, timeout, detect_deadlock, ww_ctx);
}
static inline int
@@ -798,19 +1325,19 @@ void __sched rt_mutex_lock(struct rt_mutex *lock)
{
might_sleep();
- rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, 0, rt_mutex_slowlock);
+ rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, 0, NULL, rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock);
/**
* rt_mutex_lock_interruptible - lock a rt_mutex interruptible
*
- * @lock: the rt_mutex to be locked
+ * @lock: the rt_mutex to be locked
* @detect_deadlock: deadlock detection on/off
*
* Returns:
- * 0 on success
- * -EINTR when interrupted by a signal
+ * 0 on success
+ * -EINTR when interrupted by a signal
* -EDEADLK when the lock would deadlock (when deadlock detection is on)
*/
int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock,
@@ -819,22 +1346,43 @@ int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock,
might_sleep();
return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE,
- detect_deadlock, rt_mutex_slowlock);
+ detect_deadlock, NULL, rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
/**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock: the rt_mutex to be locked
+ * @detect_deadlock: deadlock detection on/off
+ *
+ * Returns:
+ * 0 on success
+ * -EINTR when interrupted by a signal
+ * -EDEADLK when the lock would deadlock (when deadlock detection is on)
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock,
+ int detect_deadlock)
+{
+ might_sleep();
+
+ return rt_mutex_fastlock(lock, TASK_KILLABLE,
+ detect_deadlock, NULL, rt_mutex_slowlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
+/**
* rt_mutex_timed_lock - lock a rt_mutex interruptible
* the timeout structure is provided
* by the caller
*
- * @lock: the rt_mutex to be locked
+ * @lock: the rt_mutex to be locked
* @timeout: timeout structure or NULL (no timeout)
* @detect_deadlock: deadlock detection on/off
*
* Returns:
- * 0 on success
- * -EINTR when interrupted by a signal
+ * 0 on success
+ * -EINTR when interrupted by a signal
* -ETIMEDOUT when the timeout expired
* -EDEADLK when the lock would deadlock (when deadlock detection is on)
*/
@@ -845,7 +1393,7 @@ rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout,
might_sleep();
return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
- detect_deadlock, rt_mutex_slowlock);
+ detect_deadlock, NULL, rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
@@ -903,12 +1451,11 @@ EXPORT_SYMBOL_GPL(rt_mutex_destroy);
void __rt_mutex_init(struct rt_mutex *lock, const char *name)
{
lock->owner = NULL;
- raw_spin_lock_init(&lock->wait_lock);
plist_head_init(&lock->wait_list);
debug_rt_mutex_init(lock, name);
}
-EXPORT_SYMBOL_GPL(__rt_mutex_init);
+EXPORT_SYMBOL(__rt_mutex_init);
/**
* rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
@@ -923,7 +1470,7 @@ EXPORT_SYMBOL_GPL(__rt_mutex_init);
void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner)
{
- __rt_mutex_init(lock, NULL);
+ rt_mutex_init(lock);
debug_rt_mutex_proxy_lock(lock, proxy_owner);
rt_mutex_set_owner(lock, proxy_owner);
rt_mutex_deadlock_account_lock(lock, proxy_owner);
@@ -972,6 +1519,35 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
return 1;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /*
+ * In PREEMPT_RT there's an added race.
+ * If the task, that we are about to requeue, times out,
+ * it can set the PI_WAKEUP_INPROGRESS. This tells the requeue
+ * to skip this task. But right after the task sets
+ * its pi_blocked_on to PI_WAKEUP_INPROGRESS it can then
+ * block on the spin_lock(&hb->lock), which in RT is an rtmutex.
+ * This will replace the PI_WAKEUP_INPROGRESS with the actual
+ * lock that it blocks on. We *must not* place this task
+ * on this proxy lock in that case.
+ *
+ * To prevent this race, we first take the task's pi_lock
+ * and check if it has updated its pi_blocked_on. If it has,
+ * we assume that it woke up and we return -EAGAIN.
+ * Otherwise, we set the task's pi_blocked_on to
+ * PI_REQUEUE_INPROGRESS, so that if the task is waking up
+ * it will know that we are in the process of requeuing it.
+ */
+ raw_spin_lock_irq(&task->pi_lock);
+ if (task->pi_blocked_on) {
+ raw_spin_unlock_irq(&task->pi_lock);
+ raw_spin_unlock(&lock->wait_lock);
+ return -EAGAIN;
+ }
+ task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
+ raw_spin_unlock_irq(&task->pi_lock);
+#endif
+
ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);
if (ret && !rt_mutex_owner(lock)) {
@@ -1041,7 +1617,7 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
set_current_state(TASK_INTERRUPTIBLE);
- ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter);
+ ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter, NULL);
set_current_state(TASK_RUNNING);
@@ -1058,3 +1634,88 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
return ret;
}
+
+static inline int
+ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+ unsigned tmp;
+
+ if (ctx->deadlock_inject_countdown-- == 0) {
+ tmp = ctx->deadlock_inject_interval;
+ if (tmp > UINT_MAX/4)
+ tmp = UINT_MAX;
+ else
+ tmp = tmp*2 + tmp + tmp/2;
+
+ ctx->deadlock_inject_interval = tmp;
+ ctx->deadlock_inject_countdown = tmp;
+ ctx->contending_lock = lock;
+
+ ww_mutex_unlock(lock);
+
+ return -EDEADLK;
+ }
+#endif
+
+ return 0;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+int __sched
+__ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx)
+{
+ int ret;
+
+ might_sleep();
+
+ mutex_acquire(&lock->base.dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, 0, ww_ctx);
+ if (ret)
+ mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+ else if (!ret && ww_ctx->acquired > 1)
+ return ww_mutex_deadlock_injection(lock, ww_ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__ww_mutex_lock_interruptible);
+
+int __sched
+__ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx)
+{
+ int ret;
+
+ might_sleep();
+
+ mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map,
+ _RET_IP_);
+ ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, 0, ww_ctx);
+ if (ret)
+ mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+ else if (!ret && ww_ctx->acquired > 1)
+ return ww_mutex_deadlock_injection(lock, ww_ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__ww_mutex_lock);
+
+void __sched ww_mutex_unlock(struct ww_mutex *lock)
+{
+ /*
+ * The unlocking fastpath is the 0->1 transition from 'locked'
+ * into 'unlocked' state:
+ */
+ if (lock->ctx) {
+#ifdef CONFIG_DEBUG_MUTEXES
+ DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired);
+#endif
+ if (lock->ctx->acquired > 0)
+ lock->ctx->acquired--;
+ lock->ctx = NULL;
+ }
+
+ mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+ rt_mutex_unlock(&lock->base.lock);
+}
+EXPORT_SYMBOL(ww_mutex_unlock);
+#endif
diff --git a/kernel/rtmutex_common.h b/kernel/rtmutex_common.h
index 53a66c8..6ec3dc1 100644
--- a/kernel/rtmutex_common.h
+++ b/kernel/rtmutex_common.h
@@ -49,6 +49,7 @@ struct rt_mutex_waiter {
struct plist_node pi_list_entry;
struct task_struct *task;
struct rt_mutex *lock;
+ bool savestate;
#ifdef CONFIG_DEBUG_RT_MUTEXES
unsigned long ip;
struct pid *deadlock_task_pid;
@@ -103,6 +104,9 @@ static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
/*
* PI-futex support (proxy locking functions, etc.):
*/
+#define PI_WAKEUP_INPROGRESS ((struct rt_mutex_waiter *) 1)
+#define PI_REQUEUE_INPROGRESS ((struct rt_mutex_waiter *) 2)
+
extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner);
@@ -123,4 +127,12 @@ extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
# include "rtmutex.h"
#endif
+static inline void
+rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savestate)
+{
+ debug_rt_mutex_init_waiter(waiter);
+ waiter->task = NULL;
+ waiter->savestate = savestate;
+}
+
#endif
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a494ace..8749d20 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -272,7 +272,11 @@ late_initcall(sched_init_debug);
* Number of tasks to iterate in a single balance run.
* Limited because this is done with IRQs disabled.
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
const_debug unsigned int sysctl_sched_nr_migrate = 32;
+#else
+const_debug unsigned int sysctl_sched_nr_migrate = 8;
+#endif
/*
* period over which we average the RT time consumption, measured
@@ -491,6 +495,7 @@ static void init_rq_hrtick(struct rq *rq)
hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
rq->hrtick_timer.function = hrtick;
+ rq->hrtick_timer.irqsafe = 1;
}
#else /* CONFIG_SCHED_HRTICK */
static inline void hrtick_clear(struct rq *rq)
@@ -535,6 +540,37 @@ void resched_task(struct task_struct *p)
smp_send_reschedule(cpu);
}
+#ifdef CONFIG_PREEMPT_LAZY
+void resched_task_lazy(struct task_struct *p)
+{
+ int cpu;
+
+ if (!sched_feat(PREEMPT_LAZY)) {
+ resched_task(p);
+ return;
+ }
+
+ assert_raw_spin_locked(&task_rq(p)->lock);
+
+ if (test_tsk_need_resched(p))
+ return;
+
+ if (test_tsk_need_resched_lazy(p))
+ return;
+
+ set_tsk_need_resched_lazy(p);
+
+ cpu = task_cpu(p);
+ if (cpu == smp_processor_id())
+ return;
+
+ /* NEED_RESCHED_LAZY must be visible before we test polling */
+ smp_mb();
+ if (!tsk_is_polling(p))
+ smp_send_reschedule(cpu);
+}
+#endif
+
void resched_cpu(int cpu)
{
struct rq *rq = cpu_rq(cpu);
@@ -699,6 +735,17 @@ void resched_task(struct task_struct *p)
assert_raw_spin_locked(&task_rq(p)->lock);
set_tsk_need_resched(p);
}
+#ifdef CONFIG_PREEMPT_LAZY
+void resched_task_lazy(struct task_struct *p)
+{
+ if (!sched_feat(PREEMPT_LAZY)) {
+ resched_task(p);
+ return;
+ }
+ assert_raw_spin_locked(&task_rq(p)->lock);
+ set_tsk_need_resched_lazy(p);
+}
+#endif
#endif /* CONFIG_SMP */
#if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
@@ -1024,6 +1071,18 @@ struct migration_arg {
static int migration_cpu_stop(void *data);
+static bool check_task_state(struct task_struct *p, long match_state)
+{
+ bool match = false;
+
+ raw_spin_lock_irq(&p->pi_lock);
+ if (p->state == match_state || p->saved_state == match_state)
+ match = true;
+ raw_spin_unlock_irq(&p->pi_lock);
+
+ return match;
+}
+
/*
* wait_task_inactive - wait for a thread to unschedule.
*
@@ -1068,7 +1127,7 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
* is actually now running somewhere else!
*/
while (task_running(rq, p)) {
- if (match_state && unlikely(p->state != match_state))
+ if (match_state && !check_task_state(p, match_state))
return 0;
cpu_relax();
}
@@ -1083,7 +1142,8 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
running = task_running(rq, p);
on_rq = p->on_rq;
ncsw = 0;
- if (!match_state || p->state == match_state)
+ if (!match_state || p->state == match_state
+ || p->saved_state == match_state)
ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
task_rq_unlock(rq, p, &flags);
@@ -1229,6 +1289,12 @@ out:
}
}
+ /*
+ * Clear PF_NO_SETAFFINITY, otherwise we wreckage
+ * migrate_disable/enable. See optimization for
+ * PF_NO_SETAFFINITY tasks there.
+ */
+ p->flags &= ~PF_NO_SETAFFINITY;
return dest_cpu;
}
@@ -1308,10 +1374,6 @@ static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
{
activate_task(rq, p, en_flags);
p->on_rq = 1;
-
- /* if a worker is waking up, notify workqueue */
- if (p->flags & PF_WQ_WORKER)
- wq_worker_waking_up(p, cpu_of(rq));
}
/*
@@ -1486,8 +1548,27 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
*/
smp_mb__before_spinlock();
raw_spin_lock_irqsave(&p->pi_lock, flags);
- if (!(p->state & state))
+ if (!(p->state & state)) {
+ /*
+ * The task might be running due to a spinlock sleeper
+ * wakeup. Check the saved state and set it to running
+ * if the wakeup condition is true.
+ */
+ if (!(wake_flags & WF_LOCK_SLEEPER)) {
+ if (p->saved_state & state) {
+ p->saved_state = TASK_RUNNING;
+ success = 1;
+ }
+ }
goto out;
+ }
+
+ /*
+ * If this is a regular wakeup, then we can unconditionally
+ * clear the saved state of a "lock sleeper".
+ */
+ if (!(wake_flags & WF_LOCK_SLEEPER))
+ p->saved_state = TASK_RUNNING;
success = 1; /* we're going to change ->state */
cpu = task_cpu(p);
@@ -1530,42 +1611,6 @@ out:
}
/**
- * try_to_wake_up_local - try to wake up a local task with rq lock held
- * @p: the thread to be awakened
- *
- * Put @p on the run-queue if it's not already there. The caller must
- * ensure that this_rq() is locked, @p is bound to this_rq() and not
- * the current task.
- */
-static void try_to_wake_up_local(struct task_struct *p)
-{
- struct rq *rq = task_rq(p);
-
- if (WARN_ON_ONCE(rq != this_rq()) ||
- WARN_ON_ONCE(p == current))
- return;
-
- lockdep_assert_held(&rq->lock);
-
- if (!raw_spin_trylock(&p->pi_lock)) {
- raw_spin_unlock(&rq->lock);
- raw_spin_lock(&p->pi_lock);
- raw_spin_lock(&rq->lock);
- }
-
- if (!(p->state & TASK_NORMAL))
- goto out;
-
- if (!p->on_rq)
- ttwu_activate(rq, p, ENQUEUE_WAKEUP);
-
- ttwu_do_wakeup(rq, p, 0);
- ttwu_stat(p, smp_processor_id(), 0);
-out:
- raw_spin_unlock(&p->pi_lock);
-}
-
-/**
* wake_up_process - Wake up a specific process
* @p: The process to be woken up.
*
@@ -1579,11 +1624,23 @@ out:
*/
int wake_up_process(struct task_struct *p)
{
- WARN_ON(task_is_stopped_or_traced(p));
+ WARN_ON(__task_is_stopped_or_traced(p));
return try_to_wake_up(p, TASK_NORMAL, 0);
}
EXPORT_SYMBOL(wake_up_process);
+/**
+ * wake_up_lock_sleeper - Wake up a specific process blocked on a "sleeping lock"
+ * @p: The process to be woken up.
+ *
+ * Same as wake_up_process() above, but wake_flags=WF_LOCK_SLEEPER to indicate
+ * the nature of the wakeup.
+ */
+int wake_up_lock_sleeper(struct task_struct *p)
+{
+ return try_to_wake_up(p, TASK_ALL, WF_LOCK_SLEEPER);
+}
+
int wake_up_state(struct task_struct *p, unsigned int state)
{
return try_to_wake_up(p, state, 0);
@@ -1721,6 +1778,9 @@ void sched_fork(struct task_struct *p)
/* Want to start with kernel preemption disabled. */
task_thread_info(p)->preempt_count = 1;
#endif
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+ task_thread_info(p)->preempt_lazy_count = 0;
+#endif
#ifdef CONFIG_SMP
plist_node_init(&p->pushable_tasks, MAX_PRIO);
#endif
@@ -1887,8 +1947,12 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
finish_arch_post_lock_switch();
fire_sched_in_preempt_notifiers(current);
+ /*
+ * We use mmdrop_delayed() here so we don't have to do the
+ * full __mmdrop() when we are the last user.
+ */
if (mm)
- mmdrop(mm);
+ mmdrop_delayed(mm);
if (unlikely(prev_state == TASK_DEAD)) {
/*
* Remove function-return probe instances associated with this
@@ -2232,8 +2296,13 @@ void __kprobes add_preempt_count(int val)
DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
PREEMPT_MASK - 10);
#endif
- if (preempt_count() == val)
- trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ if (preempt_count() == val) {
+ unsigned long ip = get_parent_ip(CALLER_ADDR1);
+#ifdef CONFIG_DEBUG_PREEMPT
+ current->preempt_disable_ip = ip;
+#endif
+ trace_preempt_off(CALLER_ADDR0, ip);
+ }
}
EXPORT_SYMBOL(add_preempt_count);
@@ -2276,6 +2345,13 @@ static noinline void __schedule_bug(struct task_struct *prev)
print_modules();
if (irqs_disabled())
print_irqtrace_events(prev);
+#ifdef CONFIG_DEBUG_PREEMPT
+ if (in_atomic_preempt_off()) {
+ pr_err("Preemption disabled at:");
+ print_ip_sym(current->preempt_disable_ip);
+ pr_cont("\n");
+ }
+#endif
dump_stack();
add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
}
@@ -2299,6 +2375,133 @@ static inline void schedule_debug(struct task_struct *prev)
schedstat_inc(this_rq(), sched_count);
}
+#if defined(CONFIG_PREEMPT_RT_FULL) && defined(CONFIG_SMP)
+#define MIGRATE_DISABLE_SET_AFFIN (1<<30) /* Can't make a negative */
+#define migrate_disabled_updated(p) ((p)->migrate_disable & MIGRATE_DISABLE_SET_AFFIN)
+#define migrate_disable_count(p) ((p)->migrate_disable & ~MIGRATE_DISABLE_SET_AFFIN)
+
+static inline void update_migrate_disable(struct task_struct *p)
+{
+ const struct cpumask *mask;
+
+ if (likely(!p->migrate_disable))
+ return;
+
+ /* Did we already update affinity? */
+ if (unlikely(migrate_disabled_updated(p)))
+ return;
+
+ /*
+ * Since this is always current we can get away with only locking
+ * rq->lock, the ->cpus_allowed value can normally only be changed
+ * while holding both p->pi_lock and rq->lock, but seeing that this
+ * is current, we cannot actually be waking up, so all code that
+ * relies on serialization against p->pi_lock is out of scope.
+ *
+ * Having rq->lock serializes us against things like
+ * set_cpus_allowed_ptr() that can still happen concurrently.
+ */
+ mask = tsk_cpus_allowed(p);
+
+ if (p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, mask);
+ /* mask==cpumask_of(task_cpu(p)) which has a cpumask_weight==1 */
+ p->nr_cpus_allowed = 1;
+
+ /* Let migrate_enable know to fix things back up */
+ p->migrate_disable |= MIGRATE_DISABLE_SET_AFFIN;
+}
+
+void migrate_disable(void)
+{
+ struct task_struct *p = current;
+
+ if (in_atomic()) {
+#ifdef CONFIG_SCHED_DEBUG
+ p->migrate_disable_atomic++;
+#endif
+ return;
+ }
+
+#ifdef CONFIG_SCHED_DEBUG
+ if (unlikely(p->migrate_disable_atomic)) {
+ tracing_off();
+ WARN_ON_ONCE(1);
+ }
+#endif
+
+ if (p->migrate_disable) {
+ p->migrate_disable++;
+ return;
+ }
+
+ preempt_disable();
+ preempt_lazy_disable();
+ pin_current_cpu();
+ p->migrate_disable = 1;
+ preempt_enable();
+}
+EXPORT_SYMBOL(migrate_disable);
+
+void migrate_enable(void)
+{
+ struct task_struct *p = current;
+ const struct cpumask *mask;
+ unsigned long flags;
+ struct rq *rq;
+
+ if (in_atomic()) {
+#ifdef CONFIG_SCHED_DEBUG
+ p->migrate_disable_atomic--;
+#endif
+ return;
+ }
+
+#ifdef CONFIG_SCHED_DEBUG
+ if (unlikely(p->migrate_disable_atomic)) {
+ tracing_off();
+ WARN_ON_ONCE(1);
+ }
+#endif
+ WARN_ON_ONCE(p->migrate_disable <= 0);
+
+ if (migrate_disable_count(p) > 1) {
+ p->migrate_disable--;
+ return;
+ }
+
+ preempt_disable();
+ if (unlikely(migrate_disabled_updated(p))) {
+ /*
+ * Undo whatever update_migrate_disable() did, also see there
+ * about locking.
+ */
+ rq = this_rq();
+ raw_spin_lock_irqsave(&rq->lock, flags);
+
+ /*
+ * Clearing migrate_disable causes tsk_cpus_allowed to
+ * show the tasks original cpu affinity.
+ */
+ p->migrate_disable = 0;
+ mask = tsk_cpus_allowed(p);
+ if (p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, mask);
+ p->nr_cpus_allowed = cpumask_weight(mask);
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+ } else
+ p->migrate_disable = 0;
+
+ unpin_current_cpu();
+ preempt_enable();
+ preempt_lazy_enable();
+}
+EXPORT_SYMBOL(migrate_enable);
+#else
+static inline void update_migrate_disable(struct task_struct *p) { }
+#define migrate_disabled_updated(p) 0
+#endif
+
static void put_prev_task(struct rq *rq, struct task_struct *prev)
{
if (prev->on_rq || rq->skip_clock_update < 0)
@@ -2398,6 +2601,8 @@ need_resched:
smp_mb__before_spinlock();
raw_spin_lock_irq(&rq->lock);
+ update_migrate_disable(prev);
+
switch_count = &prev->nivcsw;
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
if (unlikely(signal_pending_state(prev->state, prev))) {
@@ -2405,19 +2610,6 @@ need_resched:
} else {
deactivate_task(rq, prev, DEQUEUE_SLEEP);
prev->on_rq = 0;
-
- /*
- * If a worker went to sleep, notify and ask workqueue
- * whether it wants to wake up a task to maintain
- * concurrency.
- */
- if (prev->flags & PF_WQ_WORKER) {
- struct task_struct *to_wakeup;
-
- to_wakeup = wq_worker_sleeping(prev, cpu);
- if (to_wakeup)
- try_to_wake_up_local(to_wakeup);
- }
}
switch_count = &prev->nvcsw;
}
@@ -2430,6 +2622,7 @@ need_resched:
put_prev_task(rq, prev);
next = pick_next_task(rq);
clear_tsk_need_resched(prev);
+ clear_tsk_need_resched_lazy(prev);
rq->skip_clock_update = 0;
if (likely(prev != next)) {
@@ -2460,6 +2653,14 @@ static inline void sched_submit_work(struct task_struct *tsk)
{
if (!tsk->state || tsk_is_pi_blocked(tsk))
return;
+
+ /*
+ * If a worker went to sleep, notify and ask workqueue whether
+ * it wants to wake up a task to maintain concurrency.
+ */
+ if (tsk->flags & PF_WQ_WORKER)
+ wq_worker_sleeping(tsk);
+
/*
* If we are going to sleep and we have plugged IO queued,
* make sure to submit it to avoid deadlocks.
@@ -2468,12 +2669,19 @@ static inline void sched_submit_work(struct task_struct *tsk)
blk_schedule_flush_plug(tsk);
}
+static inline void sched_update_worker(struct task_struct *tsk)
+{
+ if (tsk->flags & PF_WQ_WORKER)
+ wq_worker_running(tsk);
+}
+
asmlinkage void __sched schedule(void)
{
struct task_struct *tsk = current;
sched_submit_work(tsk);
__schedule();
+ sched_update_worker(tsk);
}
EXPORT_SYMBOL(schedule);
@@ -2519,9 +2727,26 @@ asmlinkage void __sched notrace preempt_schedule(void)
if (likely(!preemptible()))
return;
+#ifdef CONFIG_PREEMPT_LAZY
+ /*
+ * Check for lazy preemption
+ */
+ if (current_thread_info()->preempt_lazy_count &&
+ !test_thread_flag(TIF_NEED_RESCHED))
+ return;
+#endif
do {
add_preempt_count_notrace(PREEMPT_ACTIVE);
+ /*
+ * The add/subtract must not be traced by the function
+ * tracer. But we still want to account for the
+ * preempt off latency tracer. Since the _notrace versions
+ * of add/subtract skip the accounting for latency tracer
+ * we must force it manually.
+ */
+ start_critical_timings();
__schedule();
+ stop_critical_timings();
sub_preempt_count_notrace(PREEMPT_ACTIVE);
/*
@@ -2694,10 +2919,10 @@ void complete(struct completion *x)
{
unsigned long flags;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
- __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ __swait_wake_locked(&x->wait, TASK_NORMAL, 1);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete);
@@ -2714,10 +2939,10 @@ void complete_all(struct completion *x)
{
unsigned long flags;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
- __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ __swait_wake_locked(&x->wait, TASK_NORMAL, 0);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete_all);
@@ -2726,20 +2951,20 @@ do_wait_for_common(struct completion *x,
long (*action)(long), long timeout, int state)
{
if (!x->done) {
- DECLARE_WAITQUEUE(wait, current);
+ DEFINE_SWAITER(wait);
- __add_wait_queue_tail_exclusive(&x->wait, &wait);
+ swait_prepare_locked(&x->wait, &wait);
do {
if (signal_pending_state(state, current)) {
timeout = -ERESTARTSYS;
break;
}
__set_current_state(state);
- spin_unlock_irq(&x->wait.lock);
+ raw_spin_unlock_irq(&x->wait.lock);
timeout = action(timeout);
- spin_lock_irq(&x->wait.lock);
+ raw_spin_lock_irq(&x->wait.lock);
} while (!x->done && timeout);
- __remove_wait_queue(&x->wait, &wait);
+ swait_finish_locked(&x->wait, &wait);
if (!x->done)
return timeout;
}
@@ -2753,9 +2978,9 @@ __wait_for_common(struct completion *x,
{
might_sleep();
- spin_lock_irq(&x->wait.lock);
+ raw_spin_lock_irq(&x->wait.lock);
timeout = do_wait_for_common(x, action, timeout, state);
- spin_unlock_irq(&x->wait.lock);
+ raw_spin_unlock_irq(&x->wait.lock);
return timeout;
}
@@ -2931,12 +3156,12 @@ bool try_wait_for_completion(struct completion *x)
unsigned long flags;
int ret = 1;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
else
x->done--;
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(try_wait_for_completion);
@@ -2954,10 +3179,10 @@ bool completion_done(struct completion *x)
unsigned long flags;
int ret = 1;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(completion_done);
@@ -3018,7 +3243,8 @@ EXPORT_SYMBOL(sleep_on_timeout);
* This function changes the 'effective' priority of a task. It does
* not touch ->normal_prio like __setscheduler().
*
- * Used by the rt_mutex code to implement priority inheritance logic.
+ * Used by the rt_mutex code to implement priority inheritance
+ * logic. Call site only calls if the priority of the task changed.
*/
void rt_mutex_setprio(struct task_struct *p, int prio)
{
@@ -3249,20 +3475,25 @@ static struct task_struct *find_process_by_pid(pid_t pid)
return pid ? find_task_by_vpid(pid) : current;
}
-/* Actually do priority change: must hold rq lock. */
-static void
-__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
+static void __setscheduler_params(struct task_struct *p, int policy, int prio)
{
p->policy = policy;
p->rt_priority = prio;
p->normal_prio = normal_prio(p);
+ set_load_weight(p);
+}
+
+/* Actually do priority change: must hold rq lock. */
+static void
+__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
+{
+ __setscheduler_params(p, policy, prio);
/* we are holding p->pi_lock already */
p->prio = rt_mutex_getprio(p);
if (rt_prio(p->prio))
p->sched_class = &rt_sched_class;
else
p->sched_class = &fair_sched_class;
- set_load_weight(p);
}
/*
@@ -3284,6 +3515,7 @@ static bool check_same_owner(struct task_struct *p)
static int __sched_setscheduler(struct task_struct *p, int policy,
const struct sched_param *param, bool user)
{
+ int newprio = MAX_RT_PRIO - 1 - param->sched_priority;
int retval, oldprio, oldpolicy = -1, on_rq, running;
unsigned long flags;
const struct sched_class *prev_class;
@@ -3379,10 +3611,13 @@ recheck:
}
/*
- * If not changing anything there's no need to proceed further:
+ * If not changing anything there's no need to proceed
+ * further, but store a possible modification of
+ * reset_on_fork.
*/
if (unlikely(policy == p->policy && (!rt_policy(policy) ||
param->sched_priority == p->rt_priority))) {
+ p->sched_reset_on_fork = reset_on_fork;
task_rq_unlock(rq, p, &flags);
return 0;
}
@@ -3408,6 +3643,25 @@ recheck:
task_rq_unlock(rq, p, &flags);
goto recheck;
}
+
+ p->sched_reset_on_fork = reset_on_fork;
+ oldprio = p->prio;
+
+ /*
+ * Special case for priority boosted tasks.
+ *
+ * If the new priority is lower or equal (user space view)
+ * than the current (boosted) priority, we just store the new
+ * normal parameters and do not touch the scheduler class and
+ * the runqueue. This will be done when the task deboost
+ * itself.
+ */
+ if (rt_mutex_check_prio(p, newprio)) {
+ __setscheduler_params(p, policy, param->sched_priority);
+ task_rq_unlock(rq, p, &flags);
+ return 0;
+ }
+
on_rq = p->on_rq;
running = task_current(rq, p);
if (on_rq)
@@ -3415,17 +3669,18 @@ recheck:
if (running)
p->sched_class->put_prev_task(rq, p);
- p->sched_reset_on_fork = reset_on_fork;
-
- oldprio = p->prio;
prev_class = p->sched_class;
__setscheduler(rq, p, policy, param->sched_priority);
if (running)
p->sched_class->set_curr_task(rq);
- if (on_rq)
- enqueue_task(rq, p, 0);
-
+ if (on_rq) {
+ /*
+ * We enqueue to tail when the priority of a task is
+ * increased (user space view).
+ */
+ enqueue_task(rq, p, oldprio <= p->prio ? ENQUEUE_HEAD : 0);
+ }
check_class_changed(rq, p, prev_class, oldprio);
task_rq_unlock(rq, p, &flags);
@@ -3801,9 +4056,17 @@ static inline int should_resched(void)
static void __cond_resched(void)
{
- add_preempt_count(PREEMPT_ACTIVE);
- __schedule();
- sub_preempt_count(PREEMPT_ACTIVE);
+ do {
+ add_preempt_count(PREEMPT_ACTIVE);
+ __schedule();
+ sub_preempt_count(PREEMPT_ACTIVE);
+ /*
+ * Check again in case we missed a preemption
+ * opportunity between schedule and now.
+ */
+ barrier();
+
+ } while (need_resched());
}
int __sched _cond_resched(void)
@@ -3844,6 +4107,7 @@ int __cond_resched_lock(spinlock_t *lock)
}
EXPORT_SYMBOL(__cond_resched_lock);
+#ifndef CONFIG_PREEMPT_RT_FULL
int __sched __cond_resched_softirq(void)
{
BUG_ON(!in_softirq());
@@ -3857,6 +4121,7 @@ int __sched __cond_resched_softirq(void)
return 0;
}
EXPORT_SYMBOL(__cond_resched_softirq);
+#endif
/**
* yield - yield the current processor to other threads.
@@ -4206,6 +4471,7 @@ void init_idle(struct task_struct *idle, int cpu)
rcu_read_unlock();
rq->curr = rq->idle = idle;
+ idle->on_rq = 1;
#if defined(CONFIG_SMP)
idle->on_cpu = 1;
#endif
@@ -4213,7 +4479,9 @@ void init_idle(struct task_struct *idle, int cpu)
/* Set the preempt count _outside_ the spinlocks! */
task_thread_info(idle)->preempt_count = 0;
-
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+ task_thread_info(idle)->preempt_lazy_count = 0;
+#endif
/*
* The idle tasks have their own, simple scheduling class:
*/
@@ -4228,11 +4496,90 @@ void init_idle(struct task_struct *idle, int cpu)
#ifdef CONFIG_SMP
void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
{
- if (p->sched_class && p->sched_class->set_cpus_allowed)
- p->sched_class->set_cpus_allowed(p, new_mask);
-
+ if (!migrate_disabled_updated(p)) {
+ if (p->sched_class && p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, new_mask);
+ p->nr_cpus_allowed = cpumask_weight(new_mask);
+ }
cpumask_copy(&p->cpus_allowed, new_mask);
- p->nr_cpus_allowed = cpumask_weight(new_mask);
+}
+
+static DEFINE_PER_CPU(struct cpumask, sched_cpumasks);
+static DEFINE_MUTEX(sched_down_mutex);
+static cpumask_t sched_down_cpumask;
+
+void tell_sched_cpu_down_begin(int cpu)
+{
+ mutex_lock(&sched_down_mutex);
+ cpumask_set_cpu(cpu, &sched_down_cpumask);
+ mutex_unlock(&sched_down_mutex);
+}
+
+void tell_sched_cpu_down_done(int cpu)
+{
+ mutex_lock(&sched_down_mutex);
+ cpumask_clear_cpu(cpu, &sched_down_cpumask);
+ mutex_unlock(&sched_down_mutex);
+}
+
+/**
+ * migrate_me - try to move the current task off this cpu
+ *
+ * Used by the pin_current_cpu() code to try to get tasks
+ * to move off the current CPU as it is going down.
+ * It will only move the task if the task isn't pinned to
+ * the CPU (with migrate_disable, affinity or NO_SETAFFINITY)
+ * and the task has to be in a RUNNING state. Otherwise the
+ * movement of the task will wake it up (change its state
+ * to running) when the task did not expect it.
+ *
+ * Returns 1 if it succeeded in moving the current task
+ * 0 otherwise.
+ */
+int migrate_me(void)
+{
+ struct task_struct *p = current;
+ struct migration_arg arg;
+ struct cpumask *cpumask;
+ struct cpumask *mask;
+ unsigned long flags;
+ unsigned int dest_cpu;
+ struct rq *rq;
+
+ /*
+ * We can not migrate tasks bounded to a CPU or tasks not
+ * running. The movement of the task will wake it up.
+ */
+ if (p->flags & PF_NO_SETAFFINITY || p->state)
+ return 0;
+
+ mutex_lock(&sched_down_mutex);
+ rq = task_rq_lock(p, &flags);
+
+ cpumask = &__get_cpu_var(sched_cpumasks);
+ mask = &p->cpus_allowed;
+
+ cpumask_andnot(cpumask, mask, &sched_down_cpumask);
+
+ if (!cpumask_weight(cpumask)) {
+ /* It's only on this CPU? */
+ task_rq_unlock(rq, p, &flags);
+ mutex_unlock(&sched_down_mutex);
+ return 0;
+ }
+
+ dest_cpu = cpumask_any_and(cpu_active_mask, cpumask);
+
+ arg.task = p;
+ arg.dest_cpu = dest_cpu;
+
+ task_rq_unlock(rq, p, &flags);
+
+ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
+ tlb_migrate_finish(p->mm);
+ mutex_unlock(&sched_down_mutex);
+
+ return 1;
}
/*
@@ -4278,7 +4625,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
do_set_cpus_allowed(p, new_mask);
/* Can the task run on the task's current CPU? If so, we're done */
- if (cpumask_test_cpu(task_cpu(p), new_mask))
+ if (cpumask_test_cpu(task_cpu(p), new_mask) || __migrate_disabled(p))
goto out;
dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
@@ -4367,6 +4714,8 @@ static int migration_cpu_stop(void *data)
#ifdef CONFIG_HOTPLUG_CPU
+static DEFINE_PER_CPU(struct mm_struct *, idle_last_mm);
+
/*
* Ensures that the idle task is using init_mm right before its cpu goes
* offline.
@@ -4379,7 +4728,12 @@ void idle_task_exit(void)
if (mm != &init_mm)
switch_mm(mm, &init_mm, current);
- mmdrop(mm);
+
+ /*
+ * Defer the cleanup to an alive cpu. On RT we can neither
+ * call mmdrop() nor mmdrop_delayed() from here.
+ */
+ per_cpu(idle_last_mm, smp_processor_id()) = mm;
}
/*
@@ -4703,6 +5057,10 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
case CPU_DEAD:
calc_load_migrate(rq);
+ if (per_cpu(idle_last_mm, cpu)) {
+ mmdrop(per_cpu(idle_last_mm, cpu));
+ per_cpu(idle_last_mm, cpu) = NULL;
+ }
break;
#endif
}
@@ -6575,7 +6933,8 @@ void __init sched_init(void)
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
static inline int preempt_count_equals(int preempt_offset)
{
- int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
+ int nested = (preempt_count() & ~PREEMPT_ACTIVE) +
+ sched_rcu_preempt_depth();
return (nested == preempt_offset);
}
@@ -6585,7 +6944,8 @@ void __might_sleep(const char *file, int line, int preempt_offset)
static unsigned long prev_jiffy; /* ratelimiting */
rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
- if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
+ if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
+ !is_idle_task(current)) ||
system_state != SYSTEM_RUNNING || oops_in_progress)
return;
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
@@ -6603,6 +6963,13 @@ void __might_sleep(const char *file, int line, int preempt_offset)
debug_show_held_locks(current);
if (irqs_disabled())
print_irqtrace_events(current);
+#ifdef CONFIG_DEBUG_PREEMPT
+ if (!preempt_count_equals(preempt_offset)) {
+ pr_err("Preemption disabled at:");
+ print_ip_sym(current->preempt_disable_ip);
+ pr_cont("\n");
+ }
+#endif
dump_stack();
}
EXPORT_SYMBOL(__might_sleep);
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 9994791..1681f49 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -655,37 +655,45 @@ static void __vtime_account_system(struct task_struct *tsk)
void vtime_account_system(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_gen_account_irq_exit(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_account_user(struct task_struct *tsk)
{
cputime_t delta_cpu;
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
delta_cpu = get_vtime_delta(tsk);
tsk->vtime_snap_whence = VTIME_SYS;
account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_user_enter(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
tsk->vtime_snap_whence = VTIME_USER;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_guest_enter(struct task_struct *tsk)
@@ -697,19 +705,23 @@ void vtime_guest_enter(struct task_struct *tsk)
* synchronization against the reader (task_gtime())
* that can thus safely catch up with a tickless delta.
*/
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
current->flags |= PF_VCPU;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
EXPORT_SYMBOL_GPL(vtime_guest_enter);
void vtime_guest_exit(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
current->flags &= ~PF_VCPU;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
EXPORT_SYMBOL_GPL(vtime_guest_exit);
@@ -722,24 +734,30 @@ void vtime_account_idle(struct task_struct *tsk)
void arch_vtime_task_switch(struct task_struct *prev)
{
- write_seqlock(&prev->vtime_seqlock);
+ raw_spin_lock(&prev->vtime_lock);
+ write_seqcount_begin(&prev->vtime_seq);
prev->vtime_snap_whence = VTIME_SLEEPING;
- write_sequnlock(&prev->vtime_seqlock);
+ write_seqcount_end(&prev->vtime_seq);
+ raw_spin_unlock(&prev->vtime_lock);
- write_seqlock(&current->vtime_seqlock);
+ raw_spin_lock(&current->vtime_lock);
+ write_seqcount_begin(&current->vtime_seq);
current->vtime_snap_whence = VTIME_SYS;
current->vtime_snap = sched_clock_cpu(smp_processor_id());
- write_sequnlock(&current->vtime_seqlock);
+ write_seqcount_end(&current->vtime_seq);
+ raw_spin_unlock(&current->vtime_lock);
}
void vtime_init_idle(struct task_struct *t, int cpu)
{
unsigned long flags;
- write_seqlock_irqsave(&t->vtime_seqlock, flags);
+ raw_spin_lock_irqsave(&t->vtime_lock, flags);
+ write_seqcount_begin(&t->vtime_seq);
t->vtime_snap_whence = VTIME_SYS;
t->vtime_snap = sched_clock_cpu(cpu);
- write_sequnlock_irqrestore(&t->vtime_seqlock, flags);
+ write_seqcount_end(&t->vtime_seq);
+ raw_spin_unlock_irqrestore(&t->vtime_lock, flags);
}
cputime_t task_gtime(struct task_struct *t)
@@ -748,13 +766,13 @@ cputime_t task_gtime(struct task_struct *t)
cputime_t gtime;
do {
- seq = read_seqbegin(&t->vtime_seqlock);
+ seq = read_seqcount_begin(&t->vtime_seq);
gtime = t->gtime;
if (t->flags & PF_VCPU)
gtime += vtime_delta(t);
- } while (read_seqretry(&t->vtime_seqlock, seq));
+ } while (read_seqcount_retry(&t->vtime_seq, seq));
return gtime;
}
@@ -777,7 +795,7 @@ fetch_task_cputime(struct task_struct *t,
*udelta = 0;
*sdelta = 0;
- seq = read_seqbegin(&t->vtime_seqlock);
+ seq = read_seqcount_begin(&t->vtime_seq);
if (u_dst)
*u_dst = *u_src;
@@ -801,7 +819,7 @@ fetch_task_cputime(struct task_struct *t,
if (t->vtime_snap_whence == VTIME_SYS)
*sdelta = delta;
}
- } while (read_seqretry(&t->vtime_seqlock, seq));
+ } while (read_seqcount_retry(&t->vtime_seq, seq));
}
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index fd9ca1d..70812af 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -256,6 +256,9 @@ void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
P(rt_throttled);
PN(rt_time);
PN(rt_runtime);
+#ifdef CONFIG_SMP
+ P(rt_nr_migratory);
+#endif
#undef PN
#undef P
@@ -585,6 +588,10 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
#endif
P(policy);
P(prio);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ P(migrate_disable);
+#endif
+ P(nr_cpus_allowed);
#undef PN
#undef __PN
#undef P
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 790e2fc..0af1448 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1902,7 +1902,7 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
ideal_runtime = sched_slice(cfs_rq, curr);
delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
if (delta_exec > ideal_runtime) {
- resched_task(rq_of(cfs_rq)->curr);
+ resched_task_lazy(rq_of(cfs_rq)->curr);
/*
* The current task ran long enough, ensure it doesn't get
* re-elected due to buddy favours.
@@ -1926,7 +1926,7 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
return;
if (delta > ideal_runtime)
- resched_task(rq_of(cfs_rq)->curr);
+ resched_task_lazy(rq_of(cfs_rq)->curr);
}
static void
@@ -2047,7 +2047,7 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
* validating it and just reschedule.
*/
if (queued) {
- resched_task(rq_of(cfs_rq)->curr);
+ resched_task_lazy(rq_of(cfs_rq)->curr);
return;
}
/*
@@ -2237,7 +2237,7 @@ static void __account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
* hierarchy can be throttled
*/
if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
- resched_task(rq_of(cfs_rq)->curr);
+ resched_task_lazy(rq_of(cfs_rq)->curr);
}
static __always_inline
@@ -2837,7 +2837,7 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
if (delta < 0) {
if (rq->curr == p)
- resched_task(p);
+ resched_task_lazy(p);
return;
}
@@ -3704,7 +3704,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
return;
preempt:
- resched_task(curr);
+ resched_task_lazy(curr);
/*
* Only set the backward buddy when the current task is still
* on the rq. This can happen when a wakeup gets interleaved
@@ -5979,7 +5979,7 @@ static void task_fork_fair(struct task_struct *p)
* 'current' within the tree based on its new key value.
*/
swap(curr->vruntime, se->vruntime);
- resched_task(rq->curr);
+ resched_task_lazy(rq->curr);
}
se->vruntime -= cfs_rq->min_vruntime;
@@ -6004,7 +6004,7 @@ prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio)
*/
if (rq->curr == p) {
if (p->prio > oldprio)
- resched_task(rq->curr);
+ resched_task_lazy(rq->curr);
} else
check_preempt_curr(rq, p, 0);
}
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 99399f8..4594051 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -50,11 +50,18 @@ SCHED_FEAT(LB_BIAS, true)
*/
SCHED_FEAT(NONTASK_POWER, true)
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Queue remote wakeups on the target CPU and process them
* using the scheduler IPI. Reduces rq->lock contention/bounces.
*/
SCHED_FEAT(TTWU_QUEUE, true)
+#else
+SCHED_FEAT(TTWU_QUEUE, false)
+# ifdef CONFIG_PREEMPT_LAZY
+SCHED_FEAT(PREEMPT_LAZY, true)
+# endif
+#endif
SCHED_FEAT(FORCE_SD_OVERLAP, false)
SCHED_FEAT(RT_RUNTIME_SHARE, true)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index ff04e1a..240fc60 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -43,6 +43,7 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
hrtimer_init(&rt_b->rt_period_timer,
CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ rt_b->rt_period_timer.irqsafe = 1;
rt_b->rt_period_timer.function = sched_rt_period_timer;
}
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 4f31059..2843303 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -898,6 +898,7 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
#define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
#define WF_FORK 0x02 /* child wakeup after fork */
#define WF_MIGRATED 0x4 /* internal use, task got migrated */
+#define WF_LOCK_SLEEPER 0x08 /* wakeup spinlock "sleeper" */
/*
* To aid in avoiding the subversion of "niceness" due to uneven distribution
@@ -1045,6 +1046,15 @@ extern void init_sched_fair_class(void);
extern void resched_task(struct task_struct *p);
extern void resched_cpu(int cpu);
+#ifdef CONFIG_PREEMPT_LAZY
+extern void resched_task_lazy(struct task_struct *tsk);
+#else
+static inline void resched_task_lazy(struct task_struct *tsk)
+{
+ resched_task(tsk);
+}
+#endif
+
extern struct rt_bandwidth def_rt_bandwidth;
extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
diff --git a/kernel/signal.c b/kernel/signal.c
index ded28b9..3d32f54 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -14,6 +14,7 @@
#include <linux/export.h>
#include <linux/init.h>
#include <linux/sched.h>
+#include <linux/sched/rt.h>
#include <linux/fs.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
@@ -349,13 +350,45 @@ static bool task_participate_group_stop(struct task_struct *task)
return false;
}
+#ifdef __HAVE_ARCH_CMPXCHG
+static inline struct sigqueue *get_task_cache(struct task_struct *t)
+{
+ struct sigqueue *q = t->sigqueue_cache;
+
+ if (cmpxchg(&t->sigqueue_cache, q, NULL) != q)
+ return NULL;
+ return q;
+}
+
+static inline int put_task_cache(struct task_struct *t, struct sigqueue *q)
+{
+ if (cmpxchg(&t->sigqueue_cache, NULL, q) == NULL)
+ return 0;
+ return 1;
+}
+
+#else
+
+static inline struct sigqueue *get_task_cache(struct task_struct *t)
+{
+ return NULL;
+}
+
+static inline int put_task_cache(struct task_struct *t, struct sigqueue *q)
+{
+ return 1;
+}
+
+#endif
+
/*
* allocate a new signal queue record
* - this may be called without locks if and only if t == current, otherwise an
* appropriate lock must be held to stop the target task from exiting
*/
static struct sigqueue *
-__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit)
+__sigqueue_do_alloc(int sig, struct task_struct *t, gfp_t flags,
+ int override_rlimit, int fromslab)
{
struct sigqueue *q = NULL;
struct user_struct *user;
@@ -372,7 +405,10 @@ __sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimi
if (override_rlimit ||
atomic_read(&user->sigpending) <=
task_rlimit(t, RLIMIT_SIGPENDING)) {
- q = kmem_cache_alloc(sigqueue_cachep, flags);
+ if (!fromslab)
+ q = get_task_cache(t);
+ if (!q)
+ q = kmem_cache_alloc(sigqueue_cachep, flags);
} else {
print_dropped_signal(sig);
}
@@ -389,6 +425,13 @@ __sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimi
return q;
}
+static struct sigqueue *
+__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags,
+ int override_rlimit)
+{
+ return __sigqueue_do_alloc(sig, t, flags, override_rlimit, 0);
+}
+
static void __sigqueue_free(struct sigqueue *q)
{
if (q->flags & SIGQUEUE_PREALLOC)
@@ -398,6 +441,21 @@ static void __sigqueue_free(struct sigqueue *q)
kmem_cache_free(sigqueue_cachep, q);
}
+static void sigqueue_free_current(struct sigqueue *q)
+{
+ struct user_struct *up;
+
+ if (q->flags & SIGQUEUE_PREALLOC)
+ return;
+
+ up = q->user;
+ if (rt_prio(current->normal_prio) && !put_task_cache(current, q)) {
+ atomic_dec(&up->sigpending);
+ free_uid(up);
+ } else
+ __sigqueue_free(q);
+}
+
void flush_sigqueue(struct sigpending *queue)
{
struct sigqueue *q;
@@ -411,6 +469,21 @@ void flush_sigqueue(struct sigpending *queue)
}
/*
+ * Called from __exit_signal. Flush tsk->pending and
+ * tsk->sigqueue_cache
+ */
+void flush_task_sigqueue(struct task_struct *tsk)
+{
+ struct sigqueue *q;
+
+ flush_sigqueue(&tsk->pending);
+
+ q = get_task_cache(tsk);
+ if (q)
+ kmem_cache_free(sigqueue_cachep, q);
+}
+
+/*
* Flush all pending signals for a task.
*/
void __flush_signals(struct task_struct *t)
@@ -562,7 +635,7 @@ static void collect_signal(int sig, struct sigpending *list, siginfo_t *info)
still_pending:
list_del_init(&first->list);
copy_siginfo(info, &first->info);
- __sigqueue_free(first);
+ sigqueue_free_current(first);
} else {
/*
* Ok, it wasn't in the queue. This must be
@@ -608,6 +681,8 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
{
int signr;
+ WARN_ON_ONCE(tsk != current);
+
/* We only dequeue private signals from ourselves, we don't let
* signalfd steal them
*/
@@ -1230,8 +1305,8 @@ int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p,
* We don't want to have recursive SIGSEGV's etc, for example,
* that is why we also clear SIGNAL_UNKILLABLE.
*/
-int
-force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+static int
+do_force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
{
unsigned long int flags;
int ret, blocked, ignored;
@@ -1256,6 +1331,39 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
return ret;
}
+int force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+{
+/*
+ * On some archs, PREEMPT_RT has to delay sending a signal from a trap
+ * since it can not enable preemption, and the signal code's spin_locks
+ * turn into mutexes. Instead, it must set TIF_NOTIFY_RESUME which will
+ * send the signal on exit of the trap.
+ */
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+ if (in_atomic()) {
+ if (WARN_ON_ONCE(t != current))
+ return 0;
+ if (WARN_ON_ONCE(t->forced_info.si_signo))
+ return 0;
+
+ if (is_si_special(info)) {
+ WARN_ON_ONCE(info != SEND_SIG_PRIV);
+ t->forced_info.si_signo = sig;
+ t->forced_info.si_errno = 0;
+ t->forced_info.si_code = SI_KERNEL;
+ t->forced_info.si_pid = 0;
+ t->forced_info.si_uid = 0;
+ } else {
+ t->forced_info = *info;
+ }
+
+ set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+ return 0;
+ }
+#endif
+ return do_force_sig_info(sig, info, t);
+}
+
/*
* Nuke all other threads in the group.
*/
@@ -1286,12 +1394,12 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
struct sighand_struct *sighand;
for (;;) {
- local_irq_save(*flags);
+ local_irq_save_nort(*flags);
rcu_read_lock();
sighand = rcu_dereference(tsk->sighand);
if (unlikely(sighand == NULL)) {
rcu_read_unlock();
- local_irq_restore(*flags);
+ local_irq_restore_nort(*flags);
break;
}
@@ -1302,7 +1410,7 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
}
spin_unlock(&sighand->siglock);
rcu_read_unlock();
- local_irq_restore(*flags);
+ local_irq_restore_nort(*flags);
}
return sighand;
@@ -1547,7 +1655,8 @@ EXPORT_SYMBOL(kill_pid);
*/
struct sigqueue *sigqueue_alloc(void)
{
- struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0);
+ /* Preallocated sigqueue objects always from the slabcache ! */
+ struct sigqueue *q = __sigqueue_do_alloc(-1, current, GFP_KERNEL, 0, 1);
if (q)
q->flags |= SIGQUEUE_PREALLOC;
@@ -1908,15 +2017,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info)
if (gstop_done && ptrace_reparented(current))
do_notify_parent_cldstop(current, false, why);
- /*
- * Don't want to allow preemption here, because
- * sys_ptrace() needs this task to be inactive.
- *
- * XXX: implement read_unlock_no_resched().
- */
- preempt_disable();
read_unlock(&tasklist_lock);
- preempt_enable_no_resched();
freezable_schedule();
} else {
/*
diff --git a/kernel/softirq.c b/kernel/softirq.c
index d7d498d..15ad603 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -21,10 +21,12 @@
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/rcupdate.h>
+#include <linux/delay.h>
#include <linux/ftrace.h>
#include <linux/smp.h>
#include <linux/smpboot.h>
#include <linux/tick.h>
+#include <linux/locallock.h>
#define CREATE_TRACE_POINTS
#include <trace/events/irq.h>
@@ -62,6 +64,98 @@ char *softirq_to_name[NR_SOFTIRQS] = {
"TASKLET", "SCHED", "HRTIMER", "RCU"
};
+#ifdef CONFIG_NO_HZ_COMMON
+# ifdef CONFIG_PREEMPT_RT_FULL
+
+struct softirq_runner {
+ struct task_struct *runner[NR_SOFTIRQS];
+};
+
+static DEFINE_PER_CPU(struct softirq_runner, softirq_runners);
+
+static inline void softirq_set_runner(unsigned int sirq)
+{
+ struct softirq_runner *sr = &__get_cpu_var(softirq_runners);
+
+ sr->runner[sirq] = current;
+}
+
+static inline void softirq_clr_runner(unsigned int sirq)
+{
+ struct softirq_runner *sr = &__get_cpu_var(softirq_runners);
+
+ sr->runner[sirq] = NULL;
+}
+
+/*
+ * On preempt-rt a softirq running context might be blocked on a
+ * lock. There might be no other runnable task on this CPU because the
+ * lock owner runs on some other CPU. So we have to go into idle with
+ * the pending bit set. Therefor we need to check this otherwise we
+ * warn about false positives which confuses users and defeats the
+ * whole purpose of this test.
+ *
+ * This code is called with interrupts disabled.
+ */
+void softirq_check_pending_idle(void)
+{
+ static int rate_limit;
+ struct softirq_runner *sr = &__get_cpu_var(softirq_runners);
+ u32 warnpending;
+ int i;
+
+ if (rate_limit >= 10)
+ return;
+
+ warnpending = local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK;
+ for (i = 0; i < NR_SOFTIRQS; i++) {
+ struct task_struct *tsk = sr->runner[i];
+
+ /*
+ * The wakeup code in rtmutex.c wakes up the task
+ * _before_ it sets pi_blocked_on to NULL under
+ * tsk->pi_lock. So we need to check for both: state
+ * and pi_blocked_on.
+ */
+ if (tsk) {
+ raw_spin_lock(&tsk->pi_lock);
+ if (tsk->pi_blocked_on || tsk->state == TASK_RUNNING) {
+ /* Clear all bits pending in that task */
+ warnpending &= ~(tsk->softirqs_raised);
+ warnpending &= ~(1 << i);
+ }
+ raw_spin_unlock(&tsk->pi_lock);
+ }
+ }
+
+ if (warnpending) {
+ printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+ warnpending);
+ rate_limit++;
+ }
+}
+# else
+/*
+ * On !PREEMPT_RT we just printk rate limited:
+ */
+void softirq_check_pending_idle(void)
+{
+ static int rate_limit;
+
+ if (rate_limit < 10 &&
+ (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
+ printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+ local_softirq_pending());
+ rate_limit++;
+ }
+}
+# endif
+
+#else /* !CONFIG_NO_HZ_COMMON */
+static inline void softirq_set_runner(unsigned int sirq) { }
+static inline void softirq_clr_runner(unsigned int sirq) { }
+#endif
+
/*
* we cannot loop indefinitely here to avoid userspace starvation,
* but we also don't want to introduce a worst case 1/HZ latency
@@ -77,6 +171,57 @@ static void wakeup_softirqd(void)
wake_up_process(tsk);
}
+static void handle_softirq(unsigned int vec_nr, int cpu, int need_rcu_bh_qs)
+{
+ struct softirq_action *h = softirq_vec + vec_nr;
+ unsigned int prev_count = preempt_count();
+
+ kstat_incr_softirqs_this_cpu(vec_nr);
+ trace_softirq_entry(vec_nr);
+ h->action(h);
+ trace_softirq_exit(vec_nr);
+
+ if (unlikely(prev_count != preempt_count())) {
+ pr_err("softirq %u %s %p preempt count leak: %08x -> %08x\n",
+ vec_nr, softirq_to_name[vec_nr], h->action,
+ prev_count, (unsigned int) preempt_count());
+ preempt_count() = prev_count;
+ }
+ if (need_rcu_bh_qs)
+ rcu_bh_qs(cpu);
+}
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+static inline int ksoftirqd_softirq_pending(void)
+{
+ return local_softirq_pending();
+}
+
+static void handle_pending_softirqs(u32 pending, int cpu, int need_rcu_bh_qs)
+{
+ unsigned int vec_nr;
+
+ local_irq_enable();
+ for (vec_nr = 0; pending; vec_nr++, pending >>= 1) {
+ if (pending & 1)
+ handle_softirq(vec_nr, cpu, need_rcu_bh_qs);
+ }
+ local_irq_disable();
+}
+
+static void run_ksoftirqd(unsigned int cpu)
+{
+ local_irq_disable();
+ if (ksoftirqd_softirq_pending()) {
+ __do_softirq();
+ rcu_note_context_switch(cpu);
+ local_irq_enable();
+ cond_resched();
+ return;
+ }
+ local_irq_enable();
+}
+
/*
* preempt_count and SOFTIRQ_OFFSET usage:
* - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving
@@ -209,14 +354,51 @@ EXPORT_SYMBOL(local_bh_enable_ip);
#define MAX_SOFTIRQ_TIME msecs_to_jiffies(2)
#define MAX_SOFTIRQ_RESTART 10
+#ifdef CONFIG_TRACE_IRQFLAGS
+/*
+ * Convoluted means of passing __do_softirq() a message through the various
+ * architecture execute_on_stack() bits.
+ *
+ * When we run softirqs from irq_exit() and thus on the hardirq stack we need
+ * to keep the lockdep irq context tracking as tight as possible in order to
+ * not miss-qualify lock contexts and miss possible deadlocks.
+ */
+static DEFINE_PER_CPU(int, softirq_from_hardirq);
+
+static inline void lockdep_softirq_from_hardirq(void)
+{
+ this_cpu_write(softirq_from_hardirq, 1);
+}
+
+static inline void lockdep_softirq_start(void)
+{
+ if (this_cpu_read(softirq_from_hardirq))
+ trace_hardirq_exit();
+ lockdep_softirq_enter();
+}
+
+static inline void lockdep_softirq_end(void)
+{
+ lockdep_softirq_exit();
+ if (this_cpu_read(softirq_from_hardirq)) {
+ this_cpu_write(softirq_from_hardirq, 0);
+ trace_hardirq_enter();
+ }
+}
+
+#else
+static inline void lockdep_softirq_from_hardirq(void) { }
+static inline void lockdep_softirq_start(void) { }
+static inline void lockdep_softirq_end(void) { }
+#endif
+
asmlinkage void __do_softirq(void)
{
- struct softirq_action *h;
- __u32 pending;
unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
- int cpu;
unsigned long old_flags = current->flags;
int max_restart = MAX_SOFTIRQ_RESTART;
+ __u32 pending;
+ int cpu;
/*
* Mask out PF_MEMALLOC s current task context is borrowed for the
@@ -229,43 +411,14 @@ asmlinkage void __do_softirq(void)
account_irq_enter_time(current);
__local_bh_disable(_RET_IP_, SOFTIRQ_OFFSET);
- lockdep_softirq_enter();
+ lockdep_softirq_start();
cpu = smp_processor_id();
restart:
/* Reset the pending bitmask before enabling irqs */
set_softirq_pending(0);
- local_irq_enable();
-
- h = softirq_vec;
-
- do {
- if (pending & 1) {
- unsigned int vec_nr = h - softirq_vec;
- int prev_count = preempt_count();
-
- kstat_incr_softirqs_this_cpu(vec_nr);
-
- trace_softirq_entry(vec_nr);
- h->action(h);
- trace_softirq_exit(vec_nr);
- if (unlikely(prev_count != preempt_count())) {
- printk(KERN_ERR "huh, entered softirq %u %s %p"
- "with preempt_count %08x,"
- " exited with %08x?\n", vec_nr,
- softirq_to_name[vec_nr], h->action,
- prev_count, preempt_count());
- preempt_count() = prev_count;
- }
-
- rcu_bh_qs(cpu);
- }
- h++;
- pending >>= 1;
- } while (pending);
-
- local_irq_disable();
+ handle_pending_softirqs(pending, cpu, 1);
pending = local_softirq_pending();
if (pending) {
@@ -276,8 +429,7 @@ restart:
wakeup_softirqd();
}
- lockdep_softirq_exit();
-
+ lockdep_softirq_end();
account_irq_exit_time(current);
__local_bh_enable(SOFTIRQ_OFFSET);
tsk_restore_flags(current, old_flags, PF_MEMALLOC);
@@ -306,6 +458,261 @@ asmlinkage void do_softirq(void)
#endif
/*
+ * This function must run with irqs disabled!
+ */
+void raise_softirq_irqoff(unsigned int nr)
+{
+ __raise_softirq_irqoff(nr);
+
+ /*
+ * If we're in an interrupt or softirq, we're done
+ * (this also catches softirq-disabled code). We will
+ * actually run the softirq once we return from
+ * the irq or softirq.
+ *
+ * Otherwise we wake up ksoftirqd to make sure we
+ * schedule the softirq soon.
+ */
+ if (!in_interrupt())
+ wakeup_softirqd();
+}
+
+void __raise_softirq_irqoff(unsigned int nr)
+{
+ trace_softirq_raise(nr);
+ or_softirq_pending(1UL << nr);
+}
+
+static inline void local_bh_disable_nort(void) { local_bh_disable(); }
+static inline void _local_bh_enable_nort(void) { _local_bh_enable(); }
+static void ksoftirqd_set_sched_params(unsigned int cpu) { }
+static void ksoftirqd_clr_sched_params(unsigned int cpu, bool online) { }
+
+#else /* !PREEMPT_RT_FULL */
+
+/*
+ * On RT we serialize softirq execution with a cpu local lock per softirq
+ */
+static DEFINE_PER_CPU(struct local_irq_lock [NR_SOFTIRQS], local_softirq_locks);
+
+void __init softirq_early_init(void)
+{
+ int i;
+
+ for (i = 0; i < NR_SOFTIRQS; i++)
+ local_irq_lock_init(local_softirq_locks[i]);
+}
+
+static void lock_softirq(int which)
+{
+ local_lock(local_softirq_locks[which]);
+}
+
+static void unlock_softirq(int which)
+{
+ local_unlock(local_softirq_locks[which]);
+}
+
+static void do_single_softirq(int which, int need_rcu_bh_qs)
+{
+ unsigned long old_flags = current->flags;
+
+ current->flags &= ~PF_MEMALLOC;
+ vtime_account_irq_enter(current);
+ current->flags |= PF_IN_SOFTIRQ;
+ lockdep_softirq_enter();
+ local_irq_enable();
+ handle_softirq(which, smp_processor_id(), need_rcu_bh_qs);
+ local_irq_disable();
+ lockdep_softirq_exit();
+ current->flags &= ~PF_IN_SOFTIRQ;
+ vtime_account_irq_enter(current);
+ tsk_restore_flags(current, old_flags, PF_MEMALLOC);
+}
+
+/*
+ * Called with interrupts disabled. Process softirqs which were raised
+ * in current context (or on behalf of ksoftirqd).
+ */
+static void do_current_softirqs(int need_rcu_bh_qs)
+{
+ while (current->softirqs_raised) {
+ int i = __ffs(current->softirqs_raised);
+ unsigned int pending, mask = (1U << i);
+
+ current->softirqs_raised &= ~mask;
+ local_irq_enable();
+
+ /*
+ * If the lock is contended, we boost the owner to
+ * process the softirq or leave the critical section
+ * now.
+ */
+ lock_softirq(i);
+ local_irq_disable();
+ softirq_set_runner(i);
+ /*
+ * Check with the local_softirq_pending() bits,
+ * whether we need to process this still or if someone
+ * else took care of it.
+ */
+ pending = local_softirq_pending();
+ if (pending & mask) {
+ set_softirq_pending(pending & ~mask);
+ do_single_softirq(i, need_rcu_bh_qs);
+ }
+ softirq_clr_runner(i);
+ unlock_softirq(i);
+ WARN_ON(current->softirq_nestcnt != 1);
+ }
+}
+
+void local_bh_disable(void)
+{
+ if (++current->softirq_nestcnt == 1)
+ migrate_disable();
+}
+EXPORT_SYMBOL(local_bh_disable);
+
+void local_bh_enable(void)
+{
+ if (WARN_ON(current->softirq_nestcnt == 0))
+ return;
+
+ local_irq_disable();
+ if (current->softirq_nestcnt == 1 && current->softirqs_raised)
+ do_current_softirqs(1);
+ local_irq_enable();
+
+ if (--current->softirq_nestcnt == 0)
+ migrate_enable();
+}
+EXPORT_SYMBOL(local_bh_enable);
+
+void local_bh_enable_ip(unsigned long ip)
+{
+ local_bh_enable();
+}
+EXPORT_SYMBOL(local_bh_enable_ip);
+
+void _local_bh_enable(void)
+{
+ if (WARN_ON(current->softirq_nestcnt == 0))
+ return;
+ if (--current->softirq_nestcnt == 0)
+ migrate_enable();
+}
+EXPORT_SYMBOL(_local_bh_enable);
+
+int in_serving_softirq(void)
+{
+ return current->flags & PF_IN_SOFTIRQ;
+}
+EXPORT_SYMBOL(in_serving_softirq);
+
+/* Called with preemption disabled */
+static void run_ksoftirqd(unsigned int cpu)
+{
+ local_irq_disable();
+ current->softirq_nestcnt++;
+ do_current_softirqs(1);
+ current->softirq_nestcnt--;
+ rcu_note_context_switch(cpu);
+ local_irq_enable();
+}
+
+/*
+ * Called from netif_rx_ni(). Preemption enabled, but migration
+ * disabled. So the cpu can't go away under us.
+ */
+void thread_do_softirq(void)
+{
+ if (!in_serving_softirq() && current->softirqs_raised) {
+ current->softirq_nestcnt++;
+ do_current_softirqs(0);
+ current->softirq_nestcnt--;
+ }
+}
+
+static void do_raise_softirq_irqoff(unsigned int nr)
+{
+ trace_softirq_raise(nr);
+ or_softirq_pending(1UL << nr);
+
+ /*
+ * If we are not in a hard interrupt and inside a bh disabled
+ * region, we simply raise the flag on current. local_bh_enable()
+ * will make sure that the softirq is executed. Otherwise we
+ * delegate it to ksoftirqd.
+ */
+ if (!in_irq() && current->softirq_nestcnt)
+ current->softirqs_raised |= (1U << nr);
+ else if (__this_cpu_read(ksoftirqd))
+ __this_cpu_read(ksoftirqd)->softirqs_raised |= (1U << nr);
+}
+
+void __raise_softirq_irqoff(unsigned int nr)
+{
+ do_raise_softirq_irqoff(nr);
+ if (!in_irq() && !current->softirq_nestcnt)
+ wakeup_softirqd();
+}
+
+/*
+ * This function must run with irqs disabled!
+ */
+void raise_softirq_irqoff(unsigned int nr)
+{
+ do_raise_softirq_irqoff(nr);
+
+ /*
+ * If we're in an hard interrupt we let irq return code deal
+ * with the wakeup of ksoftirqd.
+ */
+ if (in_irq())
+ return;
+
+ /*
+ * If we are in thread context but outside of a bh disabled
+ * region, we need to wake ksoftirqd as well.
+ *
+ * CHECKME: Some of the places which do that could be wrapped
+ * into local_bh_disable/enable pairs. Though it's unclear
+ * whether this is worth the effort. To find those places just
+ * raise a WARN() if the condition is met.
+ */
+ if (!current->softirq_nestcnt)
+ wakeup_softirqd();
+}
+
+static inline int ksoftirqd_softirq_pending(void)
+{
+ return current->softirqs_raised;
+}
+
+static inline void local_bh_disable_nort(void) { }
+static inline void _local_bh_enable_nort(void) { }
+
+static inline void ksoftirqd_set_sched_params(unsigned int cpu)
+{
+ struct sched_param param = { .sched_priority = 1 };
+
+ sched_setscheduler(current, SCHED_FIFO, &param);
+ /* Take over all pending softirqs when starting */
+ local_irq_disable();
+ current->softirqs_raised = local_softirq_pending();
+ local_irq_enable();
+}
+
+static inline void ksoftirqd_clr_sched_params(unsigned int cpu, bool online)
+{
+ struct sched_param param = { .sched_priority = 0 };
+
+ sched_setscheduler(current, SCHED_NORMAL, &param);
+}
+
+#endif /* PREEMPT_RT_FULL */
+/*
* Enter an interrupt context.
*/
void irq_enter(void)
@@ -318,9 +725,9 @@ void irq_enter(void)
* Prevent raise_softirq from needlessly waking up ksoftirqd
* here, as softirq will be serviced on return from interrupt.
*/
- local_bh_disable();
+ local_bh_disable_nort();
tick_check_idle(cpu);
- _local_bh_enable();
+ _local_bh_enable_nort();
}
__irq_enter();
@@ -328,7 +735,9 @@ void irq_enter(void)
static inline void invoke_softirq(void)
{
+#ifndef CONFIG_PREEMPT_RT_FULL
if (!force_irqthreads) {
+ lockdep_softirq_from_hardirq();
/*
* We can safely execute softirq on the current stack if
* it is the irq stack, because it should be near empty
@@ -341,6 +750,15 @@ static inline void invoke_softirq(void)
} else {
wakeup_softirqd();
}
+#else /* PREEMPT_RT_FULL */
+ unsigned long flags;
+
+ local_irq_save(flags);
+ if (__this_cpu_read(ksoftirqd) &&
+ __this_cpu_read(ksoftirqd)->softirqs_raised)
+ wakeup_softirqd();
+ local_irq_restore(flags);
+#endif
}
static inline void tick_irq_exit(void)
@@ -368,33 +786,13 @@ void irq_exit(void)
#endif
account_irq_exit_time(current);
- trace_hardirq_exit();
sub_preempt_count(HARDIRQ_OFFSET);
if (!in_interrupt() && local_softirq_pending())
invoke_softirq();
tick_irq_exit();
rcu_irq_exit();
-}
-
-/*
- * This function must run with irqs disabled!
- */
-inline void raise_softirq_irqoff(unsigned int nr)
-{
- __raise_softirq_irqoff(nr);
-
- /*
- * If we're in an interrupt or softirq, we're done
- * (this also catches softirq-disabled code). We will
- * actually run the softirq once we return from
- * the irq or softirq.
- *
- * Otherwise we wake up ksoftirqd to make sure we
- * schedule the softirq soon.
- */
- if (!in_interrupt())
- wakeup_softirqd();
+ trace_hardirq_exit(); /* must be last! */
}
void raise_softirq(unsigned int nr)
@@ -406,12 +804,6 @@ void raise_softirq(unsigned int nr)
local_irq_restore(flags);
}
-void __raise_softirq_irqoff(unsigned int nr)
-{
- trace_softirq_raise(nr);
- or_softirq_pending(1UL << nr);
-}
-
void open_softirq(int nr, void (*action)(struct softirq_action *))
{
softirq_vec[nr].action = action;
@@ -429,15 +821,45 @@ struct tasklet_head
static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec);
static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec);
+static void inline
+__tasklet_common_schedule(struct tasklet_struct *t, struct tasklet_head *head, unsigned int nr)
+{
+ if (tasklet_trylock(t)) {
+again:
+ /* We may have been preempted before tasklet_trylock
+ * and __tasklet_action may have already run.
+ * So double check the sched bit while the takslet
+ * is locked before adding it to the list.
+ */
+ if (test_bit(TASKLET_STATE_SCHED, &t->state)) {
+ t->next = NULL;
+ *head->tail = t;
+ head->tail = &(t->next);
+ raise_softirq_irqoff(nr);
+ tasklet_unlock(t);
+ } else {
+ /* This is subtle. If we hit the corner case above
+ * It is possible that we get preempted right here,
+ * and another task has successfully called
+ * tasklet_schedule(), then this function, and
+ * failed on the trylock. Thus we must be sure
+ * before releasing the tasklet lock, that the
+ * SCHED_BIT is clear. Otherwise the tasklet
+ * may get its SCHED_BIT set, but not added to the
+ * list
+ */
+ if (!tasklet_tryunlock(t))
+ goto again;
+ }
+ }
+}
+
void __tasklet_schedule(struct tasklet_struct *t)
{
unsigned long flags;
local_irq_save(flags);
- t->next = NULL;
- *__this_cpu_read(tasklet_vec.tail) = t;
- __this_cpu_write(tasklet_vec.tail, &(t->next));
- raise_softirq_irqoff(TASKLET_SOFTIRQ);
+ __tasklet_common_schedule(t, &__get_cpu_var(tasklet_vec), TASKLET_SOFTIRQ);
local_irq_restore(flags);
}
@@ -448,10 +870,7 @@ void __tasklet_hi_schedule(struct tasklet_struct *t)
unsigned long flags;
local_irq_save(flags);
- t->next = NULL;
- *__this_cpu_read(tasklet_hi_vec.tail) = t;
- __this_cpu_write(tasklet_hi_vec.tail, &(t->next));
- raise_softirq_irqoff(HI_SOFTIRQ);
+ __tasklet_common_schedule(t, &__get_cpu_var(tasklet_hi_vec), HI_SOFTIRQ);
local_irq_restore(flags);
}
@@ -459,50 +878,119 @@ EXPORT_SYMBOL(__tasklet_hi_schedule);
void __tasklet_hi_schedule_first(struct tasklet_struct *t)
{
- BUG_ON(!irqs_disabled());
-
- t->next = __this_cpu_read(tasklet_hi_vec.head);
- __this_cpu_write(tasklet_hi_vec.head, t);
- __raise_softirq_irqoff(HI_SOFTIRQ);
+ __tasklet_hi_schedule(t);
}
EXPORT_SYMBOL(__tasklet_hi_schedule_first);
-static void tasklet_action(struct softirq_action *a)
+void tasklet_enable(struct tasklet_struct *t)
{
- struct tasklet_struct *list;
+ if (!atomic_dec_and_test(&t->count))
+ return;
+ if (test_and_clear_bit(TASKLET_STATE_PENDING, &t->state))
+ tasklet_schedule(t);
+}
- local_irq_disable();
- list = __this_cpu_read(tasklet_vec.head);
- __this_cpu_write(tasklet_vec.head, NULL);
- __this_cpu_write(tasklet_vec.tail, &__get_cpu_var(tasklet_vec).head);
- local_irq_enable();
+EXPORT_SYMBOL(tasklet_enable);
+
+void tasklet_hi_enable(struct tasklet_struct *t)
+{
+ if (!atomic_dec_and_test(&t->count))
+ return;
+ if (test_and_clear_bit(TASKLET_STATE_PENDING, &t->state))
+ tasklet_hi_schedule(t);
+}
+
+EXPORT_SYMBOL(tasklet_hi_enable);
+
+static void
+__tasklet_action(struct softirq_action *a, struct tasklet_struct *list)
+{
+ int loops = 1000000;
while (list) {
struct tasklet_struct *t = list;
list = list->next;
- if (tasklet_trylock(t)) {
- if (!atomic_read(&t->count)) {
- if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
- BUG();
- t->func(t->data);
- tasklet_unlock(t);
- continue;
- }
- tasklet_unlock(t);
+ /*
+ * Should always succeed - after a tasklist got on the
+ * list (after getting the SCHED bit set from 0 to 1),
+ * nothing but the tasklet softirq it got queued to can
+ * lock it:
+ */
+ if (!tasklet_trylock(t)) {
+ WARN_ON(1);
+ continue;
}
- local_irq_disable();
t->next = NULL;
- *__this_cpu_read(tasklet_vec.tail) = t;
- __this_cpu_write(tasklet_vec.tail, &(t->next));
- __raise_softirq_irqoff(TASKLET_SOFTIRQ);
- local_irq_enable();
+
+ /*
+ * If we cannot handle the tasklet because it's disabled,
+ * mark it as pending. tasklet_enable() will later
+ * re-schedule the tasklet.
+ */
+ if (unlikely(atomic_read(&t->count))) {
+out_disabled:
+ /* implicit unlock: */
+ wmb();
+ t->state = TASKLET_STATEF_PENDING;
+ continue;
+ }
+
+ /*
+ * After this point on the tasklet might be rescheduled
+ * on another CPU, but it can only be added to another
+ * CPU's tasklet list if we unlock the tasklet (which we
+ * dont do yet).
+ */
+ if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+ WARN_ON(1);
+
+again:
+ t->func(t->data);
+
+ /*
+ * Try to unlock the tasklet. We must use cmpxchg, because
+ * another CPU might have scheduled or disabled the tasklet.
+ * We only allow the STATE_RUN -> 0 transition here.
+ */
+ while (!tasklet_tryunlock(t)) {
+ /*
+ * If it got disabled meanwhile, bail out:
+ */
+ if (atomic_read(&t->count))
+ goto out_disabled;
+ /*
+ * If it got scheduled meanwhile, re-execute
+ * the tasklet function:
+ */
+ if (test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+ goto again;
+ if (!--loops) {
+ printk("hm, tasklet state: %08lx\n", t->state);
+ WARN_ON(1);
+ tasklet_unlock(t);
+ break;
+ }
+ }
}
}
+static void tasklet_action(struct softirq_action *a)
+{
+ struct tasklet_struct *list;
+
+ local_irq_disable();
+ list = __get_cpu_var(tasklet_vec).head;
+ __get_cpu_var(tasklet_vec).head = NULL;
+ __get_cpu_var(tasklet_vec).tail = &__get_cpu_var(tasklet_vec).head;
+ local_irq_enable();
+
+ __tasklet_action(a, list);
+}
+
static void tasklet_hi_action(struct softirq_action *a)
{
struct tasklet_struct *list;
@@ -513,29 +1001,7 @@ static void tasklet_hi_action(struct softirq_action *a)
__this_cpu_write(tasklet_hi_vec.tail, &__get_cpu_var(tasklet_hi_vec).head);
local_irq_enable();
- while (list) {
- struct tasklet_struct *t = list;
-
- list = list->next;
-
- if (tasklet_trylock(t)) {
- if (!atomic_read(&t->count)) {
- if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
- BUG();
- t->func(t->data);
- tasklet_unlock(t);
- continue;
- }
- tasklet_unlock(t);
- }
-
- local_irq_disable();
- t->next = NULL;
- *__this_cpu_read(tasklet_hi_vec.tail) = t;
- __this_cpu_write(tasklet_hi_vec.tail, &(t->next));
- __raise_softirq_irqoff(HI_SOFTIRQ);
- local_irq_enable();
- }
+ __tasklet_action(a, list);
}
@@ -558,7 +1024,7 @@ void tasklet_kill(struct tasklet_struct *t)
while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) {
do {
- yield();
+ msleep(1);
} while (test_bit(TASKLET_STATE_SCHED, &t->state));
}
tasklet_unlock_wait(t);
@@ -762,22 +1228,26 @@ void __init softirq_init(void)
open_softirq(HI_SOFTIRQ, tasklet_hi_action);
}
-static int ksoftirqd_should_run(unsigned int cpu)
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
+void tasklet_unlock_wait(struct tasklet_struct *t)
{
- return local_softirq_pending();
+ while (test_bit(TASKLET_STATE_RUN, &(t)->state)) {
+ /*
+ * Hack for now to avoid this busy-loop:
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+ msleep(1);
+#else
+ barrier();
+#endif
+ }
}
+EXPORT_SYMBOL(tasklet_unlock_wait);
+#endif
-static void run_ksoftirqd(unsigned int cpu)
+static int ksoftirqd_should_run(unsigned int cpu)
{
- local_irq_disable();
- if (local_softirq_pending()) {
- __do_softirq();
- rcu_note_context_switch(cpu);
- local_irq_enable();
- cond_resched();
- return;
- }
- local_irq_enable();
+ return ksoftirqd_softirq_pending();
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -860,6 +1330,8 @@ static struct notifier_block cpu_nfb = {
static struct smp_hotplug_thread softirq_threads = {
.store = &ksoftirqd,
+ .setup = ksoftirqd_set_sched_params,
+ .cleanup = ksoftirqd_clr_sched_params,
.thread_should_run = ksoftirqd_should_run,
.thread_fn = run_ksoftirqd,
.thread_comm = "ksoftirqd/%u",
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index 4b082b5..5c76166 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -124,8 +124,11 @@ void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \
* __[spin|read|write]_lock_bh()
*/
BUILD_LOCK_OPS(spin, raw_spinlock);
+
+#ifndef CONFIG_PREEMPT_RT_FULL
BUILD_LOCK_OPS(read, rwlock);
BUILD_LOCK_OPS(write, rwlock);
+#endif
#endif
@@ -209,6 +212,8 @@ void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock)
EXPORT_SYMBOL(_raw_spin_unlock_bh);
#endif
+#ifndef CONFIG_PREEMPT_RT_FULL
+
#ifndef CONFIG_INLINE_READ_TRYLOCK
int __lockfunc _raw_read_trylock(rwlock_t *lock)
{
@@ -353,6 +358,8 @@ void __lockfunc _raw_write_unlock_bh(rwlock_t *lock)
EXPORT_SYMBOL(_raw_write_unlock_bh);
#endif
+#endif /* !PREEMPT_RT_FULL */
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index c09f295..5f02a3f 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -29,12 +29,12 @@ struct cpu_stop_done {
atomic_t nr_todo; /* nr left to execute */
bool executed; /* actually executed? */
int ret; /* collected return value */
- struct completion completion; /* fired if nr_todo reaches 0 */
+ struct task_struct *waiter; /* woken when nr_todo reaches 0 */
};
/* the actual stopper, one per every possible cpu, enabled on online cpus */
struct cpu_stopper {
- spinlock_t lock;
+ raw_spinlock_t lock;
bool enabled; /* is this stopper enabled? */
struct list_head works; /* list of pending works */
};
@@ -47,7 +47,7 @@ static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo)
{
memset(done, 0, sizeof(*done));
atomic_set(&done->nr_todo, nr_todo);
- init_completion(&done->completion);
+ done->waiter = current;
}
/* signal completion unless @done is NULL */
@@ -56,8 +56,10 @@ static void cpu_stop_signal_done(struct cpu_stop_done *done, bool executed)
if (done) {
if (executed)
done->executed = true;
- if (atomic_dec_and_test(&done->nr_todo))
- complete(&done->completion);
+ if (atomic_dec_and_test(&done->nr_todo)) {
+ wake_up_process(done->waiter);
+ done->waiter = NULL;
+ }
}
}
@@ -69,7 +71,7 @@ static void cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)
unsigned long flags;
- spin_lock_irqsave(&stopper->lock, flags);
+ raw_spin_lock_irqsave(&stopper->lock, flags);
if (stopper->enabled) {
list_add_tail(&work->list, &stopper->works);
@@ -77,7 +79,23 @@ static void cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)
} else
cpu_stop_signal_done(work->done, false);
- spin_unlock_irqrestore(&stopper->lock, flags);
+ raw_spin_unlock_irqrestore(&stopper->lock, flags);
+}
+
+static void wait_for_stop_done(struct cpu_stop_done *done)
+{
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ while (atomic_read(&done->nr_todo)) {
+ schedule();
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ }
+ /*
+ * We need to wait until cpu_stop_signal_done() has cleared
+ * done->waiter.
+ */
+ while (done->waiter)
+ cpu_relax();
+ set_current_state(TASK_RUNNING);
}
/**
@@ -111,7 +129,7 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
cpu_stop_init_done(&done, 1);
cpu_stop_queue_work(cpu, &work);
- wait_for_completion(&done.completion);
+ wait_for_stop_done(&done);
return done.executed ? done.ret : -ENOENT;
}
@@ -137,11 +155,12 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
/* static data for stop_cpus */
static DEFINE_MUTEX(stop_cpus_mutex);
+static DEFINE_MUTEX(stopper_lock);
static DEFINE_PER_CPU(struct cpu_stop_work, stop_cpus_work);
static void queue_stop_cpus_work(const struct cpumask *cpumask,
cpu_stop_fn_t fn, void *arg,
- struct cpu_stop_done *done)
+ struct cpu_stop_done *done, bool inactive)
{
struct cpu_stop_work *work;
unsigned int cpu;
@@ -155,14 +174,18 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask,
}
/*
- * Disable preemption while queueing to avoid getting
- * preempted by a stopper which might wait for other stoppers
- * to enter @fn which can lead to deadlock.
+ * Make sure that all work is queued on all cpus before we
+ * any of the cpus can execute it.
*/
- preempt_disable();
+ if (!inactive) {
+ mutex_lock(&stopper_lock);
+ } else {
+ while (!mutex_trylock(&stopper_lock))
+ cpu_relax();
+ }
for_each_cpu(cpu, cpumask)
cpu_stop_queue_work(cpu, &per_cpu(stop_cpus_work, cpu));
- preempt_enable();
+ mutex_unlock(&stopper_lock);
}
static int __stop_cpus(const struct cpumask *cpumask,
@@ -171,8 +194,8 @@ static int __stop_cpus(const struct cpumask *cpumask,
struct cpu_stop_done done;
cpu_stop_init_done(&done, cpumask_weight(cpumask));
- queue_stop_cpus_work(cpumask, fn, arg, &done);
- wait_for_completion(&done.completion);
+ queue_stop_cpus_work(cpumask, fn, arg, &done, false);
+ wait_for_stop_done(&done);
return done.executed ? done.ret : -ENOENT;
}
@@ -251,9 +274,9 @@ static int cpu_stop_should_run(unsigned int cpu)
unsigned long flags;
int run;
- spin_lock_irqsave(&stopper->lock, flags);
+ raw_spin_lock_irqsave(&stopper->lock, flags);
run = !list_empty(&stopper->works);
- spin_unlock_irqrestore(&stopper->lock, flags);
+ raw_spin_unlock_irqrestore(&stopper->lock, flags);
return run;
}
@@ -265,13 +288,13 @@ static void cpu_stopper_thread(unsigned int cpu)
repeat:
work = NULL;
- spin_lock_irq(&stopper->lock);
+ raw_spin_lock_irq(&stopper->lock);
if (!list_empty(&stopper->works)) {
work = list_first_entry(&stopper->works,
struct cpu_stop_work, list);
list_del_init(&work->list);
}
- spin_unlock_irq(&stopper->lock);
+ raw_spin_unlock_irq(&stopper->lock);
if (work) {
cpu_stop_fn_t fn = work->fn;
@@ -279,6 +302,16 @@ repeat:
struct cpu_stop_done *done = work->done;
char ksym_buf[KSYM_NAME_LEN] __maybe_unused;
+ /*
+ * Wait until the stopper finished scheduling on all
+ * cpus
+ */
+ mutex_lock(&stopper_lock);
+ /*
+ * Let other cpu threads continue as well
+ */
+ mutex_unlock(&stopper_lock);
+
/* cpu stop callbacks are not allowed to sleep */
preempt_disable();
@@ -293,7 +326,13 @@ repeat:
kallsyms_lookup((unsigned long)fn, NULL, NULL, NULL,
ksym_buf), arg);
+ /*
+ * Make sure that the wakeup and setting done->waiter
+ * to NULL is atomic.
+ */
+ local_irq_disable();
cpu_stop_signal_done(done, true);
+ local_irq_enable();
goto repeat;
}
}
@@ -312,20 +351,20 @@ static void cpu_stop_park(unsigned int cpu)
unsigned long flags;
/* drain remaining works */
- spin_lock_irqsave(&stopper->lock, flags);
+ raw_spin_lock_irqsave(&stopper->lock, flags);
list_for_each_entry(work, &stopper->works, list)
cpu_stop_signal_done(work->done, false);
stopper->enabled = false;
- spin_unlock_irqrestore(&stopper->lock, flags);
+ raw_spin_unlock_irqrestore(&stopper->lock, flags);
}
static void cpu_stop_unpark(unsigned int cpu)
{
struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
- spin_lock_irq(&stopper->lock);
+ raw_spin_lock_irq(&stopper->lock);
stopper->enabled = true;
- spin_unlock_irq(&stopper->lock);
+ raw_spin_unlock_irq(&stopper->lock);
}
static struct smp_hotplug_thread cpu_stop_threads = {
@@ -347,7 +386,7 @@ static int __init cpu_stop_init(void)
for_each_possible_cpu(cpu) {
struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
- spin_lock_init(&stopper->lock);
+ raw_spin_lock_init(&stopper->lock);
INIT_LIST_HEAD(&stopper->works);
}
@@ -530,11 +569,11 @@ int stop_machine_from_inactive_cpu(int (*fn)(void *), void *data,
set_state(&smdata, STOPMACHINE_PREPARE);
cpu_stop_init_done(&done, num_active_cpus());
queue_stop_cpus_work(cpu_active_mask, stop_machine_cpu_stop, &smdata,
- &done);
+ &done, true);
ret = stop_machine_cpu_stop(&smdata);
/* Busy wait for completion. */
- while (!completion_done(&done.completion))
+ while (atomic_read(&done.nr_todo))
cpu_relax();
mutex_unlock(&stop_cpus_mutex);
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index a6a5bf5..23d7203 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -73,7 +73,8 @@ static struct clocksource clocksource_jiffies = {
.shift = JIFFIES_SHIFT,
};
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(jiffies_lock);
+__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(jiffies_lock);
+__cacheline_aligned_in_smp seqcount_t jiffies_seq;
#if (BITS_PER_LONG < 64)
u64 get_jiffies_64(void)
@@ -82,9 +83,9 @@ u64 get_jiffies_64(void)
u64 ret;
do {
- seq = read_seqbegin(&jiffies_lock);
+ seq = read_seqcount_begin(&jiffies_seq);
ret = jiffies_64;
- } while (read_seqretry(&jiffies_lock, seq));
+ } while (read_seqcount_retry(&jiffies_seq, seq));
return ret;
}
EXPORT_SYMBOL(get_jiffies_64);
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index af8d1d4..d6132cd 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -10,6 +10,7 @@
#include <linux/workqueue.h>
#include <linux/hrtimer.h>
#include <linux/jiffies.h>
+#include <linux/kthread.h>
#include <linux/math64.h>
#include <linux/timex.h>
#include <linux/time.h>
@@ -517,10 +518,49 @@ static void sync_cmos_clock(struct work_struct *work)
schedule_delayed_work(&sync_cmos_work, timespec_to_jiffies(&next));
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * RT can not call schedule_delayed_work from real interrupt context.
+ * Need to make a thread to do the real work.
+ */
+static struct task_struct *cmos_delay_thread;
+static bool do_cmos_delay;
+
+static int run_cmos_delay(void *ignore)
+{
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (do_cmos_delay) {
+ do_cmos_delay = false;
+ schedule_delayed_work(&sync_cmos_work, 0);
+ }
+ schedule();
+ }
+ __set_current_state(TASK_RUNNING);
+ return 0;
+}
+
+void ntp_notify_cmos_timer(void)
+{
+ do_cmos_delay = true;
+ /* Make visible before waking up process */
+ smp_wmb();
+ wake_up_process(cmos_delay_thread);
+}
+
+static __init int create_cmos_delay_thread(void)
+{
+ cmos_delay_thread = kthread_run(run_cmos_delay, NULL, "kcmosdelayd");
+ BUG_ON(!cmos_delay_thread);
+ return 0;
+}
+early_initcall(create_cmos_delay_thread);
+#else
void ntp_notify_cmos_timer(void)
{
schedule_delayed_work(&sync_cmos_work, 0);
}
+#endif /* CONFIG_PREEMPT_RT_FULL */
#else
void ntp_notify_cmos_timer(void) { }
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 64522ec..1b80eb0 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -63,13 +63,15 @@ int tick_is_oneshot_available(void)
static void tick_periodic(int cpu)
{
if (tick_do_timer_cpu == cpu) {
- write_seqlock(&jiffies_lock);
+ raw_spin_lock(&jiffies_lock);
+ write_seqcount_begin(&jiffies_seq);
/* Keep track of the next tick event */
tick_next_period = ktime_add(tick_next_period, tick_period);
do_timer(1);
- write_sequnlock(&jiffies_lock);
+ write_seqcount_end(&jiffies_seq);
+ raw_spin_unlock(&jiffies_lock);
}
update_process_times(user_mode(get_irq_regs()));
@@ -130,9 +132,9 @@ void tick_setup_periodic(struct clock_event_device *dev, int broadcast)
ktime_t next;
do {
- seq = read_seqbegin(&jiffies_lock);
+ seq = read_seqcount_begin(&jiffies_seq);
next = tick_next_period;
- } while (read_seqretry(&jiffies_lock, seq));
+ } while (read_seqcount_retry(&jiffies_seq, seq));
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index bc906ca..7e5e7f8 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -4,7 +4,8 @@
#include <linux/hrtimer.h>
#include <linux/tick.h>
-extern seqlock_t jiffies_lock;
+extern raw_spinlock_t jiffies_lock;
+extern seqcount_t jiffies_seq;
#define CS_NAME_LEN 32
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index ea20f7d..3740f28 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -62,7 +62,8 @@ static void tick_do_update_jiffies64(ktime_t now)
return;
/* Reevalute with jiffies_lock held */
- write_seqlock(&jiffies_lock);
+ raw_spin_lock(&jiffies_lock);
+ write_seqcount_begin(&jiffies_seq);
delta = ktime_sub(now, last_jiffies_update);
if (delta.tv64 >= tick_period.tv64) {
@@ -85,7 +86,8 @@ static void tick_do_update_jiffies64(ktime_t now)
/* Keep the tick_next_period variable up to date */
tick_next_period = ktime_add(last_jiffies_update, tick_period);
}
- write_sequnlock(&jiffies_lock);
+ write_seqcount_end(&jiffies_seq);
+ raw_spin_unlock(&jiffies_lock);
}
/*
@@ -95,12 +97,14 @@ static ktime_t tick_init_jiffy_update(void)
{
ktime_t period;
- write_seqlock(&jiffies_lock);
+ raw_spin_lock(&jiffies_lock);
+ write_seqcount_begin(&jiffies_seq);
/* Did we start the jiffies update yet ? */
if (last_jiffies_update.tv64 == 0)
last_jiffies_update = tick_next_period;
period = last_jiffies_update;
- write_sequnlock(&jiffies_lock);
+ write_seqcount_end(&jiffies_seq);
+ raw_spin_unlock(&jiffies_lock);
return period;
}
@@ -217,6 +221,7 @@ static void nohz_full_kick_work_func(struct irq_work *work)
static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
.func = nohz_full_kick_work_func,
+ .flags = IRQ_WORK_HARD_IRQ,
};
/*
@@ -538,11 +543,11 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
/* Read jiffies and the time when jiffies were updated last */
do {
- seq = read_seqbegin(&jiffies_lock);
+ seq = read_seqcount_begin(&jiffies_seq);
last_update = last_jiffies_update;
last_jiffies = jiffies;
time_delta = timekeeping_max_deferment();
- } while (read_seqretry(&jiffies_lock, seq));
+ } while (read_seqcount_retry(&jiffies_seq, seq));
if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) ||
arch_needs_cpu(cpu) || irq_work_needs_cpu()) {
@@ -720,14 +725,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
return false;
if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
- static int ratelimit;
-
- if (ratelimit < 10 &&
- (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
- pr_warn("NOHZ: local_softirq_pending %02x\n",
- (unsigned int) local_softirq_pending());
- ratelimit++;
- }
+ softirq_check_pending_idle();
return false;
}
@@ -1112,6 +1110,7 @@ void tick_setup_sched_timer(void)
* Emulate tick processing via per-CPU hrtimers:
*/
hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ ts->sched_timer.irqsafe = 1;
ts->sched_timer.function = tick_sched_timer;
/* Get the next period (per cpu) */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index bfca770..d3150a7 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1754,7 +1754,9 @@ EXPORT_SYMBOL(hardpps);
*/
void xtime_update(unsigned long ticks)
{
- write_seqlock(&jiffies_lock);
+ raw_spin_lock(&jiffies_lock);
+ write_seqcount_begin(&jiffies_seq);
do_timer(ticks);
- write_sequnlock(&jiffies_lock);
+ write_seqcount_end(&jiffies_seq);
+ raw_spin_unlock(&jiffies_lock);
}
diff --git a/kernel/timer.c b/kernel/timer.c
index 4296d13..cc34e42 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -78,6 +78,9 @@ struct tvec_root {
struct tvec_base {
spinlock_t lock;
struct timer_list *running_timer;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ wait_queue_head_t wait_for_running_timer;
+#endif
unsigned long timer_jiffies;
unsigned long next_timer;
unsigned long active_timers;
@@ -720,6 +723,36 @@ static struct tvec_base *lock_timer_base(struct timer_list *timer,
}
}
+#ifndef CONFIG_PREEMPT_RT_FULL
+static inline struct tvec_base *switch_timer_base(struct timer_list *timer,
+ struct tvec_base *old,
+ struct tvec_base *new)
+{
+ /* See the comment in lock_timer_base() */
+ timer_set_base(timer, NULL);
+ spin_unlock(&old->lock);
+ spin_lock(&new->lock);
+ timer_set_base(timer, new);
+ return new;
+}
+#else
+static inline struct tvec_base *switch_timer_base(struct timer_list *timer,
+ struct tvec_base *old,
+ struct tvec_base *new)
+{
+ /*
+ * We cannot do the above because we might be preempted and
+ * then the preempter would see NULL and loop forever.
+ */
+ if (spin_trylock(&new->lock)) {
+ timer_set_base(timer, new);
+ spin_unlock(&old->lock);
+ return new;
+ }
+ return old;
+}
+#endif
+
static inline int
__mod_timer(struct timer_list *timer, unsigned long expires,
bool pending_only, int pinned)
@@ -739,12 +772,15 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
debug_activate(timer, expires);
+ preempt_disable_rt();
cpu = smp_processor_id();
#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu))
cpu = get_nohz_timer_target();
#endif
+ preempt_enable_rt();
+
new_base = per_cpu(tvec_bases, cpu);
if (base != new_base) {
@@ -755,14 +791,8 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
* handler yet has not finished. This also guarantees that
* the timer is serialized wrt itself.
*/
- if (likely(base->running_timer != timer)) {
- /* See the comment in lock_timer_base() */
- timer_set_base(timer, NULL);
- spin_unlock(&base->lock);
- base = new_base;
- spin_lock(&base->lock);
- timer_set_base(timer, base);
- }
+ if (likely(base->running_timer != timer))
+ base = switch_timer_base(timer, base, new_base);
}
timer->expires = expires;
@@ -945,6 +975,29 @@ void add_timer_on(struct timer_list *timer, int cpu)
}
EXPORT_SYMBOL_GPL(add_timer_on);
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Wait for a running timer
+ */
+static void wait_for_running_timer(struct timer_list *timer)
+{
+ struct tvec_base *base = timer->base;
+
+ if (base->running_timer == timer)
+ wait_event(base->wait_for_running_timer,
+ base->running_timer != timer);
+}
+
+# define wakeup_timer_waiters(b) wake_up(&(b)->wait_for_running_timer)
+#else
+static inline void wait_for_running_timer(struct timer_list *timer)
+{
+ cpu_relax();
+}
+
+# define wakeup_timer_waiters(b) do { } while (0)
+#endif
+
/**
* del_timer - deactive a timer.
* @timer: the timer to be deactivated
@@ -1002,7 +1055,7 @@ int try_to_del_timer_sync(struct timer_list *timer)
}
EXPORT_SYMBOL(try_to_del_timer_sync);
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
/**
* del_timer_sync - deactivate a timer and wait for the handler to finish.
* @timer: the timer to be deactivated
@@ -1062,7 +1115,7 @@ int del_timer_sync(struct timer_list *timer)
int ret = try_to_del_timer_sync(timer);
if (ret >= 0)
return ret;
- cpu_relax();
+ wait_for_running_timer(timer);
}
}
EXPORT_SYMBOL(del_timer_sync);
@@ -1179,15 +1232,17 @@ static inline void __run_timers(struct tvec_base *base)
if (irqsafe) {
spin_unlock(&base->lock);
call_timer_fn(timer, fn, data);
+ base->running_timer = NULL;
spin_lock(&base->lock);
} else {
spin_unlock_irq(&base->lock);
call_timer_fn(timer, fn, data);
+ base->running_timer = NULL;
spin_lock_irq(&base->lock);
}
}
}
- base->running_timer = NULL;
+ wakeup_timer_waiters(base);
spin_unlock_irq(&base->lock);
}
@@ -1327,17 +1382,31 @@ unsigned long get_next_timer_interrupt(unsigned long now)
if (cpu_is_offline(smp_processor_id()))
return expires;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /*
+ * On PREEMPT_RT we cannot sleep here. If the trylock does not
+ * succeed then we return the worst-case 'expires in 1 tick'
+ * value. We use the rt functions here directly to avoid a
+ * migrate_disable() call.
+ */
+ if (!spin_do_trylock(&base->lock))
+ return now + 1;
+#else
spin_lock(&base->lock);
+#endif
if (base->active_timers) {
if (time_before_eq(base->next_timer, base->timer_jiffies))
base->next_timer = __next_timer_interrupt(base);
expires = base->next_timer;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ rt_spin_unlock_after_trylock_in_irq(&base->lock);
+#else
spin_unlock(&base->lock);
+#endif
if (time_before_eq(expires, now))
return now;
-
return cmp_next_hrtimer_event(now, expires);
}
#endif
@@ -1353,13 +1422,13 @@ void update_process_times(int user_tick)
/* Note: this timer irq context must be accounted for as well. */
account_process_tick(p, user_tick);
+ scheduler_tick();
run_local_timers();
rcu_check_callbacks(cpu, user_tick);
-#ifdef CONFIG_IRQ_WORK
+#if defined(CONFIG_IRQ_WORK)
if (in_irq())
irq_work_run();
#endif
- scheduler_tick();
run_posix_cpu_timers(p);
}
@@ -1370,7 +1439,9 @@ static void run_timer_softirq(struct softirq_action *h)
{
struct tvec_base *base = __this_cpu_read(tvec_bases);
- hrtimer_run_pending();
+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
+ irq_work_run();
+#endif
if (time_after_eq(jiffies, base->timer_jiffies))
__run_timers(base);
@@ -1381,8 +1452,39 @@ static void run_timer_softirq(struct softirq_action *h)
*/
void run_local_timers(void)
{
+ struct tvec_base *base = __this_cpu_read(tvec_bases);
+
hrtimer_run_queues();
- raise_softirq(TIMER_SOFTIRQ);
+ /*
+ * We can access this lockless as we are in the timer
+ * interrupt. If there are no timers queued, nothing to do in
+ * the timer softirq.
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /* On RT, irq work runs from softirq */
+ if (irq_work_needs_cpu()) {
+ raise_softirq(TIMER_SOFTIRQ);
+ return;
+ }
+
+ if (!spin_do_trylock(&base->lock)) {
+ raise_softirq(TIMER_SOFTIRQ);
+ return;
+ }
+#endif
+
+ if (!base->active_timers)
+ goto out;
+
+ /* Check whether the next pending timer has expired */
+ if (time_before_eq(base->next_timer, jiffies))
+ raise_softirq(TIMER_SOFTIRQ);
+out:
+#ifdef CONFIG_PREEMPT_RT_FULL
+ rt_spin_unlock_after_trylock_in_irq(&base->lock);
+#endif
+ /* The ; ensures that gcc won't complain in the !RT case */
+ ;
}
#ifdef __ARCH_WANT_SYS_ALARM
@@ -1547,6 +1649,9 @@ static int init_timers_cpu(int cpu)
base = per_cpu(tvec_bases, cpu);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ init_waitqueue_head(&base->wait_for_running_timer);
+#endif
for (j = 0; j < TVN_SIZE; j++) {
INIT_LIST_HEAD(base->tv5.vec + j);
@@ -1585,7 +1690,7 @@ static void migrate_timers(int cpu)
BUG_ON(cpu_online(cpu));
old_base = per_cpu(tvec_bases, cpu);
- new_base = get_cpu_var(tvec_bases);
+ new_base = get_local_var(tvec_bases);
/*
* The caller is globally serialized and nobody else
* takes two locks at once, deadlock is not possible.
@@ -1606,7 +1711,7 @@ static void migrate_timers(int cpu)
spin_unlock(&old_base->lock);
spin_unlock_irq(&new_base->lock);
- put_cpu_var(tvec_bases);
+ put_local_var(tvec_bases);
}
#endif /* CONFIG_HOTPLUG_CPU */
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 015f85a..bbe95b9 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -192,6 +192,24 @@ config IRQSOFF_TRACER
enabled. This option and the preempt-off timing option can be
used together or separately.)
+config INTERRUPT_OFF_HIST
+ bool "Interrupts-off Latency Histogram"
+ depends on IRQSOFF_TRACER
+ help
+ This option generates continuously updated histograms (one per cpu)
+ of the duration of time periods with interrupts disabled. The
+ histograms are disabled by default. To enable them, write a non-zero
+ number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/preemptirqsoff
+
+ If PREEMPT_OFF_HIST is also selected, additional histograms (one
+ per cpu) are generated that accumulate the duration of time periods
+ when both interrupts and preemption are disabled. The histogram data
+ will be located in the debug file system at
+
+ /sys/kernel/debug/tracing/latency_hist/irqsoff
+
config PREEMPT_TRACER
bool "Preemption-off Latency Tracer"
default n
@@ -216,6 +234,24 @@ config PREEMPT_TRACER
enabled. This option and the irqs-off timing option can be
used together or separately.)
+config PREEMPT_OFF_HIST
+ bool "Preemption-off Latency Histogram"
+ depends on PREEMPT_TRACER
+ help
+ This option generates continuously updated histograms (one per cpu)
+ of the duration of time periods with preemption disabled. The
+ histograms are disabled by default. To enable them, write a non-zero
+ number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/preemptirqsoff
+
+ If INTERRUPT_OFF_HIST is also selected, additional histograms (one
+ per cpu) are generated that accumulate the duration of time periods
+ when both interrupts and preemption are disabled. The histogram data
+ will be located in the debug file system at
+
+ /sys/kernel/debug/tracing/latency_hist/preemptoff
+
config SCHED_TRACER
bool "Scheduling Latency Tracer"
select GENERIC_TRACER
@@ -226,6 +262,74 @@ config SCHED_TRACER
This tracer tracks the latency of the highest priority task
to be scheduled in, starting from the point it has woken up.
+config WAKEUP_LATENCY_HIST
+ bool "Scheduling Latency Histogram"
+ depends on SCHED_TRACER
+ help
+ This option generates continuously updated histograms (one per cpu)
+ of the scheduling latency of the highest priority task.
+ The histograms are disabled by default. To enable them, write a
+ non-zero number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/wakeup
+
+ Two different algorithms are used, one to determine the latency of
+ processes that exclusively use the highest priority of the system and
+ another one to determine the latency of processes that share the
+ highest system priority with other processes. The former is used to
+ improve hardware and system software, the latter to optimize the
+ priority design of a given system. The histogram data will be
+ located in the debug file system at
+
+ /sys/kernel/debug/tracing/latency_hist/wakeup
+
+ and
+
+ /sys/kernel/debug/tracing/latency_hist/wakeup/sharedprio
+
+ If both Scheduling Latency Histogram and Missed Timer Offsets
+ Histogram are selected, additional histogram data will be collected
+ that contain, in addition to the wakeup latency, the timer latency, in
+ case the wakeup was triggered by an expired timer. These histograms
+ are available in the
+
+ /sys/kernel/debug/tracing/latency_hist/timerandwakeup
+
+ directory. They reflect the apparent interrupt and scheduling latency
+ and are best suitable to determine the worst-case latency of a given
+ system. To enable these histograms, write a non-zero number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/timerandwakeup
+
+config MISSED_TIMER_OFFSETS_HIST
+ depends on HIGH_RES_TIMERS
+ select GENERIC_TRACER
+ bool "Missed Timer Offsets Histogram"
+ help
+ Generate a histogram of missed timer offsets in microseconds. The
+ histograms are disabled by default. To enable them, write a non-zero
+ number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/missed_timer_offsets
+
+ The histogram data will be located in the debug file system at
+
+ /sys/kernel/debug/tracing/latency_hist/missed_timer_offsets
+
+ If both Scheduling Latency Histogram and Missed Timer Offsets
+ Histogram are selected, additional histogram data will be collected
+ that contain, in addition to the wakeup latency, the timer latency, in
+ case the wakeup was triggered by an expired timer. These histograms
+ are available in the
+
+ /sys/kernel/debug/tracing/latency_hist/timerandwakeup
+
+ directory. They reflect the apparent interrupt and scheduling latency
+ and are best suitable to determine the worst-case latency of a given
+ system. To enable these histograms, write a non-zero number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/timerandwakeup
+
config ENABLE_DEFAULT_TRACERS
bool "Trace process context switches and events"
depends on !GENERIC_TRACER
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index d7e2068..f5e0243 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -34,6 +34,10 @@ obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o
obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o
obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o
+obj-$(CONFIG_INTERRUPT_OFF_HIST) += latency_hist.o
+obj-$(CONFIG_PREEMPT_OFF_HIST) += latency_hist.o
+obj-$(CONFIG_WAKEUP_LATENCY_HIST) += latency_hist.o
+obj-$(CONFIG_MISSED_TIMER_OFFSETS_HIST) += latency_hist.o
obj-$(CONFIG_NOP_TRACER) += trace_nop.o
obj-$(CONFIG_STACK_TRACER) += trace_stack.o
obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
diff --git a/kernel/trace/latency_hist.c b/kernel/trace/latency_hist.c
new file mode 100644
index 0000000..66a69eb
--- /dev/null
+++ b/kernel/trace/latency_hist.c
@@ -0,0 +1,1178 @@
+/*
+ * kernel/trace/latency_hist.c
+ *
+ * Add support for histograms of preemption-off latency and
+ * interrupt-off latency and wakeup latency, it depends on
+ * Real-Time Preemption Support.
+ *
+ * Copyright (C) 2005 MontaVista Software, Inc.
+ * Yi Yang <yyang@ch.mvista.com>
+ *
+ * Converted to work with the new latency tracer.
+ * Copyright (C) 2008 Red Hat, Inc.
+ * Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/percpu.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+#include <linux/sched.h>
+#include <linux/sched/rt.h>
+#include <linux/slab.h>
+#include <linux/atomic.h>
+#include <asm/div64.h>
+
+#include "trace.h"
+#include <trace/events/sched.h>
+
+#define NSECS_PER_USECS 1000L
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/hist.h>
+
+enum {
+ IRQSOFF_LATENCY = 0,
+ PREEMPTOFF_LATENCY,
+ PREEMPTIRQSOFF_LATENCY,
+ WAKEUP_LATENCY,
+ WAKEUP_LATENCY_SHAREDPRIO,
+ MISSED_TIMER_OFFSETS,
+ TIMERANDWAKEUP_LATENCY,
+ MAX_LATENCY_TYPE,
+};
+
+#define MAX_ENTRY_NUM 10240
+
+struct hist_data {
+ atomic_t hist_mode; /* 0 log, 1 don't log */
+ long offset; /* set it to MAX_ENTRY_NUM/2 for a bipolar scale */
+ long min_lat;
+ long max_lat;
+ unsigned long long below_hist_bound_samples;
+ unsigned long long above_hist_bound_samples;
+ long long accumulate_lat;
+ unsigned long long total_samples;
+ unsigned long long hist_array[MAX_ENTRY_NUM];
+};
+
+struct enable_data {
+ int latency_type;
+ int enabled;
+};
+
+static char *latency_hist_dir_root = "latency_hist";
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+static DEFINE_PER_CPU(struct hist_data, irqsoff_hist);
+static char *irqsoff_hist_dir = "irqsoff";
+static DEFINE_PER_CPU(cycles_t, hist_irqsoff_start);
+static DEFINE_PER_CPU(int, hist_irqsoff_counting);
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+static DEFINE_PER_CPU(struct hist_data, preemptoff_hist);
+static char *preemptoff_hist_dir = "preemptoff";
+static DEFINE_PER_CPU(cycles_t, hist_preemptoff_start);
+static DEFINE_PER_CPU(int, hist_preemptoff_counting);
+#endif
+
+#if defined(CONFIG_PREEMPT_OFF_HIST) && defined(CONFIG_INTERRUPT_OFF_HIST)
+static DEFINE_PER_CPU(struct hist_data, preemptirqsoff_hist);
+static char *preemptirqsoff_hist_dir = "preemptirqsoff";
+static DEFINE_PER_CPU(cycles_t, hist_preemptirqsoff_start);
+static DEFINE_PER_CPU(int, hist_preemptirqsoff_counting);
+#endif
+
+#if defined(CONFIG_PREEMPT_OFF_HIST) || defined(CONFIG_INTERRUPT_OFF_HIST)
+static notrace void probe_preemptirqsoff_hist(void *v, int reason, int start);
+static struct enable_data preemptirqsoff_enabled_data = {
+ .latency_type = PREEMPTIRQSOFF_LATENCY,
+ .enabled = 0,
+};
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+struct maxlatproc_data {
+ char comm[FIELD_SIZEOF(struct task_struct, comm)];
+ char current_comm[FIELD_SIZEOF(struct task_struct, comm)];
+ int pid;
+ int current_pid;
+ int prio;
+ int current_prio;
+ long latency;
+ long timeroffset;
+ cycle_t timestamp;
+};
+#endif
+
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+static DEFINE_PER_CPU(struct hist_data, wakeup_latency_hist);
+static DEFINE_PER_CPU(struct hist_data, wakeup_latency_hist_sharedprio);
+static char *wakeup_latency_hist_dir = "wakeup";
+static char *wakeup_latency_hist_dir_sharedprio = "sharedprio";
+static notrace void probe_wakeup_latency_hist_start(void *v,
+ struct task_struct *p, int success);
+static notrace void probe_wakeup_latency_hist_stop(void *v,
+ struct task_struct *prev, struct task_struct *next);
+static notrace void probe_sched_migrate_task(void *,
+ struct task_struct *task, int cpu);
+static struct enable_data wakeup_latency_enabled_data = {
+ .latency_type = WAKEUP_LATENCY,
+ .enabled = 0,
+};
+static DEFINE_PER_CPU(struct maxlatproc_data, wakeup_maxlatproc);
+static DEFINE_PER_CPU(struct maxlatproc_data, wakeup_maxlatproc_sharedprio);
+static DEFINE_PER_CPU(struct task_struct *, wakeup_task);
+static DEFINE_PER_CPU(int, wakeup_sharedprio);
+static unsigned long wakeup_pid;
+#endif
+
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+static DEFINE_PER_CPU(struct hist_data, missed_timer_offsets);
+static char *missed_timer_offsets_dir = "missed_timer_offsets";
+static notrace void probe_hrtimer_interrupt(void *v, int cpu,
+ long long offset, struct task_struct *curr, struct task_struct *task);
+static struct enable_data missed_timer_offsets_enabled_data = {
+ .latency_type = MISSED_TIMER_OFFSETS,
+ .enabled = 0,
+};
+static DEFINE_PER_CPU(struct maxlatproc_data, missed_timer_offsets_maxlatproc);
+static unsigned long missed_timer_offsets_pid;
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static DEFINE_PER_CPU(struct hist_data, timerandwakeup_latency_hist);
+static char *timerandwakeup_latency_hist_dir = "timerandwakeup";
+static struct enable_data timerandwakeup_enabled_data = {
+ .latency_type = TIMERANDWAKEUP_LATENCY,
+ .enabled = 0,
+};
+static DEFINE_PER_CPU(struct maxlatproc_data, timerandwakeup_maxlatproc);
+#endif
+
+void notrace latency_hist(int latency_type, int cpu, long latency,
+ long timeroffset, cycle_t stop,
+ struct task_struct *p)
+{
+ struct hist_data *my_hist;
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ struct maxlatproc_data *mp = NULL;
+#endif
+
+ if (!cpu_possible(cpu) || latency_type < 0 ||
+ latency_type >= MAX_LATENCY_TYPE)
+ return;
+
+ switch (latency_type) {
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ case IRQSOFF_LATENCY:
+ my_hist = &per_cpu(irqsoff_hist, cpu);
+ break;
+#endif
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ case PREEMPTOFF_LATENCY:
+ my_hist = &per_cpu(preemptoff_hist, cpu);
+ break;
+#endif
+#if defined(CONFIG_PREEMPT_OFF_HIST) && defined(CONFIG_INTERRUPT_OFF_HIST)
+ case PREEMPTIRQSOFF_LATENCY:
+ my_hist = &per_cpu(preemptirqsoff_hist, cpu);
+ break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ case WAKEUP_LATENCY:
+ my_hist = &per_cpu(wakeup_latency_hist, cpu);
+ mp = &per_cpu(wakeup_maxlatproc, cpu);
+ break;
+ case WAKEUP_LATENCY_SHAREDPRIO:
+ my_hist = &per_cpu(wakeup_latency_hist_sharedprio, cpu);
+ mp = &per_cpu(wakeup_maxlatproc_sharedprio, cpu);
+ break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ case MISSED_TIMER_OFFSETS:
+ my_hist = &per_cpu(missed_timer_offsets, cpu);
+ mp = &per_cpu(missed_timer_offsets_maxlatproc, cpu);
+ break;
+#endif
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ case TIMERANDWAKEUP_LATENCY:
+ my_hist = &per_cpu(timerandwakeup_latency_hist, cpu);
+ mp = &per_cpu(timerandwakeup_maxlatproc, cpu);
+ break;
+#endif
+
+ default:
+ return;
+ }
+
+ latency += my_hist->offset;
+
+ if (atomic_read(&my_hist->hist_mode) == 0)
+ return;
+
+ if (latency < 0 || latency >= MAX_ENTRY_NUM) {
+ if (latency < 0)
+ my_hist->below_hist_bound_samples++;
+ else
+ my_hist->above_hist_bound_samples++;
+ } else
+ my_hist->hist_array[latency]++;
+
+ if (unlikely(latency > my_hist->max_lat ||
+ my_hist->min_lat == LONG_MAX)) {
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ if (latency_type == WAKEUP_LATENCY ||
+ latency_type == WAKEUP_LATENCY_SHAREDPRIO ||
+ latency_type == MISSED_TIMER_OFFSETS ||
+ latency_type == TIMERANDWAKEUP_LATENCY) {
+ strncpy(mp->comm, p->comm, sizeof(mp->comm));
+ strncpy(mp->current_comm, current->comm,
+ sizeof(mp->current_comm));
+ mp->pid = task_pid_nr(p);
+ mp->current_pid = task_pid_nr(current);
+ mp->prio = p->prio;
+ mp->current_prio = current->prio;
+ mp->latency = latency;
+ mp->timeroffset = timeroffset;
+ mp->timestamp = stop;
+ }
+#endif
+ my_hist->max_lat = latency;
+ }
+ if (unlikely(latency < my_hist->min_lat))
+ my_hist->min_lat = latency;
+ my_hist->total_samples++;
+ my_hist->accumulate_lat += latency;
+}
+
+static void *l_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t *index_ptr = NULL;
+ loff_t index = *pos;
+ struct hist_data *my_hist = m->private;
+
+ if (index == 0) {
+ char minstr[32], avgstr[32], maxstr[32];
+
+ atomic_dec(&my_hist->hist_mode);
+
+ if (likely(my_hist->total_samples)) {
+ long avg = (long) div64_s64(my_hist->accumulate_lat,
+ my_hist->total_samples);
+ snprintf(minstr, sizeof(minstr), "%ld",
+ my_hist->min_lat - my_hist->offset);
+ snprintf(avgstr, sizeof(avgstr), "%ld",
+ avg - my_hist->offset);
+ snprintf(maxstr, sizeof(maxstr), "%ld",
+ my_hist->max_lat - my_hist->offset);
+ } else {
+ strcpy(minstr, "<undef>");
+ strcpy(avgstr, minstr);
+ strcpy(maxstr, minstr);
+ }
+
+ seq_printf(m, "#Minimum latency: %s microseconds\n"
+ "#Average latency: %s microseconds\n"
+ "#Maximum latency: %s microseconds\n"
+ "#Total samples: %llu\n"
+ "#There are %llu samples lower than %ld"
+ " microseconds.\n"
+ "#There are %llu samples greater or equal"
+ " than %ld microseconds.\n"
+ "#usecs\t%16s\n",
+ minstr, avgstr, maxstr,
+ my_hist->total_samples,
+ my_hist->below_hist_bound_samples,
+ -my_hist->offset,
+ my_hist->above_hist_bound_samples,
+ MAX_ENTRY_NUM - my_hist->offset,
+ "samples");
+ }
+ if (index < MAX_ENTRY_NUM) {
+ index_ptr = kmalloc(sizeof(loff_t), GFP_KERNEL);
+ if (index_ptr)
+ *index_ptr = index;
+ }
+
+ return index_ptr;
+}
+
+static void *l_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ loff_t *index_ptr = p;
+ struct hist_data *my_hist = m->private;
+
+ if (++*pos >= MAX_ENTRY_NUM) {
+ atomic_inc(&my_hist->hist_mode);
+ return NULL;
+ }
+ *index_ptr = *pos;
+ return index_ptr;
+}
+
+static void l_stop(struct seq_file *m, void *p)
+{
+ kfree(p);
+}
+
+static int l_show(struct seq_file *m, void *p)
+{
+ int index = *(loff_t *) p;
+ struct hist_data *my_hist = m->private;
+
+ seq_printf(m, "%6ld\t%16llu\n", index - my_hist->offset,
+ my_hist->hist_array[index]);
+ return 0;
+}
+
+static const struct seq_operations latency_hist_seq_op = {
+ .start = l_start,
+ .next = l_next,
+ .stop = l_stop,
+ .show = l_show
+};
+
+static int latency_hist_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ ret = seq_open(file, &latency_hist_seq_op);
+ if (!ret) {
+ struct seq_file *seq = file->private_data;
+ seq->private = inode->i_private;
+ }
+ return ret;
+}
+
+static const struct file_operations latency_hist_fops = {
+ .open = latency_hist_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static void clear_maxlatprocdata(struct maxlatproc_data *mp)
+{
+ mp->comm[0] = mp->current_comm[0] = '\0';
+ mp->prio = mp->current_prio = mp->pid = mp->current_pid =
+ mp->latency = mp->timeroffset = -1;
+ mp->timestamp = 0;
+}
+#endif
+
+static void hist_reset(struct hist_data *hist)
+{
+ atomic_dec(&hist->hist_mode);
+
+ memset(hist->hist_array, 0, sizeof(hist->hist_array));
+ hist->below_hist_bound_samples = 0ULL;
+ hist->above_hist_bound_samples = 0ULL;
+ hist->min_lat = LONG_MAX;
+ hist->max_lat = LONG_MIN;
+ hist->total_samples = 0ULL;
+ hist->accumulate_lat = 0LL;
+
+ atomic_inc(&hist->hist_mode);
+}
+
+static ssize_t
+latency_hist_reset(struct file *file, const char __user *a,
+ size_t size, loff_t *off)
+{
+ int cpu;
+ struct hist_data *hist = NULL;
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ struct maxlatproc_data *mp = NULL;
+#endif
+ off_t latency_type = (off_t) file->private_data;
+
+ for_each_online_cpu(cpu) {
+
+ switch (latency_type) {
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ case PREEMPTOFF_LATENCY:
+ hist = &per_cpu(preemptoff_hist, cpu);
+ break;
+#endif
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ case IRQSOFF_LATENCY:
+ hist = &per_cpu(irqsoff_hist, cpu);
+ break;
+#endif
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ case PREEMPTIRQSOFF_LATENCY:
+ hist = &per_cpu(preemptirqsoff_hist, cpu);
+ break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ case WAKEUP_LATENCY:
+ hist = &per_cpu(wakeup_latency_hist, cpu);
+ mp = &per_cpu(wakeup_maxlatproc, cpu);
+ break;
+ case WAKEUP_LATENCY_SHAREDPRIO:
+ hist = &per_cpu(wakeup_latency_hist_sharedprio, cpu);
+ mp = &per_cpu(wakeup_maxlatproc_sharedprio, cpu);
+ break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ case MISSED_TIMER_OFFSETS:
+ hist = &per_cpu(missed_timer_offsets, cpu);
+ mp = &per_cpu(missed_timer_offsets_maxlatproc, cpu);
+ break;
+#endif
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ case TIMERANDWAKEUP_LATENCY:
+ hist = &per_cpu(timerandwakeup_latency_hist, cpu);
+ mp = &per_cpu(timerandwakeup_maxlatproc, cpu);
+ break;
+#endif
+ }
+
+ hist_reset(hist);
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ if (latency_type == WAKEUP_LATENCY ||
+ latency_type == WAKEUP_LATENCY_SHAREDPRIO ||
+ latency_type == MISSED_TIMER_OFFSETS ||
+ latency_type == TIMERANDWAKEUP_LATENCY)
+ clear_maxlatprocdata(mp);
+#endif
+ }
+
+ return size;
+}
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static ssize_t
+show_pid(struct file *file, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ int r;
+ unsigned long *this_pid = file->private_data;
+
+ r = snprintf(buf, sizeof(buf), "%lu\n", *this_pid);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t do_pid(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ unsigned long pid;
+ unsigned long *this_pid = file->private_data;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = '\0';
+
+ if (kstrtoul(buf, 10, &pid))
+ return -EINVAL;
+
+ *this_pid = pid;
+
+ return cnt;
+}
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static ssize_t
+show_maxlatproc(struct file *file, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ int r;
+ struct maxlatproc_data *mp = file->private_data;
+ int strmaxlen = (TASK_COMM_LEN * 2) + (8 * 8);
+ unsigned long long t;
+ unsigned long usecs, secs;
+ char *buf;
+
+ if (mp->pid == -1 || mp->current_pid == -1) {
+ buf = "(none)\n";
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf,
+ strlen(buf));
+ }
+
+ buf = kmalloc(strmaxlen, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;
+
+ t = ns2usecs(mp->timestamp);
+ usecs = do_div(t, USEC_PER_SEC);
+ secs = (unsigned long) t;
+ r = snprintf(buf, strmaxlen,
+ "%d %d %ld (%ld) %s <- %d %d %s %lu.%06lu\n", mp->pid,
+ MAX_RT_PRIO-1 - mp->prio, mp->latency, mp->timeroffset, mp->comm,
+ mp->current_pid, MAX_RT_PRIO-1 - mp->current_prio, mp->current_comm,
+ secs, usecs);
+ r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+ kfree(buf);
+ return r;
+}
+#endif
+
+static ssize_t
+show_enable(struct file *file, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ struct enable_data *ed = file->private_data;
+ int r;
+
+ r = snprintf(buf, sizeof(buf), "%d\n", ed->enabled);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+do_enable(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ long enable;
+ struct enable_data *ed = file->private_data;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ if (kstrtoul(buf, 10, &enable))
+ return -EINVAL;
+
+ if ((enable && ed->enabled) || (!enable && !ed->enabled))
+ return cnt;
+
+ if (enable) {
+ int ret;
+
+ switch (ed->latency_type) {
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+ case PREEMPTIRQSOFF_LATENCY:
+ ret = register_trace_preemptirqsoff_hist(
+ probe_preemptirqsoff_hist, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_preemptirqsoff_hist "
+ "to trace_preemptirqsoff_hist\n");
+ return ret;
+ }
+ break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ case WAKEUP_LATENCY:
+ ret = register_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_wakeup_latency_hist_start "
+ "to trace_sched_wakeup\n");
+ return ret;
+ }
+ ret = register_trace_sched_wakeup_new(
+ probe_wakeup_latency_hist_start, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_wakeup_latency_hist_start "
+ "to trace_sched_wakeup_new\n");
+ unregister_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ return ret;
+ }
+ ret = register_trace_sched_switch(
+ probe_wakeup_latency_hist_stop, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_wakeup_latency_hist_stop "
+ "to trace_sched_switch\n");
+ unregister_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_wakeup_new(
+ probe_wakeup_latency_hist_start, NULL);
+ return ret;
+ }
+ ret = register_trace_sched_migrate_task(
+ probe_sched_migrate_task, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_sched_migrate_task "
+ "to trace_sched_migrate_task\n");
+ unregister_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_wakeup_new(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_switch(
+ probe_wakeup_latency_hist_stop, NULL);
+ return ret;
+ }
+ break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ case MISSED_TIMER_OFFSETS:
+ ret = register_trace_hrtimer_interrupt(
+ probe_hrtimer_interrupt, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_hrtimer_interrupt "
+ "to trace_hrtimer_interrupt\n");
+ return ret;
+ }
+ break;
+#endif
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ case TIMERANDWAKEUP_LATENCY:
+ if (!wakeup_latency_enabled_data.enabled ||
+ !missed_timer_offsets_enabled_data.enabled)
+ return -EINVAL;
+ break;
+#endif
+ default:
+ break;
+ }
+ } else {
+ switch (ed->latency_type) {
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+ case PREEMPTIRQSOFF_LATENCY:
+ {
+ int cpu;
+
+ unregister_trace_preemptirqsoff_hist(
+ probe_preemptirqsoff_hist, NULL);
+ for_each_online_cpu(cpu) {
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ per_cpu(hist_irqsoff_counting,
+ cpu) = 0;
+#endif
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ per_cpu(hist_preemptoff_counting,
+ cpu) = 0;
+#endif
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ per_cpu(hist_preemptirqsoff_counting,
+ cpu) = 0;
+#endif
+ }
+ }
+ break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ case WAKEUP_LATENCY:
+ {
+ int cpu;
+
+ unregister_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_wakeup_new(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_switch(
+ probe_wakeup_latency_hist_stop, NULL);
+ unregister_trace_sched_migrate_task(
+ probe_sched_migrate_task, NULL);
+
+ for_each_online_cpu(cpu) {
+ per_cpu(wakeup_task, cpu) = NULL;
+ per_cpu(wakeup_sharedprio, cpu) = 0;
+ }
+ }
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ timerandwakeup_enabled_data.enabled = 0;
+#endif
+ break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ case MISSED_TIMER_OFFSETS:
+ unregister_trace_hrtimer_interrupt(
+ probe_hrtimer_interrupt, NULL);
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ timerandwakeup_enabled_data.enabled = 0;
+#endif
+ break;
+#endif
+ default:
+ break;
+ }
+ }
+ ed->enabled = enable;
+ return cnt;
+}
+
+static const struct file_operations latency_hist_reset_fops = {
+ .open = tracing_open_generic,
+ .write = latency_hist_reset,
+};
+
+static const struct file_operations enable_fops = {
+ .open = tracing_open_generic,
+ .read = show_enable,
+ .write = do_enable,
+};
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static const struct file_operations pid_fops = {
+ .open = tracing_open_generic,
+ .read = show_pid,
+ .write = do_pid,
+};
+
+static const struct file_operations maxlatproc_fops = {
+ .open = tracing_open_generic,
+ .read = show_maxlatproc,
+};
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+static notrace void probe_preemptirqsoff_hist(void *v, int reason,
+ int starthist)
+{
+ int cpu = raw_smp_processor_id();
+ int time_set = 0;
+
+ if (starthist) {
+ cycle_t uninitialized_var(start);
+
+ if (!preempt_count() && !irqs_disabled())
+ return;
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ if ((reason == IRQS_OFF || reason == TRACE_START) &&
+ !per_cpu(hist_irqsoff_counting, cpu)) {
+ per_cpu(hist_irqsoff_counting, cpu) = 1;
+ start = ftrace_now(cpu);
+ time_set++;
+ per_cpu(hist_irqsoff_start, cpu) = start;
+ }
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ if ((reason == PREEMPT_OFF || reason == TRACE_START) &&
+ !per_cpu(hist_preemptoff_counting, cpu)) {
+ per_cpu(hist_preemptoff_counting, cpu) = 1;
+ if (!(time_set++))
+ start = ftrace_now(cpu);
+ per_cpu(hist_preemptoff_start, cpu) = start;
+ }
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ if (per_cpu(hist_irqsoff_counting, cpu) &&
+ per_cpu(hist_preemptoff_counting, cpu) &&
+ !per_cpu(hist_preemptirqsoff_counting, cpu)) {
+ per_cpu(hist_preemptirqsoff_counting, cpu) = 1;
+ if (!time_set)
+ start = ftrace_now(cpu);
+ per_cpu(hist_preemptirqsoff_start, cpu) = start;
+ }
+#endif
+ } else {
+ cycle_t uninitialized_var(stop);
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ if ((reason == IRQS_ON || reason == TRACE_STOP) &&
+ per_cpu(hist_irqsoff_counting, cpu)) {
+ cycle_t start = per_cpu(hist_irqsoff_start, cpu);
+
+ stop = ftrace_now(cpu);
+ time_set++;
+ if (start) {
+ long latency = ((long) (stop - start)) /
+ NSECS_PER_USECS;
+
+ latency_hist(IRQSOFF_LATENCY, cpu, latency, 0,
+ stop, NULL);
+ }
+ per_cpu(hist_irqsoff_counting, cpu) = 0;
+ }
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ if ((reason == PREEMPT_ON || reason == TRACE_STOP) &&
+ per_cpu(hist_preemptoff_counting, cpu)) {
+ cycle_t start = per_cpu(hist_preemptoff_start, cpu);
+
+ if (!(time_set++))
+ stop = ftrace_now(cpu);
+ if (start) {
+ long latency = ((long) (stop - start)) /
+ NSECS_PER_USECS;
+
+ latency_hist(PREEMPTOFF_LATENCY, cpu, latency,
+ 0, stop, NULL);
+ }
+ per_cpu(hist_preemptoff_counting, cpu) = 0;
+ }
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ if ((!per_cpu(hist_irqsoff_counting, cpu) ||
+ !per_cpu(hist_preemptoff_counting, cpu)) &&
+ per_cpu(hist_preemptirqsoff_counting, cpu)) {
+ cycle_t start = per_cpu(hist_preemptirqsoff_start, cpu);
+
+ if (!time_set)
+ stop = ftrace_now(cpu);
+ if (start) {
+ long latency = ((long) (stop - start)) /
+ NSECS_PER_USECS;
+
+ latency_hist(PREEMPTIRQSOFF_LATENCY, cpu,
+ latency, 0, stop, NULL);
+ }
+ per_cpu(hist_preemptirqsoff_counting, cpu) = 0;
+ }
+#endif
+ }
+}
+#endif
+
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+static DEFINE_RAW_SPINLOCK(wakeup_lock);
+static notrace void probe_sched_migrate_task(void *v, struct task_struct *task,
+ int cpu)
+{
+ int old_cpu = task_cpu(task);
+
+ if (cpu != old_cpu) {
+ unsigned long flags;
+ struct task_struct *cpu_wakeup_task;
+
+ raw_spin_lock_irqsave(&wakeup_lock, flags);
+
+ cpu_wakeup_task = per_cpu(wakeup_task, old_cpu);
+ if (task == cpu_wakeup_task) {
+ put_task_struct(cpu_wakeup_task);
+ per_cpu(wakeup_task, old_cpu) = NULL;
+ cpu_wakeup_task = per_cpu(wakeup_task, cpu) = task;
+ get_task_struct(cpu_wakeup_task);
+ }
+
+ raw_spin_unlock_irqrestore(&wakeup_lock, flags);
+ }
+}
+
+static notrace void probe_wakeup_latency_hist_start(void *v,
+ struct task_struct *p, int success)
+{
+ unsigned long flags;
+ struct task_struct *curr = current;
+ int cpu = task_cpu(p);
+ struct task_struct *cpu_wakeup_task;
+
+ raw_spin_lock_irqsave(&wakeup_lock, flags);
+
+ cpu_wakeup_task = per_cpu(wakeup_task, cpu);
+
+ if (wakeup_pid) {
+ if ((cpu_wakeup_task && p->prio == cpu_wakeup_task->prio) ||
+ p->prio == curr->prio)
+ per_cpu(wakeup_sharedprio, cpu) = 1;
+ if (likely(wakeup_pid != task_pid_nr(p)))
+ goto out;
+ } else {
+ if (likely(!rt_task(p)) ||
+ (cpu_wakeup_task && p->prio > cpu_wakeup_task->prio) ||
+ p->prio > curr->prio)
+ goto out;
+ if ((cpu_wakeup_task && p->prio == cpu_wakeup_task->prio) ||
+ p->prio == curr->prio)
+ per_cpu(wakeup_sharedprio, cpu) = 1;
+ }
+
+ if (cpu_wakeup_task)
+ put_task_struct(cpu_wakeup_task);
+ cpu_wakeup_task = per_cpu(wakeup_task, cpu) = p;
+ get_task_struct(cpu_wakeup_task);
+ cpu_wakeup_task->preempt_timestamp_hist =
+ ftrace_now(raw_smp_processor_id());
+out:
+ raw_spin_unlock_irqrestore(&wakeup_lock, flags);
+}
+
+static notrace void probe_wakeup_latency_hist_stop(void *v,
+ struct task_struct *prev, struct task_struct *next)
+{
+ unsigned long flags;
+ int cpu = task_cpu(next);
+ long latency;
+ cycle_t stop;
+ struct task_struct *cpu_wakeup_task;
+
+ raw_spin_lock_irqsave(&wakeup_lock, flags);
+
+ cpu_wakeup_task = per_cpu(wakeup_task, cpu);
+
+ if (cpu_wakeup_task == NULL)
+ goto out;
+
+ /* Already running? */
+ if (unlikely(current == cpu_wakeup_task))
+ goto out_reset;
+
+ if (next != cpu_wakeup_task) {
+ if (next->prio < cpu_wakeup_task->prio)
+ goto out_reset;
+
+ if (next->prio == cpu_wakeup_task->prio)
+ per_cpu(wakeup_sharedprio, cpu) = 1;
+
+ goto out;
+ }
+
+ if (current->prio == cpu_wakeup_task->prio)
+ per_cpu(wakeup_sharedprio, cpu) = 1;
+
+ /*
+ * The task we are waiting for is about to be switched to.
+ * Calculate latency and store it in histogram.
+ */
+ stop = ftrace_now(raw_smp_processor_id());
+
+ latency = ((long) (stop - next->preempt_timestamp_hist)) /
+ NSECS_PER_USECS;
+
+ if (per_cpu(wakeup_sharedprio, cpu)) {
+ latency_hist(WAKEUP_LATENCY_SHAREDPRIO, cpu, latency, 0, stop,
+ next);
+ per_cpu(wakeup_sharedprio, cpu) = 0;
+ } else {
+ latency_hist(WAKEUP_LATENCY, cpu, latency, 0, stop, next);
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ if (timerandwakeup_enabled_data.enabled) {
+ latency_hist(TIMERANDWAKEUP_LATENCY, cpu,
+ next->timer_offset + latency, next->timer_offset,
+ stop, next);
+ }
+#endif
+ }
+
+out_reset:
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ next->timer_offset = 0;
+#endif
+ put_task_struct(cpu_wakeup_task);
+ per_cpu(wakeup_task, cpu) = NULL;
+out:
+ raw_spin_unlock_irqrestore(&wakeup_lock, flags);
+}
+#endif
+
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+static notrace void probe_hrtimer_interrupt(void *v, int cpu,
+ long long latency_ns, struct task_struct *curr,
+ struct task_struct *task)
+{
+ if (latency_ns <= 0 && task != NULL && rt_task(task) &&
+ (task->prio < curr->prio ||
+ (task->prio == curr->prio &&
+ !cpumask_test_cpu(cpu, &task->cpus_allowed)))) {
+ long latency;
+ cycle_t now;
+
+ if (missed_timer_offsets_pid) {
+ if (likely(missed_timer_offsets_pid !=
+ task_pid_nr(task)))
+ return;
+ }
+
+ now = ftrace_now(cpu);
+ latency = (long) div_s64(-latency_ns, NSECS_PER_USECS);
+ latency_hist(MISSED_TIMER_OFFSETS, cpu, latency, latency, now,
+ task);
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ task->timer_offset = latency;
+#endif
+ }
+}
+#endif
+
+static __init int latency_hist_init(void)
+{
+ struct dentry *latency_hist_root = NULL;
+ struct dentry *dentry;
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ struct dentry *dentry_sharedprio;
+#endif
+ struct dentry *entry;
+ struct dentry *enable_root;
+ int i = 0;
+ struct hist_data *my_hist;
+ char name[64];
+ char *cpufmt = "CPU%d";
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ char *cpufmt_maxlatproc = "max_latency-CPU%d";
+ struct maxlatproc_data *mp = NULL;
+#endif
+
+ dentry = tracing_init_dentry();
+ latency_hist_root = debugfs_create_dir(latency_hist_dir_root, dentry);
+ enable_root = debugfs_create_dir("enable", latency_hist_root);
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ dentry = debugfs_create_dir(irqsoff_hist_dir, latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(irqsoff_hist, i), &latency_hist_fops);
+ my_hist = &per_cpu(irqsoff_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+ }
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)IRQSOFF_LATENCY, &latency_hist_reset_fops);
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ dentry = debugfs_create_dir(preemptoff_hist_dir,
+ latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(preemptoff_hist, i), &latency_hist_fops);
+ my_hist = &per_cpu(preemptoff_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+ }
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)PREEMPTOFF_LATENCY, &latency_hist_reset_fops);
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ dentry = debugfs_create_dir(preemptirqsoff_hist_dir,
+ latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(preemptirqsoff_hist, i), &latency_hist_fops);
+ my_hist = &per_cpu(preemptirqsoff_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+ }
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)PREEMPTIRQSOFF_LATENCY, &latency_hist_reset_fops);
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+ entry = debugfs_create_file("preemptirqsoff", 0644,
+ enable_root, (void *)&preemptirqsoff_enabled_data,
+ &enable_fops);
+#endif
+
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ dentry = debugfs_create_dir(wakeup_latency_hist_dir,
+ latency_hist_root);
+ dentry_sharedprio = debugfs_create_dir(
+ wakeup_latency_hist_dir_sharedprio, dentry);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(wakeup_latency_hist, i),
+ &latency_hist_fops);
+ my_hist = &per_cpu(wakeup_latency_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+
+ entry = debugfs_create_file(name, 0444, dentry_sharedprio,
+ &per_cpu(wakeup_latency_hist_sharedprio, i),
+ &latency_hist_fops);
+ my_hist = &per_cpu(wakeup_latency_hist_sharedprio, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+
+ sprintf(name, cpufmt_maxlatproc, i);
+
+ mp = &per_cpu(wakeup_maxlatproc, i);
+ entry = debugfs_create_file(name, 0444, dentry, mp,
+ &maxlatproc_fops);
+ clear_maxlatprocdata(mp);
+
+ mp = &per_cpu(wakeup_maxlatproc_sharedprio, i);
+ entry = debugfs_create_file(name, 0444, dentry_sharedprio, mp,
+ &maxlatproc_fops);
+ clear_maxlatprocdata(mp);
+ }
+ entry = debugfs_create_file("pid", 0644, dentry,
+ (void *)&wakeup_pid, &pid_fops);
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)WAKEUP_LATENCY, &latency_hist_reset_fops);
+ entry = debugfs_create_file("reset", 0644, dentry_sharedprio,
+ (void *)WAKEUP_LATENCY_SHAREDPRIO, &latency_hist_reset_fops);
+ entry = debugfs_create_file("wakeup", 0644,
+ enable_root, (void *)&wakeup_latency_enabled_data,
+ &enable_fops);
+#endif
+
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ dentry = debugfs_create_dir(missed_timer_offsets_dir,
+ latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(missed_timer_offsets, i), &latency_hist_fops);
+ my_hist = &per_cpu(missed_timer_offsets, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+
+ sprintf(name, cpufmt_maxlatproc, i);
+ mp = &per_cpu(missed_timer_offsets_maxlatproc, i);
+ entry = debugfs_create_file(name, 0444, dentry, mp,
+ &maxlatproc_fops);
+ clear_maxlatprocdata(mp);
+ }
+ entry = debugfs_create_file("pid", 0644, dentry,
+ (void *)&missed_timer_offsets_pid, &pid_fops);
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)MISSED_TIMER_OFFSETS, &latency_hist_reset_fops);
+ entry = debugfs_create_file("missed_timer_offsets", 0644,
+ enable_root, (void *)&missed_timer_offsets_enabled_data,
+ &enable_fops);
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ dentry = debugfs_create_dir(timerandwakeup_latency_hist_dir,
+ latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(timerandwakeup_latency_hist, i),
+ &latency_hist_fops);
+ my_hist = &per_cpu(timerandwakeup_latency_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+
+ sprintf(name, cpufmt_maxlatproc, i);
+ mp = &per_cpu(timerandwakeup_maxlatproc, i);
+ entry = debugfs_create_file(name, 0444, dentry, mp,
+ &maxlatproc_fops);
+ clear_maxlatprocdata(mp);
+ }
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)TIMERANDWAKEUP_LATENCY, &latency_hist_reset_fops);
+ entry = debugfs_create_file("timerandwakeup", 0644,
+ enable_root, (void *)&timerandwakeup_enabled_data,
+ &enable_fops);
+#endif
+ return 0;
+}
+
+device_initcall(latency_hist_init);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 138077b..f9401ed 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -442,7 +442,7 @@ int __trace_puts(unsigned long ip, const char *str, int size)
local_save_flags(irq_flags);
buffer = global_trace.trace_buffer.buffer;
- event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
+ event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
irq_flags, preempt_count());
if (!event)
return 0;
@@ -1509,6 +1509,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
struct task_struct *tsk = current;
entry->preempt_count = pc & 0xff;
+ entry->preempt_lazy_count = preempt_lazy_count();
entry->pid = (tsk) ? tsk->pid : 0;
entry->flags =
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
@@ -1518,7 +1519,10 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
#endif
((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
- (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
+ (need_resched_now() ? TRACE_FLAG_NEED_RESCHED : 0) |
+ (need_resched_lazy() ? TRACE_FLAG_NEED_RESCHED_LAZY : 0);
+
+ entry->migrate_disable = (tsk) ? __migrate_disabled(tsk) & 0xFF : 0;
}
EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
@@ -2408,14 +2412,17 @@ get_total_entries(struct trace_buffer *buf,
static void print_lat_help_header(struct seq_file *m)
{
- seq_puts(m, "# _------=> CPU# \n");
- seq_puts(m, "# / _-----=> irqs-off \n");
- seq_puts(m, "# | / _----=> need-resched \n");
- seq_puts(m, "# || / _---=> hardirq/softirq \n");
- seq_puts(m, "# ||| / _--=> preempt-depth \n");
- seq_puts(m, "# |||| / delay \n");
- seq_puts(m, "# cmd pid ||||| time | caller \n");
- seq_puts(m, "# \\ / ||||| \\ | / \n");
+ seq_puts(m, "# _--------=> CPU# \n");
+ seq_puts(m, "# / _-------=> irqs-off \n");
+ seq_puts(m, "# | / _------=> need-resched \n");
+ seq_puts(m, "# || / _-----=> need-resched_lazy \n");
+ seq_puts(m, "# ||| / _----=> hardirq/softirq \n");
+ seq_puts(m, "# |||| / _---=> preempt-depth \n");
+ seq_puts(m, "# ||||| / _--=> preempt-lazy-depth\n");
+ seq_puts(m, "# |||||| / _-=> migrate-disable \n");
+ seq_puts(m, "# ||||||| / delay \n");
+ seq_puts(m, "# cmd pid |||||||| time | caller \n");
+ seq_puts(m, "# \\ / |||||||| \\ | / \n");
}
static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
@@ -2439,13 +2446,16 @@ static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m)
static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m)
{
print_event_info(buf, m);
- seq_puts(m, "# _-----=> irqs-off\n");
- seq_puts(m, "# / _----=> need-resched\n");
- seq_puts(m, "# | / _---=> hardirq/softirq\n");
- seq_puts(m, "# || / _--=> preempt-depth\n");
- seq_puts(m, "# ||| / delay\n");
- seq_puts(m, "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n");
- seq_puts(m, "# | | | |||| | |\n");
+ seq_puts(m, "# _-------=> irqs-off \n");
+ seq_puts(m, "# / _------=> need-resched \n");
+ seq_puts(m, "# |/ _-----=> need-resched_lazy \n");
+ seq_puts(m, "# ||/ _----=> hardirq/softirq \n");
+ seq_puts(m, "# |||/ _---=> preempt-depth \n");
+ seq_puts(m, "# ||||/ _--=> preempt-lazy-depth\n");
+ seq_puts(m, "# ||||| / _-=> migrate-disable \n");
+ seq_puts(m, "# |||||| / delay\n");
+ seq_puts(m, "# TASK-PID CPU# |||||| TIMESTAMP FUNCTION\n");
+ seq_puts(m, "# | | | |||||| | |\n");
}
void
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 10c86fb..109291a 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -117,6 +117,7 @@ struct kretprobe_trace_entry_head {
* NEED_RESCHED - reschedule is requested
* HARDIRQ - inside an interrupt handler
* SOFTIRQ - inside a softirq handler
+ * NEED_RESCHED_LAZY - lazy reschedule is requested
*/
enum trace_flag_type {
TRACE_FLAG_IRQS_OFF = 0x01,
@@ -124,6 +125,7 @@ enum trace_flag_type {
TRACE_FLAG_NEED_RESCHED = 0x04,
TRACE_FLAG_HARDIRQ = 0x08,
TRACE_FLAG_SOFTIRQ = 0x10,
+ TRACE_FLAG_NEED_RESCHED_LAZY = 0x20,
};
#define TRACE_BUF_SIZE 1024
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index bc1bd20..9e49f3f 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -160,6 +160,8 @@ static int trace_define_common_fields(void)
__common_field(unsigned char, flags);
__common_field(unsigned char, preempt_count);
__common_field(int, pid);
+ __common_field(unsigned short, migrate_disable);
+ __common_field(unsigned short, padding);
return ret;
}
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 2aefbee..2f4eb37 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -17,6 +17,7 @@
#include <linux/fs.h>
#include "trace.h"
+#include <trace/events/hist.h>
static struct trace_array *irqsoff_trace __read_mostly;
static int tracer_enabled __read_mostly;
@@ -439,11 +440,13 @@ void start_critical_timings(void)
{
if (preempt_trace() || irq_trace())
start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
+ trace_preemptirqsoff_hist(TRACE_START, 1);
}
EXPORT_SYMBOL_GPL(start_critical_timings);
void stop_critical_timings(void)
{
+ trace_preemptirqsoff_hist(TRACE_STOP, 0);
if (preempt_trace() || irq_trace())
stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}
@@ -453,6 +456,7 @@ EXPORT_SYMBOL_GPL(stop_critical_timings);
#ifdef CONFIG_PROVE_LOCKING
void time_hardirqs_on(unsigned long a0, unsigned long a1)
{
+ trace_preemptirqsoff_hist(IRQS_ON, 0);
if (!preempt_trace() && irq_trace())
stop_critical_timing(a0, a1);
}
@@ -461,6 +465,7 @@ void time_hardirqs_off(unsigned long a0, unsigned long a1)
{
if (!preempt_trace() && irq_trace())
start_critical_timing(a0, a1);
+ trace_preemptirqsoff_hist(IRQS_OFF, 1);
}
#else /* !CONFIG_PROVE_LOCKING */
@@ -486,6 +491,7 @@ inline void print_irqtrace_events(struct task_struct *curr)
*/
void trace_hardirqs_on(void)
{
+ trace_preemptirqsoff_hist(IRQS_ON, 0);
if (!preempt_trace() && irq_trace())
stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}
@@ -495,11 +501,13 @@ void trace_hardirqs_off(void)
{
if (!preempt_trace() && irq_trace())
start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
+ trace_preemptirqsoff_hist(IRQS_OFF, 1);
}
EXPORT_SYMBOL(trace_hardirqs_off);
void trace_hardirqs_on_caller(unsigned long caller_addr)
{
+ trace_preemptirqsoff_hist(IRQS_ON, 0);
if (!preempt_trace() && irq_trace())
stop_critical_timing(CALLER_ADDR0, caller_addr);
}
@@ -509,6 +517,7 @@ void trace_hardirqs_off_caller(unsigned long caller_addr)
{
if (!preempt_trace() && irq_trace())
start_critical_timing(CALLER_ADDR0, caller_addr);
+ trace_preemptirqsoff_hist(IRQS_OFF, 1);
}
EXPORT_SYMBOL(trace_hardirqs_off_caller);
@@ -518,12 +527,14 @@ EXPORT_SYMBOL(trace_hardirqs_off_caller);
#ifdef CONFIG_PREEMPT_TRACER
void trace_preempt_on(unsigned long a0, unsigned long a1)
{
+ trace_preemptirqsoff_hist(PREEMPT_ON, 0);
if (preempt_trace() && !irq_trace())
stop_critical_timing(a0, a1);
}
void trace_preempt_off(unsigned long a0, unsigned long a1)
{
+ trace_preemptirqsoff_hist(PREEMPT_ON, 1);
if (preempt_trace() && !irq_trace())
start_critical_timing(a0, a1);
}
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 34e7cba..46b6467 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -606,6 +606,7 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
{
char hardsoft_irq;
char need_resched;
+ char need_resched_lazy;
char irqs_off;
int hardirq;
int softirq;
@@ -620,14 +621,17 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
'.';
need_resched =
(entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.';
+ need_resched_lazy =
+ (entry->flags & TRACE_FLAG_NEED_RESCHED_LAZY) ? 'L' : '.';
hardsoft_irq =
(hardirq && softirq) ? 'H' :
hardirq ? 'h' :
softirq ? 's' :
'.';
- if (!trace_seq_printf(s, "%c%c%c",
- irqs_off, need_resched, hardsoft_irq))
+ if (!trace_seq_printf(s, "%c%c%c%c",
+ irqs_off, need_resched, need_resched_lazy,
+ hardsoft_irq))
return 0;
if (entry->preempt_count)
@@ -635,6 +639,16 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
else
ret = trace_seq_putc(s, '.');
+ if (entry->preempt_lazy_count)
+ ret = trace_seq_printf(s, "%x", entry->preempt_lazy_count);
+ else
+ ret = trace_seq_putc(s, '.');
+
+ if (entry->migrate_disable)
+ ret = trace_seq_printf(s, "%x", entry->migrate_disable);
+ else
+ ret = trace_seq_putc(s, '.');
+
return ret;
}
diff --git a/kernel/user.c b/kernel/user.c
index 5bbb919..2800008 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -154,11 +154,11 @@ void free_uid(struct user_struct *up)
if (!up)
return;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (atomic_dec_and_lock(&up->__count, &uidhash_lock))
free_user(up, flags);
else
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
struct user_struct *alloc_uid(kuid_t uid)
diff --git a/kernel/wait-simple.c b/kernel/wait-simple.c
new file mode 100644
index 0000000..7dfa86d
--- /dev/null
+++ b/kernel/wait-simple.c
@@ -0,0 +1,115 @@
+/*
+ * Simple waitqueues without fancy flags and callbacks
+ *
+ * (C) 2011 Thomas Gleixner <tglx@linutronix.de>
+ *
+ * Based on kernel/wait.c
+ *
+ * For licencing details see kernel-base/COPYING
+ */
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/wait-simple.h>
+
+/* Adds w to head->list. Must be called with head->lock locked. */
+static inline void __swait_enqueue(struct swait_head *head, struct swaiter *w)
+{
+ list_add(&w->node, &head->list);
+ /* We can't let the condition leak before the setting of head */
+ smp_mb();
+}
+
+/* Removes w from head->list. Must be called with head->lock locked. */
+static inline void __swait_dequeue(struct swaiter *w)
+{
+ list_del_init(&w->node);
+}
+
+void __init_swait_head(struct swait_head *head, struct lock_class_key *key)
+{
+ raw_spin_lock_init(&head->lock);
+ lockdep_set_class(&head->lock, key);
+ INIT_LIST_HEAD(&head->list);
+}
+EXPORT_SYMBOL(__init_swait_head);
+
+void swait_prepare_locked(struct swait_head *head, struct swaiter *w)
+{
+ w->task = current;
+ if (list_empty(&w->node))
+ __swait_enqueue(head, w);
+}
+
+void swait_prepare(struct swait_head *head, struct swaiter *w, int state)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&head->lock, flags);
+ swait_prepare_locked(head, w);
+ __set_current_state(state);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
+}
+EXPORT_SYMBOL(swait_prepare);
+
+void swait_finish_locked(struct swait_head *head, struct swaiter *w)
+{
+ __set_current_state(TASK_RUNNING);
+ if (w->task)
+ __swait_dequeue(w);
+}
+
+void swait_finish(struct swait_head *head, struct swaiter *w)
+{
+ unsigned long flags;
+
+ __set_current_state(TASK_RUNNING);
+ if (w->task) {
+ raw_spin_lock_irqsave(&head->lock, flags);
+ __swait_dequeue(w);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
+ }
+}
+EXPORT_SYMBOL(swait_finish);
+
+unsigned int
+__swait_wake_locked(struct swait_head *head, unsigned int state, unsigned int num)
+{
+ struct swaiter *curr, *next;
+ int woken = 0;
+
+ list_for_each_entry_safe(curr, next, &head->list, node) {
+ if (wake_up_state(curr->task, state)) {
+ __swait_dequeue(curr);
+ /*
+ * The waiting task can free the waiter as
+ * soon as curr->task = NULL is written,
+ * without taking any locks. A memory barrier
+ * is required here to prevent the following
+ * store to curr->task from getting ahead of
+ * the dequeue operation.
+ */
+ smp_wmb();
+ curr->task = NULL;
+ if (++woken == num)
+ break;
+ }
+ }
+ return woken;
+}
+
+unsigned int
+__swait_wake(struct swait_head *head, unsigned int state, unsigned int num)
+{
+ unsigned long flags;
+ int woken;
+
+ if (!swaitqueue_active(head))
+ return 0;
+
+ raw_spin_lock_irqsave(&head->lock, flags);
+ woken = __swait_wake_locked(head, state, num);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
+ return woken;
+}
+EXPORT_SYMBOL(__swait_wake);
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 4431610..870b748 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -205,6 +205,8 @@ static int is_softlockup(unsigned long touch_ts)
#ifdef CONFIG_HARDLOCKUP_DETECTOR
+static DEFINE_RAW_SPINLOCK(watchdog_output_lock);
+
static struct perf_event_attr wd_hw_attr = {
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
@@ -239,10 +241,19 @@ static void watchdog_overflow_callback(struct perf_event *event,
if (__this_cpu_read(hard_watchdog_warn) == true)
return;
- if (hardlockup_panic)
+ /*
+ * If early-printk is enabled then make sure we do not
+ * lock up in printk() and kill console logging:
+ */
+ printk_kill();
+
+ if (hardlockup_panic) {
panic("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
- else
+ } else {
+ raw_spin_lock(&watchdog_output_lock);
WARN(1, "Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+ raw_spin_unlock(&watchdog_output_lock);
+ }
__this_cpu_write(hard_watchdog_warn, true);
return;
@@ -346,6 +357,7 @@ static void watchdog_enable(unsigned int cpu)
/* kick off the timer for the hardlockup detector */
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = watchdog_timer_fn;
+ hrtimer->irqsafe = 1;
/* Enable the perf event */
watchdog_nmi_enable(cpu);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 60fee69..9efb7ce 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -48,6 +48,8 @@
#include <linux/nodemask.h>
#include <linux/moduleparam.h>
#include <linux/uaccess.h>
+#include <linux/locallock.h>
+#include <linux/delay.h>
#include "workqueue_internal.h"
@@ -129,11 +131,11 @@ enum {
*
* PL: wq_pool_mutex protected.
*
- * PR: wq_pool_mutex protected for writes. Sched-RCU protected for reads.
+ * PR: wq_pool_mutex protected for writes. RCU protected for reads.
*
* WQ: wq->mutex protected.
*
- * WR: wq->mutex protected for writes. Sched-RCU protected for reads.
+ * WR: wq->mutex protected for writes. RCU protected for reads.
*
* MD: wq_mayday_lock protected.
*/
@@ -178,7 +180,7 @@ struct worker_pool {
atomic_t nr_running ____cacheline_aligned_in_smp;
/*
- * Destruction of pool is sched-RCU protected to allow dereferences
+ * Destruction of pool is RCU protected to allow dereferences
* from get_work_pool().
*/
struct rcu_head rcu;
@@ -207,7 +209,7 @@ struct pool_workqueue {
/*
* Release of unbound pwq is punted to system_wq. See put_pwq()
* and pwq_unbound_release_workfn() for details. pool_workqueue
- * itself is also sched-RCU protected so that the first pwq can be
+ * itself is also RCU protected so that the first pwq can be
* determined without grabbing wq->mutex.
*/
struct work_struct unbound_release_work;
@@ -323,6 +325,8 @@ EXPORT_SYMBOL_GPL(system_power_efficient_wq);
struct workqueue_struct *system_freezable_power_efficient_wq __read_mostly;
EXPORT_SYMBOL_GPL(system_freezable_power_efficient_wq);
+static DEFINE_LOCAL_IRQ_LOCK(pendingb_lock);
+
static int worker_thread(void *__worker);
static void copy_workqueue_attrs(struct workqueue_attrs *to,
const struct workqueue_attrs *from);
@@ -331,14 +335,14 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to,
#include <trace/events/workqueue.h>
#define assert_rcu_or_pool_mutex() \
- rcu_lockdep_assert(rcu_read_lock_sched_held() || \
+ rcu_lockdep_assert(rcu_read_lock_held() || \
lockdep_is_held(&wq_pool_mutex), \
- "sched RCU or wq_pool_mutex should be held")
+ "RCU or wq_pool_mutex should be held")
#define assert_rcu_or_wq_mutex(wq) \
- rcu_lockdep_assert(rcu_read_lock_sched_held() || \
+ rcu_lockdep_assert(rcu_read_lock_held() || \
lockdep_is_held(&wq->mutex), \
- "sched RCU or wq->mutex should be held")
+ "RCU or wq->mutex should be held")
#ifdef CONFIG_LOCKDEP
#define assert_manager_or_pool_lock(pool) \
@@ -360,7 +364,7 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to,
* @pool: iteration cursor
* @pi: integer used for iteration
*
- * This must be called either with wq_pool_mutex held or sched RCU read
+ * This must be called either with wq_pool_mutex held or RCU read
* locked. If the pool needs to be used beyond the locking in effect, the
* caller is responsible for guaranteeing that the pool stays online.
*
@@ -393,7 +397,7 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to,
* @pwq: iteration cursor
* @wq: the target workqueue
*
- * This must be called either with wq->mutex held or sched RCU read locked.
+ * This must be called either with wq->mutex held or RCU read locked.
* If the pwq needs to be used beyond the locking in effect, the caller is
* responsible for guaranteeing that the pwq stays online.
*
@@ -541,7 +545,7 @@ static int worker_pool_assign_id(struct worker_pool *pool)
* @wq: the target workqueue
* @node: the node ID
*
- * This must be called either with pwq_lock held or sched RCU read locked.
+ * This must be called either with pwq_lock held or RCU read locked.
* If the pwq needs to be used beyond the locking in effect, the caller is
* responsible for guaranteeing that the pwq stays online.
*
@@ -645,8 +649,8 @@ static struct pool_workqueue *get_work_pwq(struct work_struct *work)
* @work: the work item of interest
*
* Pools are created and destroyed under wq_pool_mutex, and allows read
- * access under sched-RCU read lock. As such, this function should be
- * called under wq_pool_mutex or with preemption disabled.
+ * access under RCU read lock. As such, this function should be
+ * called under wq_pool_mutex or inside of a rcu_read_lock() region.
*
* All fields of the returned pool are accessible as long as the above
* mentioned locking is in effect. If the returned pool needs to be used
@@ -804,44 +808,31 @@ static void wake_up_worker(struct worker_pool *pool)
}
/**
- * wq_worker_waking_up - a worker is waking up
- * @task: task waking up
- * @cpu: CPU @task is waking up to
- *
- * This function is called during try_to_wake_up() when a worker is
- * being awoken.
+ * wq_worker_running - a worker is running again
+ * @task: task returning from sleep
*
- * CONTEXT:
- * spin_lock_irq(rq->lock)
+ * This function is called when a worker returns from schedule()
*/
-void wq_worker_waking_up(struct task_struct *task, int cpu)
+void wq_worker_running(struct task_struct *task)
{
struct worker *worker = kthread_data(task);
- if (!(worker->flags & WORKER_NOT_RUNNING)) {
- WARN_ON_ONCE(worker->pool->cpu != cpu);
+ if (!worker->sleeping)
+ return;
+ if (!(worker->flags & WORKER_NOT_RUNNING))
atomic_inc(&worker->pool->nr_running);
- }
+ worker->sleeping = 0;
}
/**
* wq_worker_sleeping - a worker is going to sleep
* @task: task going to sleep
- * @cpu: CPU in question, must be the current CPU number
- *
- * This function is called during schedule() when a busy worker is
- * going to sleep. Worker on the same cpu can be woken up by
- * returning pointer to its task.
- *
- * CONTEXT:
- * spin_lock_irq(rq->lock)
- *
- * Return:
- * Worker task on @cpu to wake up, %NULL if none.
+ * This function is called from schedule() when a busy worker is
+ * going to sleep.
*/
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
+void wq_worker_sleeping(struct task_struct *task)
{
- struct worker *worker = kthread_data(task), *to_wakeup = NULL;
+ struct worker *next, *worker = kthread_data(task);
struct worker_pool *pool;
/*
@@ -850,14 +841,15 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
* checking NOT_RUNNING.
*/
if (worker->flags & WORKER_NOT_RUNNING)
- return NULL;
+ return;
pool = worker->pool;
- /* this can only happen on the local cpu */
- if (WARN_ON_ONCE(cpu != raw_smp_processor_id()))
- return NULL;
+ if (WARN_ON_ONCE(worker->sleeping))
+ return;
+ worker->sleeping = 1;
+ spin_lock_irq(&pool->lock);
/*
* The counterpart of the following dec_and_test, implied mb,
* worklist not empty test sequence is in insert_work().
@@ -870,9 +862,12 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
* lock is safe.
*/
if (atomic_dec_and_test(&pool->nr_running) &&
- !list_empty(&pool->worklist))
- to_wakeup = first_worker(pool);
- return to_wakeup ? to_wakeup->task : NULL;
+ !list_empty(&pool->worklist)) {
+ next = first_worker(pool);
+ if (next)
+ wake_up_process(next->task);
+ }
+ spin_unlock_irq(&pool->lock);
}
/**
@@ -1079,12 +1074,12 @@ static void put_pwq_unlocked(struct pool_workqueue *pwq)
{
if (pwq) {
/*
- * As both pwqs and pools are sched-RCU protected, the
+ * As both pwqs and pools are RCU protected, the
* following lock operations are safe.
*/
- spin_lock_irq(&pwq->pool->lock);
+ local_spin_lock_irq(pendingb_lock, &pwq->pool->lock);
put_pwq(pwq);
- spin_unlock_irq(&pwq->pool->lock);
+ local_spin_unlock_irq(pendingb_lock, &pwq->pool->lock);
}
}
@@ -1186,7 +1181,7 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
struct worker_pool *pool;
struct pool_workqueue *pwq;
- local_irq_save(*flags);
+ local_lock_irqsave(pendingb_lock, *flags);
/* try to steal the timer if it exists */
if (is_dwork) {
@@ -1205,6 +1200,7 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)))
return 0;
+ rcu_read_lock();
/*
* The queueing is in progress, or it is already queued. Try to
* steal it from ->worklist without clearing WORK_STRUCT_PENDING.
@@ -1243,14 +1239,16 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
set_work_pool_and_keep_pending(work, pool->id);
spin_unlock(&pool->lock);
+ rcu_read_unlock();
return 1;
}
spin_unlock(&pool->lock);
fail:
- local_irq_restore(*flags);
+ rcu_read_unlock();
+ local_unlock_irqrestore(pendingb_lock, *flags);
if (work_is_canceling(work))
return -ENOENT;
- cpu_relax();
+ cpu_chill();
return -EAGAIN;
}
@@ -1319,7 +1317,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq,
* queued or lose PENDING. Grabbing PENDING and queueing should
* happen with IRQ disabled.
*/
- WARN_ON_ONCE(!irqs_disabled());
+ WARN_ON_ONCE_NONRT(!irqs_disabled());
debug_work_activate(work);
@@ -1327,6 +1325,8 @@ static void __queue_work(int cpu, struct workqueue_struct *wq,
if (unlikely(wq->flags & __WQ_DRAINING) &&
WARN_ON_ONCE(!is_chained_work(wq)))
return;
+
+ rcu_read_lock();
retry:
if (req_cpu == WORK_CPU_UNBOUND)
cpu = raw_smp_processor_id();
@@ -1383,10 +1383,8 @@ retry:
/* pwq determined, queue */
trace_workqueue_queue_work(req_cpu, pwq, work);
- if (WARN_ON(!list_empty(&work->entry))) {
- spin_unlock(&pwq->pool->lock);
- return;
- }
+ if (WARN_ON(!list_empty(&work->entry)))
+ goto out;
pwq->nr_in_flight[pwq->work_color]++;
work_flags = work_color_to_flags(pwq->work_color);
@@ -1402,7 +1400,9 @@ retry:
insert_work(pwq, work, worklist, work_flags);
+out:
spin_unlock(&pwq->pool->lock);
+ rcu_read_unlock();
}
/**
@@ -1422,14 +1422,14 @@ bool queue_work_on(int cpu, struct workqueue_struct *wq,
bool ret = false;
unsigned long flags;
- local_irq_save(flags);
+ local_lock_irqsave(pendingb_lock,flags);
if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
__queue_work(cpu, wq, work);
ret = true;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
return ret;
}
EXPORT_SYMBOL(queue_work_on);
@@ -1496,14 +1496,14 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
unsigned long flags;
/* read the comment in __queue_work() */
- local_irq_save(flags);
+ local_lock_irqsave(pendingb_lock, flags);
if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
__queue_delayed_work(cpu, wq, dwork, delay);
ret = true;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
return ret;
}
EXPORT_SYMBOL(queue_delayed_work_on);
@@ -1538,7 +1538,7 @@ bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
if (likely(ret >= 0)) {
__queue_delayed_work(cpu, wq, dwork, delay);
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
}
/* -ENOENT from try_to_grab_pending() becomes %true */
@@ -2809,14 +2809,14 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr)
might_sleep();
- local_irq_disable();
+ rcu_read_lock();
pool = get_work_pool(work);
if (!pool) {
- local_irq_enable();
+ rcu_read_unlock();
return false;
}
- spin_lock(&pool->lock);
+ spin_lock_irq(&pool->lock);
/* see the comment in try_to_grab_pending() with the same code */
pwq = get_work_pwq(work);
if (pwq) {
@@ -2843,10 +2843,11 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr)
else
lock_map_acquire_read(&pwq->wq->lockdep_map);
lock_map_release(&pwq->wq->lockdep_map);
-
+ rcu_read_unlock();
return true;
already_gone:
spin_unlock_irq(&pool->lock);
+ rcu_read_unlock();
return false;
}
@@ -2900,7 +2901,7 @@ static bool __cancel_work_timer(struct work_struct *work, bool is_dwork)
/* tell other tasks trying to grab @work to back off */
mark_work_canceling(work);
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
flush_work(work);
clear_work_data(work);
@@ -2945,10 +2946,10 @@ EXPORT_SYMBOL_GPL(cancel_work_sync);
*/
bool flush_delayed_work(struct delayed_work *dwork)
{
- local_irq_disable();
+ local_lock_irq(pendingb_lock);
if (del_timer_sync(&dwork->timer))
__queue_work(dwork->cpu, dwork->wq, &dwork->work);
- local_irq_enable();
+ local_unlock_irq(pendingb_lock);
return flush_work(&dwork->work);
}
EXPORT_SYMBOL(flush_delayed_work);
@@ -2983,7 +2984,7 @@ bool cancel_delayed_work(struct delayed_work *dwork)
set_work_pool_and_clear_pending(&dwork->work,
get_work_pool_id(&dwork->work));
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
return ret;
}
EXPORT_SYMBOL(cancel_delayed_work);
@@ -3169,7 +3170,8 @@ static ssize_t wq_pool_ids_show(struct device *dev,
const char *delim = "";
int node, written = 0;
- rcu_read_lock_sched();
+ get_online_cpus();
+ rcu_read_lock();
for_each_node(node) {
written += scnprintf(buf + written, PAGE_SIZE - written,
"%s%d:%d", delim, node,
@@ -3177,7 +3179,8 @@ static ssize_t wq_pool_ids_show(struct device *dev,
delim = " ";
}
written += scnprintf(buf + written, PAGE_SIZE - written, "\n");
- rcu_read_unlock_sched();
+ rcu_read_unlock();
+ put_online_cpus();
return written;
}
@@ -3543,7 +3546,7 @@ static void rcu_free_pool(struct rcu_head *rcu)
* put_unbound_pool - put a worker_pool
* @pool: worker_pool to put
*
- * Put @pool. If its refcnt reaches zero, it gets destroyed in sched-RCU
+ * Put @pool. If its refcnt reaches zero, it gets destroyed in RCU
* safe manner. get_unbound_pool() calls this function on its failure path
* and this function should be able to release pools which went through,
* successfully or not, init_worker_pool().
@@ -3590,8 +3593,8 @@ static void put_unbound_pool(struct worker_pool *pool)
del_timer_sync(&pool->idle_timer);
del_timer_sync(&pool->mayday_timer);
- /* sched-RCU protected to allow dereferences from get_work_pool() */
- call_rcu_sched(&pool->rcu, rcu_free_pool);
+ /* RCU protected to allow dereferences from get_work_pool() */
+ call_rcu(&pool->rcu, rcu_free_pool);
}
/**
@@ -3704,7 +3707,7 @@ static void pwq_unbound_release_workfn(struct work_struct *work)
put_unbound_pool(pool);
mutex_unlock(&wq_pool_mutex);
- call_rcu_sched(&pwq->rcu, rcu_free_pwq);
+ call_rcu(&pwq->rcu, rcu_free_pwq);
/*
* If we're the last pwq going away, @wq is already dead and no one
@@ -4417,7 +4420,8 @@ bool workqueue_congested(int cpu, struct workqueue_struct *wq)
struct pool_workqueue *pwq;
bool ret;
- rcu_read_lock_sched();
+ rcu_read_lock();
+ preempt_disable();
if (cpu == WORK_CPU_UNBOUND)
cpu = smp_processor_id();
@@ -4428,7 +4432,8 @@ bool workqueue_congested(int cpu, struct workqueue_struct *wq)
pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu));
ret = !list_empty(&pwq->delayed_works);
- rcu_read_unlock_sched();
+ preempt_enable();
+ rcu_read_unlock();
return ret;
}
@@ -4454,16 +4459,15 @@ unsigned int work_busy(struct work_struct *work)
if (work_pending(work))
ret |= WORK_BUSY_PENDING;
- local_irq_save(flags);
+ rcu_read_lock();
pool = get_work_pool(work);
if (pool) {
- spin_lock(&pool->lock);
+ spin_lock_irqsave(&pool->lock, flags);
if (find_worker_executing_work(pool, work))
ret |= WORK_BUSY_RUNNING;
- spin_unlock(&pool->lock);
+ spin_unlock_irqrestore(&pool->lock, flags);
}
- local_irq_restore(flags);
-
+ rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(work_busy);
@@ -4916,16 +4920,16 @@ bool freeze_workqueues_busy(void)
* nr_active is monotonically decreasing. It's safe
* to peek without lock.
*/
- rcu_read_lock_sched();
+ rcu_read_lock();
for_each_pwq(pwq, wq) {
WARN_ON_ONCE(pwq->nr_active < 0);
if (pwq->nr_active) {
busy = true;
- rcu_read_unlock_sched();
+ rcu_read_unlock();
goto out_unlock;
}
}
- rcu_read_unlock_sched();
+ rcu_read_unlock();
}
out_unlock:
mutex_unlock(&wq_pool_mutex);
diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h
index 7e2204d..2bb5b5a 100644
--- a/kernel/workqueue_internal.h
+++ b/kernel/workqueue_internal.h
@@ -41,6 +41,7 @@ struct worker {
unsigned long last_active; /* L: last active timestamp */
unsigned int flags; /* X: flags */
int id; /* I: worker id */
+ int sleeping; /* None */
/*
* Opaque string set with work_set_desc(). Printed out with task
@@ -66,7 +67,7 @@ static inline struct worker *current_wq_worker(void)
* Scheduler hooks for concurrency managed workqueue. Only to be used from
* sched/core.c and workqueue.c.
*/
-void wq_worker_waking_up(struct task_struct *task, int cpu);
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu);
+void wq_worker_running(struct task_struct *task);
+void wq_worker_sleeping(struct task_struct *task);
#endif /* _KERNEL_WORKQUEUE_INTERNAL_H */
diff --git a/lib/Kconfig b/lib/Kconfig
index 2479a69..4490089 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -57,6 +57,7 @@ config CMPXCHG_LOCKREF
depends on !GENERIC_LOCKBREAK
depends on !DEBUG_SPINLOCK
depends on !DEBUG_LOCK_ALLOC
+ depends on !PREEMPT_RT_BASE
config CRC_CCITT
tristate "CRC-CCITT functions"
@@ -350,6 +351,7 @@ config CHECK_SIGNATURE
config CPUMASK_OFFSTACK
bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
+ depends on !PREEMPT_RT_FULL
help
Use dynamic allocation for cpumask_var_t, instead of putting
them on the stack. This is a bit more expensive, but avoids
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 094f315..bde5dd2 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -597,7 +597,7 @@ endmenu # "Memory Debugging"
config DEBUG_SHIRQ
bool "Debug shared IRQ handlers"
- depends on DEBUG_KERNEL
+ depends on DEBUG_KERNEL && !PREEMPT_RT_BASE
help
Enable this to generate a spurious interrupt as soon as a shared
interrupt handler is registered, and just before one is deregistered.
diff --git a/lib/Makefile b/lib/Makefile
index d7ce91e..6e23a0f 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -43,8 +43,11 @@ obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o
obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o
obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
+
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
+endif
lib-$(CONFIG_PERCPU_RWSEM) += percpu-rwsem.o
GCOV_PROFILE_hweight.o := n
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index bf2c8b1..1ac2049 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -308,7 +308,10 @@ __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
struct debug_obj *obj;
unsigned long flags;
- fill_pool();
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (preempt_count() == 0 && !irqs_disabled())
+#endif
+ fill_pool();
db = get_bucket((unsigned long) addr);
diff --git a/lib/idr.c b/lib/idr.c
index bfe4db4..ae69d32 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -37,6 +37,7 @@
#include <linux/spinlock.h>
#include <linux/percpu.h>
#include <linux/hardirq.h>
+#include <linux/locallock.h>
#define MAX_IDR_SHIFT (sizeof(int) * 8 - 1)
#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT)
@@ -389,6 +390,36 @@ int __idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id)
}
EXPORT_SYMBOL(__idr_get_new_above);
+#ifdef CONFIG_PREEMPT_RT_FULL
+static DEFINE_LOCAL_IRQ_LOCK(idr_lock);
+
+static inline void idr_preload_lock(void)
+{
+ local_lock(idr_lock);
+}
+
+static inline void idr_preload_unlock(void)
+{
+ local_unlock(idr_lock);
+}
+
+void idr_preload_end(void)
+{
+ idr_preload_unlock();
+}
+EXPORT_SYMBOL(idr_preload_end);
+#else
+static inline void idr_preload_lock(void)
+{
+ preempt_disable();
+}
+
+static inline void idr_preload_unlock(void)
+{
+ preempt_enable();
+}
+#endif
+
/**
* idr_preload - preload for idr_alloc()
* @gfp_mask: allocation mask to use for preloading
@@ -423,7 +454,7 @@ void idr_preload(gfp_t gfp_mask)
WARN_ON_ONCE(in_interrupt());
might_sleep_if(gfp_mask & __GFP_WAIT);
- preempt_disable();
+ idr_preload_lock();
/*
* idr_alloc() is likely to succeed w/o full idr_layer buffer and
@@ -435,9 +466,9 @@ void idr_preload(gfp_t gfp_mask)
while (__this_cpu_read(idr_preload_cnt) < MAX_IDR_FREE) {
struct idr_layer *new;
- preempt_enable();
+ idr_preload_unlock();
new = kmem_cache_zalloc(idr_layer_cache, gfp_mask);
- preempt_disable();
+ idr_preload_lock();
if (!new)
break;
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 6dc09d8..0acf354 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -1858,6 +1858,7 @@ void locking_selftest(void)
printk(" --------------------------------------------------------------------------\n");
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* irq-context testcases:
*/
@@ -1870,6 +1871,28 @@ void locking_selftest(void)
DO_TESTCASE_6x2("irq read-recursion", irq_read_recursion);
// DO_TESTCASE_6x2B("irq read-recursion #2", irq_read_recursion2);
+#else
+ /* On -rt, we only do hardirq context test for raw spinlock */
+ DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 12);
+ DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 21);
+
+ DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 12);
+ DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 21);
+
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 123);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 132);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 213);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 231);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 312);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 321);
+
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 123);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 132);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 213);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 231);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 312);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 321);
+#endif
ww_tests();
diff --git a/lib/percpu-rwsem.c b/lib/percpu-rwsem.c
index 652a8ee..2db0f42 100644
--- a/lib/percpu-rwsem.c
+++ b/lib/percpu-rwsem.c
@@ -84,8 +84,12 @@ void percpu_down_read(struct percpu_rw_semaphore *brw)
down_read(&brw->rw_sem);
atomic_inc(&brw->slow_read_ctr);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ up_read(&brw->rw_sem);
+#else
/* avoid up_read()->rwsem_release() */
__up_read(&brw->rw_sem);
+#endif
}
void percpu_up_read(struct percpu_rw_semaphore *brw)
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 7811ed3..e7b61e8 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -221,12 +221,13 @@ radix_tree_node_alloc(struct radix_tree_root *root)
* succeed in getting a node here (and never reach
* kmem_cache_alloc)
*/
- rtp = &__get_cpu_var(radix_tree_preloads);
+ rtp = &get_cpu_var(radix_tree_preloads);
if (rtp->nr) {
ret = rtp->nodes[rtp->nr - 1];
rtp->nodes[rtp->nr - 1] = NULL;
rtp->nr--;
}
+ put_cpu_var(radix_tree_preloads);
}
if (ret == NULL)
ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
@@ -261,6 +262,7 @@ radix_tree_node_free(struct radix_tree_node *node)
call_rcu(&node->rcu_head, radix_tree_node_rcu_free);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Load up this CPU's radix_tree_node buffer with sufficient objects to
* ensure that the addition of a single element in the tree cannot fail. On
@@ -326,6 +328,7 @@ int radix_tree_maybe_preload(gfp_t gfp_mask)
return 0;
}
EXPORT_SYMBOL(radix_tree_maybe_preload);
+#endif
/*
* Return the maximum key which can be store into a
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index d16fa29..9c1236e 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -582,7 +582,7 @@ void sg_miter_stop(struct sg_mapping_iter *miter)
flush_kernel_dcache_page(miter->page);
if (miter->__flags & SG_MITER_ATOMIC) {
- WARN_ON_ONCE(preemptible());
+ WARN_ON_ONCE(!pagefault_disabled());
kunmap_atomic(miter->addr);
} else
kunmap(miter->page);
@@ -627,7 +627,7 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents,
if (!sg_miter_skip(&miter, skip))
return false;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
while (sg_miter_next(&miter) && offset < buflen) {
unsigned int len;
@@ -644,7 +644,7 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents,
sg_miter_stop(&miter);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return offset;
}
diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index 4c0d0e5..dbb1570 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -39,9 +39,9 @@ notrace unsigned int debug_smp_processor_id(void)
if (!printk_ratelimit())
goto out_enable;
- printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] "
- "code: %s/%d\n",
- preempt_count() - 1, current->comm, current->pid);
+ printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x %08x] "
+ "code: %s/%d\n", preempt_count() - 1,
+ __migrate_disabled(current), current->comm, current->pid);
print_symbol("caller is %s\n", (long)__builtin_return_address(0));
dump_stack();
diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c
index 0374a59..9497033 100644
--- a/lib/spinlock_debug.c
+++ b/lib/spinlock_debug.c
@@ -31,6 +31,7 @@ void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
EXPORT_SYMBOL(__raw_spin_lock_init);
+#ifndef CONFIG_PREEMPT_RT_FULL
void __rwlock_init(rwlock_t *lock, const char *name,
struct lock_class_key *key)
{
@@ -48,6 +49,7 @@ void __rwlock_init(rwlock_t *lock, const char *name,
}
EXPORT_SYMBOL(__rwlock_init);
+#endif
static void spin_dump(raw_spinlock_t *lock, const char *msg)
{
@@ -159,6 +161,7 @@ void do_raw_spin_unlock(raw_spinlock_t *lock)
arch_spin_unlock(&lock->raw_lock);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
static void rwlock_bug(rwlock_t *lock, const char *msg)
{
if (!debug_locks_off())
@@ -300,3 +303,5 @@ void do_raw_write_unlock(rwlock_t *lock)
debug_write_unlock(lock);
arch_write_unlock(&lock->raw_lock);
}
+
+#endif
diff --git a/localversion-rt b/localversion-rt
new file mode 100644
index 0000000..c5b71f9
--- /dev/null
+++ b/localversion-rt
@@ -0,0 +1 @@
+-rt25
diff --git a/mm/Kconfig b/mm/Kconfig
index 394838f..083685a 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -384,7 +384,7 @@ config NOMMU_INITIAL_TRIM_EXCESS
config TRANSPARENT_HUGEPAGE
bool "Transparent Hugepage Support"
- depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT_FULL
select COMPACTION
help
Transparent Hugepages allows the kernel to use huge pages and
diff --git a/mm/bounce.c b/mm/bounce.c
index 5a7d58f..b09bb4e 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -51,11 +51,11 @@ static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom)
unsigned long flags;
unsigned char *vto;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
vto = kmap_atomic(to->bv_page);
memcpy(vto + to->bv_offset, vfrom, to->bv_len);
kunmap_atomic(vto);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
#else /* CONFIG_HIGHMEM */
diff --git a/mm/filemap.c b/mm/filemap.c
index ae4846f..3d2d39a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1976,7 +1976,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
char *kaddr;
size_t copied;
- BUG_ON(!in_atomic());
+ BUG_ON(!pagefault_disabled());
kaddr = kmap_atomic(page);
if (likely(i->nr_segs == 1)) {
int left;
diff --git a/mm/highmem.c b/mm/highmem.c
index b32b70c..b1c7d43 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -29,10 +29,11 @@
#include <linux/kgdb.h>
#include <asm/tlbflush.h>
-
+#ifndef CONFIG_PREEMPT_RT_FULL
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
DEFINE_PER_CPU(int, __kmap_atomic_idx);
#endif
+#endif
/*
* Virtual_count is not a pure "count".
@@ -47,8 +48,9 @@ DEFINE_PER_CPU(int, __kmap_atomic_idx);
unsigned long totalhigh_pages __read_mostly;
EXPORT_SYMBOL(totalhigh_pages);
-
+#ifndef CONFIG_PREEMPT_RT_FULL
EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
+#endif
unsigned int nr_free_highpages (void)
{
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 15429b9..bc16ebc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2473,7 +2473,7 @@ static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync)
/* Notify other cpus that system-wide "drain" is running */
get_online_cpus();
- curcpu = get_cpu();
+ curcpu = get_cpu_light();
for_each_online_cpu(cpu) {
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
struct mem_cgroup *memcg;
@@ -2490,7 +2490,7 @@ static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync)
schedule_work_on(cpu, &stock->work);
}
}
- put_cpu();
+ put_cpu_light();
if (!sync)
goto out;
diff --git a/mm/memory.c b/mm/memory.c
index 22e67a2..0dcdc84 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3742,6 +3742,32 @@ unlock:
return 0;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+void pagefault_disable(void)
+{
+ migrate_disable();
+ current->pagefault_disabled++;
+ /*
+ * make sure to have issued the store before a pagefault
+ * can hit.
+ */
+ barrier();
+}
+EXPORT_SYMBOL(pagefault_disable);
+
+void pagefault_enable(void)
+{
+ /*
+ * make sure to issue those last loads/stores before enabling
+ * the pagefault handler again.
+ */
+ barrier();
+ current->pagefault_disabled--;
+ migrate_enable();
+}
+EXPORT_SYMBOL(pagefault_enable);
+#endif
+
/*
* By the time we get here, we already hold the mm semaphore
*/
@@ -4318,3 +4344,35 @@ void copy_user_huge_page(struct page *dst, struct page *src,
}
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
+
+#if defined(CONFIG_PREEMPT_RT_FULL) && (USE_SPLIT_PTLOCKS > 0)
+/*
+ * Heinous hack, relies on the caller doing something like:
+ *
+ * pte = alloc_pages(PGALLOC_GFP, 0);
+ * if (pte)
+ * pgtable_page_ctor(pte);
+ * return pte;
+ *
+ * This ensures we release the page and return NULL when the
+ * lock allocation fails.
+ */
+struct page *pte_lock_init(struct page *page)
+{
+ page->ptl = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
+ if (page->ptl) {
+ spin_lock_init(__pte_lockptr(page));
+ } else {
+ __free_page(page);
+ page = NULL;
+ }
+ return page;
+}
+
+void pte_lock_deinit(struct page *page)
+{
+ kfree(page->ptl);
+ page->mapping = NULL;
+}
+
+#endif
diff --git a/mm/mmu_context.c b/mm/mmu_context.c
index 8a8cd02..adfce87 100644
--- a/mm/mmu_context.c
+++ b/mm/mmu_context.c
@@ -23,6 +23,7 @@ void use_mm(struct mm_struct *mm)
struct task_struct *tsk = current;
task_lock(tsk);
+ preempt_disable_rt();
active_mm = tsk->active_mm;
if (active_mm != mm) {
atomic_inc(&mm->mm_count);
@@ -30,6 +31,7 @@ void use_mm(struct mm_struct *mm)
}
tsk->mm = mm;
switch_mm(active_mm, mm, tsk);
+ preempt_enable_rt();
task_unlock(tsk);
if (active_mm != mm)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6fca390..36c40eb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -61,6 +61,7 @@
#include <linux/page-debug-flags.h>
#include <linux/hugetlb.h>
#include <linux/sched/rt.h>
+#include <linux/locallock.h>
#include <asm/sections.h>
#include <asm/tlbflush.h>
@@ -230,6 +231,18 @@ EXPORT_SYMBOL(nr_node_ids);
EXPORT_SYMBOL(nr_online_nodes);
#endif
+static DEFINE_LOCAL_IRQ_LOCK(pa_lock);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define cpu_lock_irqsave(cpu, flags) \
+ local_lock_irqsave_on(pa_lock, flags, cpu)
+# define cpu_unlock_irqrestore(cpu, flags) \
+ local_unlock_irqrestore_on(pa_lock, flags, cpu)
+#else
+# define cpu_lock_irqsave(cpu, flags) local_irq_save(flags)
+# define cpu_unlock_irqrestore(cpu, flags) local_irq_restore(flags)
+#endif
+
int page_group_by_mobility_disabled __read_mostly;
void set_pageblock_migratetype(struct page *page, int migratetype)
@@ -635,7 +648,7 @@ static inline int free_pages_check(struct page *page)
}
/*
- * Frees a number of pages from the PCP lists
+ * Frees a number of pages which have been collected from the pcp lists.
* Assumes all pages on list are in same zone, and of same order.
* count is the number of pages to free.
*
@@ -646,15 +659,49 @@ static inline int free_pages_check(struct page *page)
* pinned" detection logic.
*/
static void free_pcppages_bulk(struct zone *zone, int count,
- struct per_cpu_pages *pcp)
+ struct list_head *list)
{
- int migratetype = 0;
- int batch_free = 0;
int to_free = count;
+ unsigned long flags;
- spin_lock(&zone->lock);
+ spin_lock_irqsave(&zone->lock, flags);
zone->pages_scanned = 0;
+ while (!list_empty(list)) {
+ struct page *page = list_first_entry(list, struct page, lru);
+ int mt; /* migratetype of the to-be-freed page */
+
+ /* must delete as __free_one_page list manipulates */
+ list_del(&page->lru);
+
+ mt = get_freepage_migratetype(page);
+ /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
+ __free_one_page(page, zone, 0, mt);
+ trace_mm_page_pcpu_drain(page, 0, mt);
+ if (likely(!is_migrate_isolate_page(page))) {
+ __mod_zone_page_state(zone, NR_FREE_PAGES, 1);
+ if (is_migrate_cma(mt))
+ __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
+ }
+
+ to_free--;
+ }
+ WARN_ON(to_free != 0);
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+/*
+ * Moves a number of pages from the PCP lists to free list which
+ * is freed outside of the locked region.
+ *
+ * Assumes all pages on list are in same zone, and of same order.
+ * count is the number of pages to free.
+ */
+static void isolate_pcp_pages(int to_free, struct per_cpu_pages *src,
+ struct list_head *dst)
+{
+ int migratetype = 0, batch_free = 0;
+
while (to_free) {
struct page *page;
struct list_head *list;
@@ -670,7 +717,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
batch_free++;
if (++migratetype == MIGRATE_PCPTYPES)
migratetype = 0;
- list = &pcp->lists[migratetype];
+ list = &src->lists[migratetype];
} while (list_empty(list));
/* This is the only non-empty list. Free them all. */
@@ -678,35 +725,25 @@ static void free_pcppages_bulk(struct zone *zone, int count,
batch_free = to_free;
do {
- int mt; /* migratetype of the to-be-freed page */
-
- page = list_entry(list->prev, struct page, lru);
- /* must delete as __free_one_page list manipulates */
+ page = list_last_entry(list, struct page, lru);
list_del(&page->lru);
- mt = get_freepage_migratetype(page);
- /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
- __free_one_page(page, zone, 0, mt);
- trace_mm_page_pcpu_drain(page, 0, mt);
- if (likely(!is_migrate_isolate_page(page))) {
- __mod_zone_page_state(zone, NR_FREE_PAGES, 1);
- if (is_migrate_cma(mt))
- __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
- }
+ list_add(&page->lru, dst);
} while (--to_free && --batch_free && !list_empty(list));
}
- spin_unlock(&zone->lock);
}
static void free_one_page(struct zone *zone, struct page *page, int order,
int migratetype)
{
- spin_lock(&zone->lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&zone->lock, flags);
zone->pages_scanned = 0;
__free_one_page(page, zone, order, migratetype);
if (unlikely(!is_migrate_isolate(migratetype)))
__mod_zone_freepage_state(zone, 1 << order, migratetype);
- spin_unlock(&zone->lock);
+ spin_unlock_irqrestore(&zone->lock, flags);
}
static bool free_pages_prepare(struct page *page, unsigned int order)
@@ -744,12 +781,12 @@ static void __free_pages_ok(struct page *page, unsigned int order)
if (!free_pages_prepare(page, order))
return;
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
__count_vm_events(PGFREE, 1 << order);
migratetype = get_pageblock_migratetype(page);
set_freepage_migratetype(page, migratetype);
free_one_page(page_zone(page), page, order, migratetype);
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
}
void __init __free_pages_bootmem(struct page *page, unsigned int order)
@@ -1204,20 +1241,22 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
{
unsigned long flags;
+ LIST_HEAD(dst);
int to_drain;
unsigned long batch;
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
batch = ACCESS_ONCE(pcp->batch);
if (pcp->count >= batch)
to_drain = batch;
else
to_drain = pcp->count;
if (to_drain > 0) {
- free_pcppages_bulk(zone, to_drain, pcp);
+ isolate_pcp_pages(to_drain, pcp, &dst);
pcp->count -= to_drain;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
+ free_pcppages_bulk(zone, to_drain, &dst);
}
static bool gfp_thisnode_allocation(gfp_t gfp_mask)
{
@@ -1245,16 +1284,21 @@ static void drain_pages(unsigned int cpu)
for_each_populated_zone(zone) {
struct per_cpu_pageset *pset;
struct per_cpu_pages *pcp;
+ LIST_HEAD(dst);
+ int count;
- local_irq_save(flags);
+ cpu_lock_irqsave(cpu, flags);
pset = per_cpu_ptr(zone->pageset, cpu);
pcp = &pset->pcp;
- if (pcp->count) {
- free_pcppages_bulk(zone, pcp->count, pcp);
+ count = pcp->count;
+ if (count) {
+ isolate_pcp_pages(count, pcp, &dst);
pcp->count = 0;
}
- local_irq_restore(flags);
+ cpu_unlock_irqrestore(cpu, flags);
+ if (count)
+ free_pcppages_bulk(zone, count, &dst);
}
}
@@ -1307,7 +1351,12 @@ void drain_all_pages(void)
else
cpumask_clear_cpu(cpu, &cpus_with_pcps);
}
+#ifndef CONFIG_PREEMPT_RT_BASE
on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1);
+#else
+ for_each_cpu(cpu, &cpus_with_pcps)
+ drain_pages(cpu);
+#endif
}
#ifdef CONFIG_HIBERNATION
@@ -1362,7 +1411,7 @@ void free_hot_cold_page(struct page *page, int cold)
migratetype = get_pageblock_migratetype(page);
set_freepage_migratetype(page, migratetype);
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
__count_vm_event(PGFREE);
/*
@@ -1388,12 +1437,17 @@ void free_hot_cold_page(struct page *page, int cold)
pcp->count++;
if (pcp->count >= pcp->high) {
unsigned long batch = ACCESS_ONCE(pcp->batch);
- free_pcppages_bulk(zone, batch, pcp);
+ LIST_HEAD(dst);
+
+ isolate_pcp_pages(batch, pcp, &dst);
pcp->count -= batch;
+ local_unlock_irqrestore(pa_lock, flags);
+ free_pcppages_bulk(zone, batch, &dst);
+ return;
}
out:
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
}
/*
@@ -1523,7 +1577,7 @@ again:
struct per_cpu_pages *pcp;
struct list_head *list;
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
pcp = &this_cpu_ptr(zone->pageset)->pcp;
list = &pcp->lists[migratetype];
if (list_empty(list)) {
@@ -1555,13 +1609,15 @@ again:
*/
WARN_ON_ONCE(order > 1);
}
- spin_lock_irqsave(&zone->lock, flags);
+ local_spin_lock_irqsave(pa_lock, &zone->lock, flags);
page = __rmqueue(zone, order, migratetype);
- spin_unlock(&zone->lock);
- if (!page)
+ if (!page) {
+ spin_unlock(&zone->lock);
goto failed;
+ }
__mod_zone_freepage_state(zone, -(1 << order),
get_pageblock_migratetype(page));
+ spin_unlock(&zone->lock);
}
/*
@@ -1573,7 +1629,7 @@ again:
__count_zone_vm_events(PGALLOC, zone, 1 << order);
zone_statistics(preferred_zone, zone, gfp_flags);
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
VM_BUG_ON(bad_range(zone, page));
if (prep_new_page(page, order, gfp_flags))
@@ -1581,7 +1637,7 @@ again:
return page;
failed:
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
return NULL;
}
@@ -2260,8 +2316,8 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
struct page *page;
/* Page migration frees to the PCP lists but we want merging */
- drain_pages(get_cpu());
- put_cpu();
+ drain_pages(get_cpu_light());
+ put_cpu_light();
page = get_page_from_freelist(gfp_mask, nodemask,
order, zonelist, high_zoneidx,
@@ -5463,6 +5519,7 @@ static int page_alloc_cpu_notify(struct notifier_block *self,
void __init page_alloc_init(void)
{
hotcpu_notifier(page_alloc_cpu_notify, 0);
+ local_irq_lock_init(pa_lock);
}
/*
@@ -6326,7 +6383,7 @@ void zone_pcp_reset(struct zone *zone)
struct per_cpu_pageset *pset;
/* avoid races with drain_pages() */
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
if (zone->pageset != &boot_pageset) {
for_each_online_cpu(cpu) {
pset = per_cpu_ptr(zone->pageset, cpu);
@@ -6335,7 +6392,7 @@ void zone_pcp_reset(struct zone *zone)
free_percpu(zone->pageset);
zone->pageset = &boot_pageset;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 6d757e3a..98caeee 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -13,6 +13,14 @@
static unsigned long total_usage;
+static void page_cgroup_lock_init(struct page_cgroup *pc, int nr_pages)
+{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ for (; nr_pages; nr_pages--, pc++)
+ spin_lock_init(&pc->pcg_lock);
+#endif
+}
+
#if !defined(CONFIG_SPARSEMEM)
@@ -60,6 +68,7 @@ static int __init alloc_node_page_cgroup(int nid)
return -ENOMEM;
NODE_DATA(nid)->node_page_cgroup = base;
total_usage += table_size;
+ page_cgroup_lock_init(base, nr_pages);
return 0;
}
@@ -150,6 +159,8 @@ static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
return -ENOMEM;
}
+ page_cgroup_lock_init(base, PAGES_PER_SECTION);
+
/*
* The passed "pfn" may not be aligned to SECTION. For the calculation
* we need to apply a mask.
diff --git a/mm/slab.h b/mm/slab.h
index a535033..8ffb287 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -247,7 +247,11 @@ static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
* The slab lists for all objects.
*/
struct kmem_cache_node {
+#ifdef CONFIG_SLUB
+ raw_spinlock_t list_lock;
+#else
spinlock_t list_lock;
+#endif
#ifdef CONFIG_SLAB
struct list_head slabs_partial; /* partial list first, better asm code */
diff --git a/mm/slub.c b/mm/slub.c
index 5c1343a..a164648 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1087,7 +1087,7 @@ static noinline struct kmem_cache_node *free_debug_processing(
{
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
- spin_lock_irqsave(&n->list_lock, *flags);
+ raw_spin_lock_irqsave(&n->list_lock, *flags);
slab_lock(page);
if (!check_slab(s, page))
@@ -1135,7 +1135,7 @@ out:
fail:
slab_unlock(page);
- spin_unlock_irqrestore(&n->list_lock, *flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, *flags);
slab_fix(s, "Object at 0x%p not freed", object);
return NULL;
}
@@ -1270,6 +1270,12 @@ static inline void slab_free_hook(struct kmem_cache *s, void *x) {}
#endif /* CONFIG_SLUB_DEBUG */
+struct slub_free_list {
+ raw_spinlock_t lock;
+ struct list_head list;
+};
+static DEFINE_PER_CPU(struct slub_free_list, slub_free_list);
+
/*
* Slab allocation and freeing
*/
@@ -1291,10 +1297,15 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
struct page *page;
struct kmem_cache_order_objects oo = s->oo;
gfp_t alloc_gfp;
+ bool enableirqs;
flags &= gfp_allowed_mask;
- if (flags & __GFP_WAIT)
+ enableirqs = (flags & __GFP_WAIT) != 0;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ enableirqs |= system_state == SYSTEM_RUNNING;
+#endif
+ if (enableirqs)
local_irq_enable();
flags |= s->allocflags;
@@ -1334,7 +1345,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
kmemcheck_mark_unallocated_pages(page, pages);
}
- if (flags & __GFP_WAIT)
+ if (enableirqs)
local_irq_disable();
if (!page)
return NULL;
@@ -1352,8 +1363,10 @@ static void setup_object(struct kmem_cache *s, struct page *page,
void *object)
{
setup_object_debug(s, page, object);
+#ifndef CONFIG_PREEMPT_RT_FULL
if (unlikely(s->ctor))
s->ctor(object);
+#endif
}
static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
@@ -1431,6 +1444,16 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
__free_memcg_kmem_pages(page, order);
}
+static void free_delayed(struct list_head *h)
+{
+ while(!list_empty(h)) {
+ struct page *page = list_first_entry(h, struct page, lru);
+
+ list_del(&page->lru);
+ __free_slab(page->slab_cache, page);
+ }
+}
+
#define need_reserve_slab_rcu \
(sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
@@ -1465,6 +1488,12 @@ static void free_slab(struct kmem_cache *s, struct page *page)
}
call_rcu(head, rcu_free_slab);
+ } else if (irqs_disabled()) {
+ struct slub_free_list *f = &__get_cpu_var(slub_free_list);
+
+ raw_spin_lock(&f->lock);
+ list_add(&page->lru, &f->list);
+ raw_spin_unlock(&f->lock);
} else
__free_slab(s, page);
}
@@ -1569,7 +1598,7 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
if (!n || !n->nr_partial)
return NULL;
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
list_for_each_entry_safe(page, page2, &n->partial, lru) {
void *t;
@@ -1594,7 +1623,7 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
break;
}
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
return object;
}
@@ -1837,7 +1866,7 @@ redo:
* that acquire_slab() will see a slab page that
* is frozen
*/
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
}
} else {
m = M_FULL;
@@ -1848,7 +1877,7 @@ redo:
* slabs from diagnostic functions will not see
* any frozen slabs.
*/
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
}
}
@@ -1883,7 +1912,7 @@ redo:
goto redo;
if (lock)
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
if (m == M_FREE) {
stat(s, DEACTIVATE_EMPTY);
@@ -1915,10 +1944,10 @@ static void unfreeze_partials(struct kmem_cache *s,
n2 = get_node(s, page_to_nid(page));
if (n != n2) {
if (n)
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
n = n2;
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
}
do {
@@ -1947,7 +1976,7 @@ static void unfreeze_partials(struct kmem_cache *s,
}
if (n)
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
while (discard_page) {
page = discard_page;
@@ -1985,14 +2014,21 @@ static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
pobjects = oldpage->pobjects;
pages = oldpage->pages;
if (drain && pobjects > s->cpu_partial) {
+ struct slub_free_list *f;
unsigned long flags;
+ LIST_HEAD(tofree);
/*
* partial array is full. Move the existing
* set to the per node partial list.
*/
local_irq_save(flags);
unfreeze_partials(s, this_cpu_ptr(s->cpu_slab));
+ f = &__get_cpu_var(slub_free_list);
+ raw_spin_lock(&f->lock);
+ list_splice_init(&f->list, &tofree);
+ raw_spin_unlock(&f->lock);
local_irq_restore(flags);
+ free_delayed(&tofree);
oldpage = NULL;
pobjects = 0;
pages = 0;
@@ -2056,7 +2092,22 @@ static bool has_cpu_slab(int cpu, void *info)
static void flush_all(struct kmem_cache *s)
{
+ LIST_HEAD(tofree);
+ int cpu;
+
on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC);
+ for_each_online_cpu(cpu) {
+ struct slub_free_list *f;
+
+ if (!has_cpu_slab(cpu, s))
+ continue;
+
+ f = &per_cpu(slub_free_list, cpu);
+ raw_spin_lock_irq(&f->lock);
+ list_splice_init(&f->list, &tofree);
+ raw_spin_unlock_irq(&f->lock);
+ free_delayed(&tofree);
+ }
}
/*
@@ -2084,10 +2135,10 @@ static unsigned long count_partial(struct kmem_cache_node *n,
unsigned long x = 0;
struct page *page;
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru)
x += get_count(page);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
return x;
}
@@ -2230,9 +2281,11 @@ static inline void *get_freelist(struct kmem_cache *s, struct page *page)
static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
unsigned long addr, struct kmem_cache_cpu *c)
{
+ struct slub_free_list *f;
void *freelist;
struct page *page;
unsigned long flags;
+ LIST_HEAD(tofree);
local_irq_save(flags);
#ifdef CONFIG_PREEMPT
@@ -2295,7 +2348,13 @@ load_freelist:
VM_BUG_ON(!c->page->frozen);
c->freelist = get_freepointer(s, freelist);
c->tid = next_tid(c->tid);
+out:
+ f = &__get_cpu_var(slub_free_list);
+ raw_spin_lock(&f->lock);
+ list_splice_init(&f->list, &tofree);
+ raw_spin_unlock(&f->lock);
local_irq_restore(flags);
+ free_delayed(&tofree);
return freelist;
new_slab:
@@ -2313,9 +2372,7 @@ new_slab:
if (unlikely(!freelist)) {
if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
slab_out_of_memory(s, gfpflags, node);
-
- local_irq_restore(flags);
- return NULL;
+ goto out;
}
page = c->page;
@@ -2330,8 +2387,7 @@ new_slab:
deactivate_slab(s, page, get_freepointer(s, freelist));
c->page = NULL;
c->freelist = NULL;
- local_irq_restore(flags);
- return freelist;
+ goto out;
}
/*
@@ -2416,6 +2472,10 @@ redo:
if (unlikely(gfpflags & __GFP_ZERO) && object)
memset(object, 0, s->object_size);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (unlikely(s->ctor) && object)
+ s->ctor(object);
+#endif
slab_post_alloc_hook(s, gfpflags, object);
@@ -2503,7 +2563,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
do {
if (unlikely(n)) {
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
n = NULL;
}
prior = page->freelist;
@@ -2535,7 +2595,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
* Otherwise the list_lock will synchronize with
* other processors updating the list of slabs.
*/
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
}
}
@@ -2577,7 +2637,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
add_partial(n, page, DEACTIVATE_TO_TAIL);
stat(s, FREE_ADD_PARTIAL);
}
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
return;
slab_empty:
@@ -2591,7 +2651,7 @@ slab_empty:
/* Slab must be on the full list */
remove_full(s, page);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
stat(s, FREE_SLAB);
discard_slab(s, page);
}
@@ -2793,7 +2853,7 @@ static void
init_kmem_cache_node(struct kmem_cache_node *n)
{
n->nr_partial = 0;
- spin_lock_init(&n->list_lock);
+ raw_spin_lock_init(&n->list_lock);
INIT_LIST_HEAD(&n->partial);
#ifdef CONFIG_SLUB_DEBUG
atomic_long_set(&n->nr_slabs, 0);
@@ -3379,7 +3439,7 @@ int kmem_cache_shrink(struct kmem_cache *s)
for (i = 0; i < objects; i++)
INIT_LIST_HEAD(slabs_by_inuse + i);
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
/*
* Build lists indexed by the items in use in each slab.
@@ -3400,7 +3460,7 @@ int kmem_cache_shrink(struct kmem_cache *s)
for (i = objects - 1; i > 0; i--)
list_splice(slabs_by_inuse + i, n->partial.prev);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
/* Release empty slabs */
list_for_each_entry_safe(page, t, slabs_by_inuse, lru)
@@ -3576,6 +3636,12 @@ void __init kmem_cache_init(void)
{
static __initdata struct kmem_cache boot_kmem_cache,
boot_kmem_cache_node;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ raw_spin_lock_init(&per_cpu(slub_free_list, cpu).lock);
+ INIT_LIST_HEAD(&per_cpu(slub_free_list, cpu).list);
+ }
if (debug_guardpage_minorder())
slub_max_order = 0;
@@ -3880,7 +3946,7 @@ static int validate_slab_node(struct kmem_cache *s,
struct page *page;
unsigned long flags;
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru) {
validate_slab_slab(s, page, map);
@@ -3903,7 +3969,7 @@ static int validate_slab_node(struct kmem_cache *s,
atomic_long_read(&n->nr_slabs));
out:
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
return count;
}
@@ -4093,12 +4159,12 @@ static int list_locations(struct kmem_cache *s, char *buf,
if (!atomic_long_read(&n->nr_slabs))
continue;
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru)
process_slab(&t, s, page, alloc, map);
list_for_each_entry(page, &n->full, lru)
process_slab(&t, s, page, alloc, map);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
}
for (i = 0; i < t.count; i++) {
diff --git a/mm/swap.c b/mm/swap.c
index aa4da5d..05a6951 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -32,6 +32,7 @@
#include <linux/gfp.h>
#include <linux/uio.h>
#include <linux/hugetlb.h>
+#include <linux/locallock.h>
#include "internal.h"
@@ -45,6 +46,9 @@ static DEFINE_PER_CPU(struct pagevec, lru_add_pvec);
static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs);
+static DEFINE_LOCAL_IRQ_LOCK(rotate_lock);
+static DEFINE_LOCAL_IRQ_LOCK(swapvec_lock);
+
/*
* This path almost never happens for VM activity - pages are normally
* freed via pagevecs. But it gets used by networking.
@@ -408,11 +412,11 @@ void rotate_reclaimable_page(struct page *page)
unsigned long flags;
page_cache_get(page);
- local_irq_save(flags);
+ local_lock_irqsave(rotate_lock, flags);
pvec = &__get_cpu_var(lru_rotate_pvecs);
if (!pagevec_add(pvec, page))
pagevec_move_tail(pvec);
- local_irq_restore(flags);
+ local_unlock_irqrestore(rotate_lock, flags);
}
}
@@ -463,12 +467,13 @@ static bool need_activate_page_drain(int cpu)
void activate_page(struct page *page)
{
if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
- struct pagevec *pvec = &get_cpu_var(activate_page_pvecs);
+ struct pagevec *pvec = &get_locked_var(swapvec_lock,
+ activate_page_pvecs);
page_cache_get(page);
if (!pagevec_add(pvec, page))
pagevec_lru_move_fn(pvec, __activate_page, NULL);
- put_cpu_var(activate_page_pvecs);
+ put_locked_var(swapvec_lock, activate_page_pvecs);
}
}
@@ -494,7 +499,7 @@ void activate_page(struct page *page)
static void __lru_cache_activate_page(struct page *page)
{
- struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
+ struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvec);
int i;
/*
@@ -516,7 +521,7 @@ static void __lru_cache_activate_page(struct page *page)
}
}
- put_cpu_var(lru_add_pvec);
+ put_locked_var(swapvec_lock, lru_add_pvec);
}
/*
@@ -556,13 +561,13 @@ EXPORT_SYMBOL(mark_page_accessed);
*/
void __lru_cache_add(struct page *page)
{
- struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
+ struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvec);
page_cache_get(page);
if (!pagevec_space(pvec))
__pagevec_lru_add(pvec);
pagevec_add(pvec, page);
- put_cpu_var(lru_add_pvec);
+ put_locked_var(swapvec_lock, lru_add_pvec);
}
EXPORT_SYMBOL(__lru_cache_add);
@@ -685,9 +690,9 @@ void lru_add_drain_cpu(int cpu)
unsigned long flags;
/* No harm done if a racing interrupt already did this */
- local_irq_save(flags);
+ local_lock_irqsave(rotate_lock, flags);
pagevec_move_tail(pvec);
- local_irq_restore(flags);
+ local_unlock_irqrestore(rotate_lock, flags);
}
pvec = &per_cpu(lru_deactivate_pvecs, cpu);
@@ -715,18 +720,19 @@ void deactivate_page(struct page *page)
return;
if (likely(get_page_unless_zero(page))) {
- struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs);
+ struct pagevec *pvec = &get_locked_var(swapvec_lock,
+ lru_deactivate_pvecs);
if (!pagevec_add(pvec, page))
pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);
- put_cpu_var(lru_deactivate_pvecs);
+ put_locked_var(swapvec_lock, lru_deactivate_pvecs);
}
}
void lru_add_drain(void)
{
- lru_add_drain_cpu(get_cpu());
- put_cpu();
+ lru_add_drain_cpu(local_lock_cpu(swapvec_lock));
+ local_unlock_cpu(swapvec_lock);
}
static void lru_add_drain_per_cpu(struct work_struct *dummy)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 1074543..d64289d 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -790,7 +790,7 @@ static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
struct vmap_block *vb;
struct vmap_area *va;
unsigned long vb_idx;
- int node, err;
+ int node, err, cpu;
node = numa_node_id();
@@ -828,11 +828,12 @@ static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
BUG_ON(err);
radix_tree_preload_end();
- vbq = &get_cpu_var(vmap_block_queue);
+ cpu = get_cpu_light();
+ vbq = &__get_cpu_var(vmap_block_queue);
spin_lock(&vbq->lock);
list_add_rcu(&vb->free_list, &vbq->free);
spin_unlock(&vbq->lock);
- put_cpu_var(vmap_block_queue);
+ put_cpu_light();
return vb;
}
@@ -900,6 +901,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
struct vmap_block *vb;
unsigned long addr = 0;
unsigned int order;
+ int cpu = 0;
BUG_ON(size & ~PAGE_MASK);
BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
@@ -915,7 +917,8 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
again:
rcu_read_lock();
- vbq = &get_cpu_var(vmap_block_queue);
+ cpu = get_cpu_light();
+ vbq = &__get_cpu_var(vmap_block_queue);
list_for_each_entry_rcu(vb, &vbq->free, free_list) {
int i;
@@ -939,7 +942,7 @@ next:
spin_unlock(&vb->lock);
}
- put_cpu_var(vmap_block_queue);
+ put_cpu_light();
rcu_read_unlock();
if (!addr) {
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 5a442a7..efea337 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -217,6 +217,7 @@ void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
long x;
long t;
+ preempt_disable_rt();
x = delta + __this_cpu_read(*p);
t = __this_cpu_read(pcp->stat_threshold);
@@ -226,6 +227,7 @@ void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
x = 0;
}
__this_cpu_write(*p, x);
+ preempt_enable_rt();
}
EXPORT_SYMBOL(__mod_zone_page_state);
@@ -258,6 +260,7 @@ void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
s8 __percpu *p = pcp->vm_stat_diff + item;
s8 v, t;
+ preempt_disable_rt();
v = __this_cpu_inc_return(*p);
t = __this_cpu_read(pcp->stat_threshold);
if (unlikely(v > t)) {
@@ -266,6 +269,7 @@ void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
zone_page_state_add(v + overstep, zone, item);
__this_cpu_write(*p, -overstep);
}
+ preempt_enable_rt();
}
void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
@@ -280,6 +284,7 @@ void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
s8 __percpu *p = pcp->vm_stat_diff + item;
s8 v, t;
+ preempt_disable_rt();
v = __this_cpu_dec_return(*p);
t = __this_cpu_read(pcp->stat_threshold);
if (unlikely(v < - t)) {
@@ -288,6 +293,7 @@ void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
zone_page_state_add(v - overstep, zone, item);
__this_cpu_write(*p, overstep);
}
+ preempt_enable_rt();
}
void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
diff --git a/net/core/dev.c b/net/core/dev.c
index 50f47e1..a1d035a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -175,6 +175,7 @@ static unsigned int napi_gen_id;
static DEFINE_HASHTABLE(napi_hash, 8);
static seqcount_t devnet_rename_seq;
+static DEFINE_MUTEX(devnet_rename_mutex);
static inline void dev_base_seq_inc(struct net *net)
{
@@ -196,14 +197,14 @@ static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
static inline void rps_lock(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
- spin_lock(&sd->input_pkt_queue.lock);
+ raw_spin_lock(&sd->input_pkt_queue.raw_lock);
#endif
}
static inline void rps_unlock(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
- spin_unlock(&sd->input_pkt_queue.lock);
+ raw_spin_unlock(&sd->input_pkt_queue.raw_lock);
#endif
}
@@ -826,7 +827,8 @@ retry:
strcpy(name, dev->name);
rcu_read_unlock();
if (read_seqcount_retry(&devnet_rename_seq, seq)) {
- cond_resched();
+ mutex_lock(&devnet_rename_mutex);
+ mutex_unlock(&devnet_rename_mutex);
goto retry;
}
@@ -1092,30 +1094,28 @@ int dev_change_name(struct net_device *dev, const char *newname)
if (dev->flags & IFF_UP)
return -EBUSY;
- write_seqcount_begin(&devnet_rename_seq);
+ mutex_lock(&devnet_rename_mutex);
+ __write_seqcount_begin(&devnet_rename_seq);
- if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
- write_seqcount_end(&devnet_rename_seq);
- return 0;
- }
+ if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
+ goto outunlock;
memcpy(oldname, dev->name, IFNAMSIZ);
err = dev_get_valid_name(net, dev, newname);
- if (err < 0) {
- write_seqcount_end(&devnet_rename_seq);
- return err;
- }
+ if (err < 0)
+ goto outunlock;
rollback:
ret = device_rename(&dev->dev, dev->name);
if (ret) {
memcpy(dev->name, oldname, IFNAMSIZ);
- write_seqcount_end(&devnet_rename_seq);
- return ret;
+ err = ret;
+ goto outunlock;
}
- write_seqcount_end(&devnet_rename_seq);
+ __write_seqcount_end(&devnet_rename_seq);
+ mutex_unlock(&devnet_rename_mutex);
write_lock_bh(&dev_base_lock);
hlist_del_rcu(&dev->name_hlist);
@@ -1134,7 +1134,8 @@ rollback:
/* err >= 0 after dev_alloc_name() or stores the first errno */
if (err >= 0) {
err = ret;
- write_seqcount_begin(&devnet_rename_seq);
+ mutex_lock(&devnet_rename_mutex);
+ __write_seqcount_begin(&devnet_rename_seq);
memcpy(dev->name, oldname, IFNAMSIZ);
goto rollback;
} else {
@@ -1144,6 +1145,11 @@ rollback:
}
return err;
+
+outunlock:
+ __write_seqcount_end(&devnet_rename_seq);
+ mutex_unlock(&devnet_rename_mutex);
+ return err;
}
/**
@@ -2132,6 +2138,7 @@ static inline void __netif_reschedule(struct Qdisc *q)
sd->output_queue_tailp = &q->next_sched;
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
void __netif_schedule(struct Qdisc *q)
@@ -2153,6 +2160,7 @@ void dev_kfree_skb_irq(struct sk_buff *skb)
sd->completion_queue = skb;
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
}
EXPORT_SYMBOL(dev_kfree_skb_irq);
@@ -3223,6 +3231,7 @@ enqueue:
rps_unlock(sd);
local_irq_restore(flags);
+ preempt_check_resched_rt();
atomic_long_inc(&skb->dev->rx_dropped);
kfree_skb(skb);
@@ -3260,7 +3269,7 @@ int netif_rx(struct sk_buff *skb)
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu;
- preempt_disable();
+ migrate_disable();
rcu_read_lock();
cpu = get_rps_cpu(skb->dev, skb, &rflow);
@@ -3270,13 +3279,13 @@ int netif_rx(struct sk_buff *skb)
ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
rcu_read_unlock();
- preempt_enable();
+ migrate_enable();
} else
#endif
{
unsigned int qtail;
- ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
- put_cpu();
+ ret = enqueue_to_backlog(skb, get_cpu_light(), &qtail);
+ put_cpu_light();
}
return ret;
}
@@ -3286,16 +3295,44 @@ int netif_rx_ni(struct sk_buff *skb)
{
int err;
- preempt_disable();
+ local_bh_disable();
err = netif_rx(skb);
- if (local_softirq_pending())
- do_softirq();
- preempt_enable();
+ local_bh_enable();
return err;
}
EXPORT_SYMBOL(netif_rx_ni);
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * RT runs ksoftirqd as a real time thread and the root_lock is a
+ * "sleeping spinlock". If the trylock fails then we can go into an
+ * infinite loop when ksoftirqd preempted the task which actually
+ * holds the lock, because we requeue q and raise NET_TX softirq
+ * causing ksoftirqd to loop forever.
+ *
+ * It's safe to use spin_lock on RT here as softirqs run in thread
+ * context and cannot deadlock against the thread which is holding
+ * root_lock.
+ *
+ * On !RT the trylock might fail, but there we bail out from the
+ * softirq loop after 10 attempts which we can't do on RT. And the
+ * task holding root_lock cannot be preempted, so the only downside of
+ * that trylock is that we need 10 loops to decide that we should have
+ * given up in the first one :)
+ */
+static inline int take_root_lock(spinlock_t *lock)
+{
+ spin_lock(lock);
+ return 1;
+}
+#else
+static inline int take_root_lock(spinlock_t *lock)
+{
+ return spin_trylock(lock);
+}
+#endif
+
static void net_tx_action(struct softirq_action *h)
{
struct softnet_data *sd = &__get_cpu_var(softnet_data);
@@ -3334,7 +3371,7 @@ static void net_tx_action(struct softirq_action *h)
head = head->next_sched;
root_lock = qdisc_lock(q);
- if (spin_trylock(root_lock)) {
+ if (take_root_lock(root_lock)) {
smp_mb__before_clear_bit();
clear_bit(__QDISC_STATE_SCHED,
&q->state);
@@ -3725,7 +3762,7 @@ static void flush_backlog(void *arg)
skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
if (skb->dev == dev) {
__skb_unlink(skb, &sd->input_pkt_queue);
- kfree_skb(skb);
+ __skb_queue_tail(&sd->tofree_queue, skb);
input_queue_head_incr(sd);
}
}
@@ -3734,10 +3771,13 @@ static void flush_backlog(void *arg)
skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
if (skb->dev == dev) {
__skb_unlink(skb, &sd->process_queue);
- kfree_skb(skb);
+ __skb_queue_tail(&sd->tofree_queue, skb);
input_queue_head_incr(sd);
}
}
+
+ if (!skb_queue_empty(&sd->tofree_queue))
+ raise_softirq_irqoff(NET_RX_SOFTIRQ);
}
static int napi_gro_complete(struct sk_buff *skb)
@@ -4094,6 +4134,7 @@ static void net_rps_action_and_irq_enable(struct softnet_data *sd)
} else
#endif
local_irq_enable();
+ preempt_check_resched_rt();
}
static int process_backlog(struct napi_struct *napi, int quota)
@@ -4166,6 +4207,7 @@ void __napi_schedule(struct napi_struct *n)
local_irq_save(flags);
____napi_schedule(&__get_cpu_var(softnet_data), n);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
EXPORT_SYMBOL(__napi_schedule);
@@ -4295,10 +4337,17 @@ static void net_rx_action(struct softirq_action *h)
struct softnet_data *sd = &__get_cpu_var(softnet_data);
unsigned long time_limit = jiffies + 2;
int budget = netdev_budget;
+ struct sk_buff *skb;
void *have;
local_irq_disable();
+ while ((skb = __skb_dequeue(&sd->tofree_queue))) {
+ local_irq_enable();
+ kfree_skb(skb);
+ local_irq_disable();
+ }
+
while (!list_empty(&sd->poll_list)) {
struct napi_struct *n;
int work, weight;
@@ -6417,6 +6466,7 @@ static int dev_cpu_callback(struct notifier_block *nfb,
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
/* Process offline CPU's input_pkt_queue */
while ((skb = __skb_dequeue(&oldsd->process_queue))) {
@@ -6427,6 +6477,9 @@ static int dev_cpu_callback(struct notifier_block *nfb,
netif_rx(skb);
input_queue_head_incr(oldsd);
}
+ while ((skb = __skb_dequeue(&oldsd->tofree_queue))) {
+ kfree_skb(skb);
+ }
return NOTIFY_OK;
}
@@ -6738,8 +6791,9 @@ static int __init net_dev_init(void)
struct softnet_data *sd = &per_cpu(softnet_data, i);
memset(sd, 0, sizeof(*sd));
- skb_queue_head_init(&sd->input_pkt_queue);
- skb_queue_head_init(&sd->process_queue);
+ skb_queue_head_init_raw(&sd->input_pkt_queue);
+ skb_queue_head_init_raw(&sd->process_queue);
+ skb_queue_head_init_raw(&sd->tofree_queue);
sd->completion_queue = NULL;
INIT_LIST_HEAD(&sd->poll_list);
sd->output_queue = NULL;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 15f9c56..41cd152 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -62,6 +62,7 @@
#include <linux/scatterlist.h>
#include <linux/errqueue.h>
#include <linux/prefetch.h>
+#include <linux/locallock.h>
#include <net/protocol.h>
#include <net/dst.h>
@@ -334,6 +335,7 @@ struct netdev_alloc_cache {
unsigned int pagecnt_bias;
};
static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache);
+static DEFINE_LOCAL_IRQ_LOCK(netdev_alloc_lock);
static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
{
@@ -342,7 +344,7 @@ static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
int order;
unsigned long flags;
- local_irq_save(flags);
+ local_lock_irqsave(netdev_alloc_lock, flags);
nc = &__get_cpu_var(netdev_alloc_cache);
if (unlikely(!nc->frag.page)) {
refill:
@@ -376,7 +378,7 @@ recycle:
nc->frag.offset += fragsz;
nc->pagecnt_bias--;
end:
- local_irq_restore(flags);
+ local_unlock_irqrestore(netdev_alloc_lock, flags);
return data;
}
diff --git a/net/core/sock.c b/net/core/sock.c
index 831a0d0..e57770c 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2339,12 +2339,11 @@ void lock_sock_nested(struct sock *sk, int subclass)
if (sk->sk_lock.owned)
__lock_sock(sk);
sk->sk_lock.owned = 1;
- spin_unlock(&sk->sk_lock.slock);
+ spin_unlock_bh(&sk->sk_lock.slock);
/*
* The sk_lock has mutex_lock() semantics here:
*/
mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
- local_bh_enable();
}
EXPORT_SYMBOL(lock_sock_nested);
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 5f7d11a..1f0c7e0 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -69,6 +69,7 @@
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/fcntl.h>
+#include <linux/sysrq.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
@@ -776,6 +777,30 @@ static void icmp_redirect(struct sk_buff *skb)
}
/*
+ * 32bit and 64bit have different timestamp length, so we check for
+ * the cookie at offset 20 and verify it is repeated at offset 50
+ */
+#define CO_POS0 20
+#define CO_POS1 50
+#define CO_SIZE sizeof(int)
+#define ICMP_SYSRQ_SIZE 57
+
+/*
+ * We got a ICMP_SYSRQ_SIZE sized ping request. Check for the cookie
+ * pattern and if it matches send the next byte as a trigger to sysrq.
+ */
+static void icmp_check_sysrq(struct net *net, struct sk_buff *skb)
+{
+ int cookie = htonl(net->ipv4.sysctl_icmp_echo_sysrq);
+ char *p = skb->data;
+
+ if (!memcmp(&cookie, p + CO_POS0, CO_SIZE) &&
+ !memcmp(&cookie, p + CO_POS1, CO_SIZE) &&
+ p[CO_POS0 + CO_SIZE] == p[CO_POS1 + CO_SIZE])
+ handle_sysrq(p[CO_POS0 + CO_SIZE]);
+}
+
+/*
* Handle ICMP_ECHO ("ping") requests.
*
* RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo
@@ -802,6 +827,11 @@ static void icmp_echo(struct sk_buff *skb)
icmp_param.data_len = skb->len;
icmp_param.head_len = sizeof(struct icmphdr);
icmp_reply(&icmp_param, skb);
+
+ if (skb->len == ICMP_SYSRQ_SIZE &&
+ net->ipv4.sysctl_icmp_echo_sysrq) {
+ icmp_check_sysrq(net, skb);
+ }
}
}
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 3982eab..8bb3b4a 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -79,6 +79,7 @@
#include <linux/mroute.h>
#include <linux/netlink.h>
#include <linux/tcp.h>
+#include <linux/locallock.h>
int sysctl_ip_default_ttl __read_mostly = IPDEFTTL;
EXPORT_SYMBOL(sysctl_ip_default_ttl);
@@ -1468,6 +1469,9 @@ static DEFINE_PER_CPU(struct inet_sock, unicast_sock) = {
.uc_ttl = -1,
};
+/* serialize concurrent calls on the same CPU to ip_send_unicast_reply */
+static DEFINE_LOCAL_IRQ_LOCK(unicast_lock);
+
void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr,
__be32 saddr, const struct ip_reply_arg *arg,
unsigned int len)
@@ -1505,7 +1509,7 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr,
if (IS_ERR(rt))
return;
- inet = &get_cpu_var(unicast_sock);
+ inet = &get_locked_var(unicast_lock, unicast_sock);
inet->tos = arg->tos;
sk = &inet->sk;
@@ -1529,7 +1533,7 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr,
ip_push_pending_frames(sk, &fl4);
}
- put_cpu_var(unicast_sock);
+ put_locked_var(unicast_lock, unicast_sock);
ip_rt_put(rt);
}
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 540279f..99461ed 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -812,6 +812,13 @@ static struct ctl_table ipv4_net_table[] = {
.proc_handler = proc_dointvec
},
{
+ .procname = "icmp_echo_sysrq",
+ .data = &init_net.ipv4.sysctl_icmp_echo_sysrq,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+ {
.procname = "icmp_ignore_bogus_error_responses",
.data = &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
.maxlen = sizeof(int),
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 1e5bd0d..62fba17 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3298,7 +3298,7 @@ void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
struct ieee80211_supported_band *sband;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
- WARN_ON_ONCE(softirq_count() == 0);
+ WARN_ON_ONCE_NONRT(softirq_count() == 0);
if (WARN_ON(status->band >= IEEE80211_NUM_BANDS))
goto drop;
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index 593b16e..6bd22aa 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -21,11 +21,17 @@
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <linux/slab.h>
+#include <linux/locallock.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include "nf_internals.h"
+#ifdef CONFIG_PREEMPT_RT_BASE
+DEFINE_LOCAL_IRQ_LOCK(xt_write_lock);
+EXPORT_PER_CPU_SYMBOL(xt_write_lock);
+#endif
+
static DEFINE_MUTEX(afinfo_mutex);
const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO] __read_mostly;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 88cfbc1..d1705d0 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -63,6 +63,7 @@
#include <linux/if_packet.h>
#include <linux/wireless.h>
#include <linux/kernel.h>
+#include <linux/delay.h>
#include <linux/kmod.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -630,7 +631,7 @@ static void prb_retire_rx_blk_timer_expired(unsigned long data)
if (BLOCK_NUM_PKTS(pbd)) {
while (atomic_read(&pkc->blk_fill_in_prog)) {
/* Waiting for skb_copy_bits to finish... */
- cpu_relax();
+ cpu_chill();
}
}
@@ -881,7 +882,7 @@ static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
if (!(status & TP_STATUS_BLK_TMO)) {
while (atomic_read(&pkc->blk_fill_in_prog)) {
/* Waiting for skb_copy_bits to finish... */
- cpu_relax();
+ cpu_chill();
}
}
prb_close_block(pkc, pbd, po, status);
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index e8fdb17..5a44c6e 100644
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -34,6 +34,7 @@
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/llist.h>
+#include <linux/delay.h>
#include "rds.h"
#include "ib.h"
@@ -286,7 +287,7 @@ static inline void wait_clean_list_grace(void)
for_each_online_cpu(cpu) {
flag = &per_cpu(clean_list_grace, cpu);
while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
- cpu_relax();
+ cpu_chill();
}
}
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index ed13d54..e87e6f9 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -865,7 +865,7 @@ void dev_deactivate_many(struct list_head *head)
/* Wait for outstanding qdisc_run calls. */
list_for_each_entry(dev, head, unreg_list)
while (some_qdisc_is_busy(dev))
- yield();
+ msleep(1);
}
void dev_deactivate(struct net_device *dev)
diff --git a/scripts/mkcompile_h b/scripts/mkcompile_h
index f221ddf..5f44009 100755
--- a/scripts/mkcompile_h
+++ b/scripts/mkcompile_h
@@ -4,7 +4,8 @@ TARGET=$1
ARCH=$2
SMP=$3
PREEMPT=$4
-CC=$5
+RT=$5
+CC=$6
vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
@@ -57,6 +58,7 @@ UTS_VERSION="#$VERSION"
CONFIG_FLAGS=""
if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
+if [ -n "$RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS RT"; fi
UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"
# Truncate to maximum length