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author | Ingo Molnar <mingo@kernel.org> | 2015-03-27 09:04:06 (GMT) |
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committer | Ingo Molnar <mingo@kernel.org> | 2015-03-27 09:04:06 (GMT) |
commit | 4bfe186dbe0a058680e4bfb0d673194f0ceaffd4 (patch) | |
tree | 5e374857dcd979d50f51c7091505784cb053d078 /arch | |
parent | 3c435c1e472ba344ee25f795f4807d4457e61f6c (diff) | |
parent | 42528795ac1c8d7ba021797ec004904168956d64 (diff) | |
download | linux-4bfe186dbe0a058680e4bfb0d673194f0ceaffd4.tar.xz |
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:
- Documentation updates.
- Changes permitting use of call_rcu() and friends very early in
boot, for example, before rcu_init() is invoked.
- Miscellaneous fixes.
- Add in-kernel API to enable and disable expediting of normal RCU
grace periods.
- Improve RCU's handling of (hotplug-) outgoing CPUs.
Note: ARM support is lagging a bit here, and these improved
diagnostics might generate (harmless) splats.
- NO_HZ_FULL_SYSIDLE fixes.
- Tiny RCU updates to make it more tiny.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/blackfin/mach-common/smp.c | 6 | ||||
-rw-r--r-- | arch/metag/kernel/smp.c | 5 | ||||
-rw-r--r-- | arch/x86/include/asm/cpu.h | 2 | ||||
-rw-r--r-- | arch/x86/include/asm/smp.h | 2 | ||||
-rw-r--r-- | arch/x86/kernel/smpboot.c | 39 | ||||
-rw-r--r-- | arch/x86/xen/smp.c | 46 |
6 files changed, 48 insertions, 52 deletions
diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c index 8ad3e90..1c72595 100644 --- a/arch/blackfin/mach-common/smp.c +++ b/arch/blackfin/mach-common/smp.c @@ -413,16 +413,14 @@ int __cpu_disable(void) return 0; } -static DECLARE_COMPLETION(cpu_killed); - int __cpu_die(unsigned int cpu) { - return wait_for_completion_timeout(&cpu_killed, 5000); + return cpu_wait_death(cpu, 5); } void cpu_die(void) { - complete(&cpu_killed); + (void)cpu_report_death(); atomic_dec(&init_mm.mm_users); atomic_dec(&init_mm.mm_count); diff --git a/arch/metag/kernel/smp.c b/arch/metag/kernel/smp.c index f006d22..ac3a199 100644 --- a/arch/metag/kernel/smp.c +++ b/arch/metag/kernel/smp.c @@ -261,7 +261,6 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) } #ifdef CONFIG_HOTPLUG_CPU -static DECLARE_COMPLETION(cpu_killed); /* * __cpu_disable runs on the processor to be shutdown. @@ -299,7 +298,7 @@ int __cpu_disable(void) */ void __cpu_die(unsigned int cpu) { - if (!wait_for_completion_timeout(&cpu_killed, msecs_to_jiffies(1))) + if (!cpu_wait_death(cpu, 1)) pr_err("CPU%u: unable to kill\n", cpu); } @@ -314,7 +313,7 @@ void cpu_die(void) local_irq_disable(); idle_task_exit(); - complete(&cpu_killed); + (void)cpu_report_death(); asm ("XOR TXENABLE, D0Re0,D0Re0\n"); } diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index d2b1298..bf2caa1 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -34,8 +34,6 @@ extern int _debug_hotplug_cpu(int cpu, int action); #endif #endif -DECLARE_PER_CPU(int, cpu_state); - int mwait_usable(const struct cpuinfo_x86 *); #endif /* _ASM_X86_CPU_H */ diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 8cd1cc3..a5cb4f6 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -150,12 +150,12 @@ static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask) } void cpu_disable_common(void); -void cpu_die_common(unsigned int cpu); void native_smp_prepare_boot_cpu(void); void native_smp_prepare_cpus(unsigned int max_cpus); void native_smp_cpus_done(unsigned int max_cpus); int native_cpu_up(unsigned int cpunum, struct task_struct *tidle); int native_cpu_disable(void); +int common_cpu_die(unsigned int cpu); void native_cpu_die(unsigned int cpu); void native_play_dead(void); void play_dead_common(void); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index febc6aa..c8fa349 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -77,9 +77,6 @@ #include <asm/realmode.h> #include <asm/misc.h> -/* State of each CPU */ -DEFINE_PER_CPU(int, cpu_state) = { 0 }; - /* Number of siblings per CPU package */ int smp_num_siblings = 1; EXPORT_SYMBOL(smp_num_siblings); @@ -257,7 +254,7 @@ static void notrace start_secondary(void *unused) lock_vector_lock(); set_cpu_online(smp_processor_id(), true); unlock_vector_lock(); - per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; + cpu_set_state_online(smp_processor_id()); x86_platform.nmi_init(); /* enable local interrupts */ @@ -948,7 +945,10 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle) */ mtrr_save_state(); - per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; + /* x86 CPUs take themselves offline, so delayed offline is OK. */ + err = cpu_check_up_prepare(cpu); + if (err && err != -EBUSY) + return err; /* the FPU context is blank, nobody can own it */ __cpu_disable_lazy_restore(cpu); @@ -1191,7 +1191,7 @@ void __init native_smp_prepare_boot_cpu(void) switch_to_new_gdt(me); /* already set me in cpu_online_mask in boot_cpu_init() */ cpumask_set_cpu(me, cpu_callout_mask); - per_cpu(cpu_state, me) = CPU_ONLINE; + cpu_set_state_online(me); } void __init native_smp_cpus_done(unsigned int max_cpus) @@ -1318,14 +1318,10 @@ static void __ref remove_cpu_from_maps(int cpu) numa_remove_cpu(cpu); } -static DEFINE_PER_CPU(struct completion, die_complete); - void cpu_disable_common(void) { int cpu = smp_processor_id(); - init_completion(&per_cpu(die_complete, smp_processor_id())); - remove_siblinginfo(cpu); /* It's now safe to remove this processor from the online map */ @@ -1349,24 +1345,27 @@ int native_cpu_disable(void) return 0; } -void cpu_die_common(unsigned int cpu) +int common_cpu_die(unsigned int cpu) { - wait_for_completion_timeout(&per_cpu(die_complete, cpu), HZ); -} + int ret = 0; -void native_cpu_die(unsigned int cpu) -{ /* We don't do anything here: idle task is faking death itself. */ - cpu_die_common(cpu); - /* They ack this in play_dead() by setting CPU_DEAD */ - if (per_cpu(cpu_state, cpu) == CPU_DEAD) { + if (cpu_wait_death(cpu, 5)) { if (system_state == SYSTEM_RUNNING) pr_info("CPU %u is now offline\n", cpu); } else { pr_err("CPU %u didn't die...\n", cpu); + ret = -1; } + + return ret; +} + +void native_cpu_die(unsigned int cpu) +{ + common_cpu_die(cpu); } void play_dead_common(void) @@ -1375,10 +1374,8 @@ void play_dead_common(void) reset_lazy_tlbstate(); amd_e400_remove_cpu(raw_smp_processor_id()); - mb(); /* Ack it */ - __this_cpu_write(cpu_state, CPU_DEAD); - complete(&per_cpu(die_complete, smp_processor_id())); + (void)cpu_report_death(); /* * With physical CPU hotplug, we should halt the cpu diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 08e8489..1c5e760 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -90,14 +90,10 @@ static void cpu_bringup(void) set_cpu_online(cpu, true); - this_cpu_write(cpu_state, CPU_ONLINE); - - wmb(); + cpu_set_state_online(cpu); /* Implies full memory barrier. */ /* We can take interrupts now: we're officially "up". */ local_irq_enable(); - - wmb(); /* make sure everything is out */ } /* @@ -459,7 +455,13 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle) xen_setup_timer(cpu); xen_init_lock_cpu(cpu); - per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; + /* + * PV VCPUs are always successfully taken down (see 'while' loop + * in xen_cpu_die()), so -EBUSY is an error. + */ + rc = cpu_check_up_prepare(cpu); + if (rc) + return rc; /* make sure interrupts start blocked */ per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1; @@ -479,10 +481,8 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle) rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL); BUG_ON(rc); - while(per_cpu(cpu_state, cpu) != CPU_ONLINE) { + while (cpu_report_state(cpu) != CPU_ONLINE) HYPERVISOR_sched_op(SCHEDOP_yield, NULL); - barrier(); - } return 0; } @@ -511,11 +511,11 @@ static void xen_cpu_die(unsigned int cpu) schedule_timeout(HZ/10); } - cpu_die_common(cpu); - - xen_smp_intr_free(cpu); - xen_uninit_lock_cpu(cpu); - xen_teardown_timer(cpu); + if (common_cpu_die(cpu) == 0) { + xen_smp_intr_free(cpu); + xen_uninit_lock_cpu(cpu); + xen_teardown_timer(cpu); + } } static void xen_play_dead(void) /* used only with HOTPLUG_CPU */ @@ -747,6 +747,16 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus) static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle) { int rc; + + /* + * This can happen if CPU was offlined earlier and + * offlining timed out in common_cpu_die(). + */ + if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) { + xen_smp_intr_free(cpu); + xen_uninit_lock_cpu(cpu); + } + /* * xen_smp_intr_init() needs to run before native_cpu_up() * so that IPI vectors are set up on the booting CPU before @@ -768,12 +778,6 @@ static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle) return rc; } -static void xen_hvm_cpu_die(unsigned int cpu) -{ - xen_cpu_die(cpu); - native_cpu_die(cpu); -} - void __init xen_hvm_smp_init(void) { if (!xen_have_vector_callback) @@ -781,7 +785,7 @@ void __init xen_hvm_smp_init(void) smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus; smp_ops.smp_send_reschedule = xen_smp_send_reschedule; smp_ops.cpu_up = xen_hvm_cpu_up; - smp_ops.cpu_die = xen_hvm_cpu_die; + smp_ops.cpu_die = xen_cpu_die; smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi; smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi; smp_ops.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu; |