summaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c28
-rw-r--r--kernel/cpuset.c13
-rw-r--r--kernel/hrtimer.c41
-rw-r--r--kernel/irq/chip.c2
-rw-r--r--kernel/irq/numa_migrate.c7
-rw-r--r--kernel/module.c35
-rw-r--r--kernel/sched.c10
-rw-r--r--kernel/sched_fair.c32
-rw-r--r--kernel/signal.c2
-rw-r--r--kernel/smp.c36
-rw-r--r--kernel/time/tick-common.c26
-rw-r--r--kernel/trace/ftrace.c27
-rw-r--r--kernel/trace/ring_buffer.c15
-rw-r--r--kernel/trace/trace.c5
-rw-r--r--kernel/trace/trace_irqsoff.c1
-rw-r--r--kernel/trace/trace_sched_wakeup.c1
16 files changed, 229 insertions, 52 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index c298310..5a54ff4 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1115,8 +1115,10 @@ static void cgroup_kill_sb(struct super_block *sb) {
}
write_unlock(&css_set_lock);
- list_del(&root->root_list);
- root_count--;
+ if (!list_empty(&root->root_list)) {
+ list_del(&root->root_list);
+ root_count--;
+ }
mutex_unlock(&cgroup_mutex);
@@ -2434,7 +2436,9 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
err_remove:
+ cgroup_lock_hierarchy(root);
list_del(&cgrp->sibling);
+ cgroup_unlock_hierarchy(root);
root->number_of_cgroups--;
err_destroy:
@@ -2507,7 +2511,7 @@ static int cgroup_clear_css_refs(struct cgroup *cgrp)
for_each_subsys(cgrp->root, ss) {
struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
int refcnt;
- do {
+ while (1) {
/* We can only remove a CSS with a refcnt==1 */
refcnt = atomic_read(&css->refcnt);
if (refcnt > 1) {
@@ -2521,7 +2525,10 @@ static int cgroup_clear_css_refs(struct cgroup *cgrp)
* css_tryget() to spin until we set the
* CSS_REMOVED bits or abort
*/
- } while (atomic_cmpxchg(&css->refcnt, refcnt, 0) != refcnt);
+ if (atomic_cmpxchg(&css->refcnt, refcnt, 0) == refcnt)
+ break;
+ cpu_relax();
+ }
}
done:
for_each_subsys(cgrp->root, ss) {
@@ -2991,20 +2998,21 @@ int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys,
mutex_unlock(&cgroup_mutex);
return 0;
}
- task_lock(tsk);
- cg = tsk->cgroups;
- parent = task_cgroup(tsk, subsys->subsys_id);
/* Pin the hierarchy */
- if (!atomic_inc_not_zero(&parent->root->sb->s_active)) {
+ if (!atomic_inc_not_zero(&root->sb->s_active)) {
/* We race with the final deactivate_super() */
mutex_unlock(&cgroup_mutex);
return 0;
}
/* Keep the cgroup alive */
+ task_lock(tsk);
+ parent = task_cgroup(tsk, subsys->subsys_id);
+ cg = tsk->cgroups;
get_css_set(cg);
task_unlock(tsk);
+
mutex_unlock(&cgroup_mutex);
/* Now do the VFS work to create a cgroup */
@@ -3043,7 +3051,7 @@ int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys,
mutex_unlock(&inode->i_mutex);
put_css_set(cg);
- deactivate_super(parent->root->sb);
+ deactivate_super(root->sb);
/* The cgroup is still accessible in the VFS, but
* we're not going to try to rmdir() it at this
* point. */
@@ -3069,7 +3077,7 @@ int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys,
mutex_lock(&cgroup_mutex);
put_css_set(cg);
mutex_unlock(&cgroup_mutex);
- deactivate_super(parent->root->sb);
+ deactivate_super(root->sb);
return ret;
}
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index a856788..f76db9d 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -61,6 +61,14 @@
#include <linux/cgroup.h>
/*
+ * Workqueue for cpuset related tasks.
+ *
+ * Using kevent workqueue may cause deadlock when memory_migrate
+ * is set. So we create a separate workqueue thread for cpuset.
+ */
+static struct workqueue_struct *cpuset_wq;
+
+/*
* Tracks how many cpusets are currently defined in system.
* When there is only one cpuset (the root cpuset) we can
* short circuit some hooks.
@@ -831,7 +839,7 @@ static DECLARE_WORK(rebuild_sched_domains_work, do_rebuild_sched_domains);
*/
static void async_rebuild_sched_domains(void)
{
- schedule_work(&rebuild_sched_domains_work);
+ queue_work(cpuset_wq, &rebuild_sched_domains_work);
}
/*
@@ -2111,6 +2119,9 @@ void __init cpuset_init_smp(void)
hotcpu_notifier(cpuset_track_online_cpus, 0);
hotplug_memory_notifier(cpuset_track_online_nodes, 10);
+
+ cpuset_wq = create_singlethread_workqueue("cpuset");
+ BUG_ON(!cpuset_wq);
}
/**
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index f33afb0..f394d2a 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -501,6 +501,13 @@ static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
continue;
timer = rb_entry(base->first, struct hrtimer, node);
expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
+ /*
+ * clock_was_set() has changed base->offset so the
+ * result might be negative. Fix it up to prevent a
+ * false positive in clockevents_program_event()
+ */
+ if (expires.tv64 < 0)
+ expires.tv64 = 0;
if (expires.tv64 < cpu_base->expires_next.tv64)
cpu_base->expires_next = expires;
}
@@ -1158,6 +1165,29 @@ static void __run_hrtimer(struct hrtimer *timer)
#ifdef CONFIG_HIGH_RES_TIMERS
+static int force_clock_reprogram;
+
+/*
+ * After 5 iteration's attempts, we consider that hrtimer_interrupt()
+ * is hanging, which could happen with something that slows the interrupt
+ * such as the tracing. Then we force the clock reprogramming for each future
+ * hrtimer interrupts to avoid infinite loops and use the min_delta_ns
+ * threshold that we will overwrite.
+ * The next tick event will be scheduled to 3 times we currently spend on
+ * hrtimer_interrupt(). This gives a good compromise, the cpus will spend
+ * 1/4 of their time to process the hrtimer interrupts. This is enough to
+ * let it running without serious starvation.
+ */
+
+static inline void
+hrtimer_interrupt_hanging(struct clock_event_device *dev,
+ ktime_t try_time)
+{
+ force_clock_reprogram = 1;
+ dev->min_delta_ns = (unsigned long)try_time.tv64 * 3;
+ printk(KERN_WARNING "hrtimer: interrupt too slow, "
+ "forcing clock min delta to %lu ns\n", dev->min_delta_ns);
+}
/*
* High resolution timer interrupt
* Called with interrupts disabled
@@ -1167,6 +1197,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
struct hrtimer_clock_base *base;
ktime_t expires_next, now;
+ int nr_retries = 0;
int i;
BUG_ON(!cpu_base->hres_active);
@@ -1174,6 +1205,10 @@ void hrtimer_interrupt(struct clock_event_device *dev)
dev->next_event.tv64 = KTIME_MAX;
retry:
+ /* 5 retries is enough to notice a hang */
+ if (!(++nr_retries % 5))
+ hrtimer_interrupt_hanging(dev, ktime_sub(ktime_get(), now));
+
now = ktime_get();
expires_next.tv64 = KTIME_MAX;
@@ -1226,7 +1261,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
/* Reprogramming necessary ? */
if (expires_next.tv64 != KTIME_MAX) {
- if (tick_program_event(expires_next, 0))
+ if (tick_program_event(expires_next, force_clock_reprogram))
goto retry;
}
}
@@ -1580,6 +1615,10 @@ static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self,
break;
#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_DYING:
+ case CPU_DYING_FROZEN:
+ clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DYING, &scpu);
+ break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
{
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index c248eba..122fef4 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -386,6 +386,7 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
out_unlock:
spin_unlock(&desc->lock);
}
+EXPORT_SYMBOL_GPL(handle_level_irq);
/**
* handle_fasteoi_irq - irq handler for transparent controllers
@@ -596,6 +597,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
}
spin_unlock_irqrestore(&desc->lock, flags);
}
+EXPORT_SYMBOL_GPL(__set_irq_handler);
void
set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
index 666260e..7f9b804 100644
--- a/kernel/irq/numa_migrate.c
+++ b/kernel/irq/numa_migrate.c
@@ -78,7 +78,7 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
desc = irq_desc_ptrs[irq];
if (desc && old_desc != desc)
- goto out_unlock;
+ goto out_unlock;
node = cpu_to_node(cpu);
desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
@@ -97,10 +97,15 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
}
irq_desc_ptrs[irq] = desc;
+ spin_unlock_irqrestore(&sparse_irq_lock, flags);
/* free the old one */
free_one_irq_desc(old_desc, desc);
+ spin_unlock(&old_desc->lock);
kfree(old_desc);
+ spin_lock(&desc->lock);
+
+ return desc;
out_unlock:
spin_unlock_irqrestore(&sparse_irq_lock, flags);
diff --git a/kernel/module.c b/kernel/module.c
index e8b51d4..ba22484 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -573,13 +573,13 @@ static char last_unloaded_module[MODULE_NAME_LEN+1];
/* Init the unload section of the module. */
static void module_unload_init(struct module *mod)
{
- unsigned int i;
+ int cpu;
INIT_LIST_HEAD(&mod->modules_which_use_me);
- for (i = 0; i < NR_CPUS; i++)
- local_set(&mod->ref[i].count, 0);
+ for_each_possible_cpu(cpu)
+ local_set(__module_ref_addr(mod, cpu), 0);
/* Hold reference count during initialization. */
- local_set(&mod->ref[raw_smp_processor_id()].count, 1);
+ local_set(__module_ref_addr(mod, raw_smp_processor_id()), 1);
/* Backwards compatibility macros put refcount during init. */
mod->waiter = current;
}
@@ -717,10 +717,11 @@ static int try_stop_module(struct module *mod, int flags, int *forced)
unsigned int module_refcount(struct module *mod)
{
- unsigned int i, total = 0;
+ unsigned int total = 0;
+ int cpu;
- for (i = 0; i < NR_CPUS; i++)
- total += local_read(&mod->ref[i].count);
+ for_each_possible_cpu(cpu)
+ total += local_read(__module_ref_addr(mod, cpu));
return total;
}
EXPORT_SYMBOL(module_refcount);
@@ -894,7 +895,7 @@ void module_put(struct module *module)
{
if (module) {
unsigned int cpu = get_cpu();
- local_dec(&module->ref[cpu].count);
+ local_dec(__module_ref_addr(module, cpu));
/* Maybe they're waiting for us to drop reference? */
if (unlikely(!module_is_live(module)))
wake_up_process(module->waiter);
@@ -1464,7 +1465,10 @@ static void free_module(struct module *mod)
kfree(mod->args);
if (mod->percpu)
percpu_modfree(mod->percpu);
-
+#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+ if (mod->refptr)
+ percpu_modfree(mod->refptr);
+#endif
/* Free lock-classes: */
lockdep_free_key_range(mod->module_core, mod->core_size);
@@ -2011,6 +2015,14 @@ static noinline struct module *load_module(void __user *umod,
if (err < 0)
goto free_mod;
+#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+ mod->refptr = percpu_modalloc(sizeof(local_t), __alignof__(local_t),
+ mod->name);
+ if (!mod->refptr) {
+ err = -ENOMEM;
+ goto free_mod;
+ }
+#endif
if (pcpuindex) {
/* We have a special allocation for this section. */
percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
@@ -2018,7 +2030,7 @@ static noinline struct module *load_module(void __user *umod,
mod->name);
if (!percpu) {
err = -ENOMEM;
- goto free_mod;
+ goto free_percpu;
}
sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
mod->percpu = percpu;
@@ -2282,6 +2294,9 @@ static noinline struct module *load_module(void __user *umod,
free_percpu:
if (percpu)
percpu_modfree(percpu);
+#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+ percpu_modfree(mod->refptr);
+#endif
free_mod:
kfree(args);
free_hdr:
diff --git a/kernel/sched.c b/kernel/sched.c
index c71d7d5..4007561 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2266,6 +2266,16 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
if (!sched_feat(SYNC_WAKEUPS))
sync = 0;
+ if (!sync) {
+ if (current->se.avg_overlap < sysctl_sched_migration_cost &&
+ p->se.avg_overlap < sysctl_sched_migration_cost)
+ sync = 1;
+ } else {
+ if (current->se.avg_overlap >= sysctl_sched_migration_cost ||
+ p->se.avg_overlap >= sysctl_sched_migration_cost)
+ sync = 0;
+ }
+
#ifdef CONFIG_SMP
if (sched_feat(LB_WAKEUP_UPDATE)) {
struct sched_domain *sd;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5cc1c16..a7e50ba 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -719,7 +719,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
__enqueue_entity(cfs_rq, se);
}
-static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
+static void __clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
if (cfs_rq->last == se)
cfs_rq->last = NULL;
@@ -728,6 +728,12 @@ static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
cfs_rq->next = NULL;
}
+static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ for_each_sched_entity(se)
+ __clear_buddies(cfs_rq_of(se), se);
+}
+
static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
{
@@ -768,8 +774,14 @@ 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)
+ if (delta_exec > ideal_runtime) {
resched_task(rq_of(cfs_rq)->curr);
+ /*
+ * The current task ran long enough, ensure it doesn't get
+ * re-elected due to buddy favours.
+ */
+ clear_buddies(cfs_rq, curr);
+ }
}
static void
@@ -1179,20 +1191,15 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
int idx, unsigned long load, unsigned long this_load,
unsigned int imbalance)
{
- struct task_struct *curr = this_rq->curr;
- struct task_group *tg;
unsigned long tl = this_load;
unsigned long tl_per_task;
+ struct task_group *tg;
unsigned long weight;
int balanced;
if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
return 0;
- if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost ||
- p->se.avg_overlap > sysctl_sched_migration_cost))
- sync = 0;
-
/*
* If sync wakeup then subtract the (maximum possible)
* effect of the currently running task from the load
@@ -1419,9 +1426,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
if (!sched_feat(WAKEUP_PREEMPT))
return;
- if (sched_feat(WAKEUP_OVERLAP) && (sync ||
- (se->avg_overlap < sysctl_sched_migration_cost &&
- pse->avg_overlap < sysctl_sched_migration_cost))) {
+ if (sched_feat(WAKEUP_OVERLAP) && sync) {
resched_task(curr);
return;
}
@@ -1452,6 +1457,11 @@ static struct task_struct *pick_next_task_fair(struct rq *rq)
do {
se = pick_next_entity(cfs_rq);
+ /*
+ * If se was a buddy, clear it so that it will have to earn
+ * the favour again.
+ */
+ __clear_buddies(cfs_rq, se);
set_next_entity(cfs_rq, se);
cfs_rq = group_cfs_rq(se);
} while (cfs_rq);
diff --git a/kernel/signal.c b/kernel/signal.c
index e737597..b6b3676 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -909,7 +909,9 @@ static void print_fatal_signal(struct pt_regs *regs, int signr)
}
#endif
printk("\n");
+ preempt_disable();
show_regs(regs);
+ preempt_enable();
}
static int __init setup_print_fatal_signals(char *str)
diff --git a/kernel/smp.c b/kernel/smp.c
index 5cfa0e5..bbedbb7 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -18,6 +18,7 @@ __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_function_lock);
enum {
CSD_FLAG_WAIT = 0x01,
CSD_FLAG_ALLOC = 0x02,
+ CSD_FLAG_LOCK = 0x04,
};
struct call_function_data {
@@ -186,6 +187,9 @@ void generic_smp_call_function_single_interrupt(void)
if (data_flags & CSD_FLAG_WAIT) {
smp_wmb();
data->flags &= ~CSD_FLAG_WAIT;
+ } else if (data_flags & CSD_FLAG_LOCK) {
+ smp_wmb();
+ data->flags &= ~CSD_FLAG_LOCK;
} else if (data_flags & CSD_FLAG_ALLOC)
kfree(data);
}
@@ -196,6 +200,8 @@ void generic_smp_call_function_single_interrupt(void)
}
}
+static DEFINE_PER_CPU(struct call_single_data, csd_data);
+
/*
* smp_call_function_single - Run a function on a specific CPU
* @func: The function to run. This must be fast and non-blocking.
@@ -224,14 +230,38 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
func(info);
local_irq_restore(flags);
} else if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) {
- struct call_single_data *data = NULL;
+ struct call_single_data *data;
if (!wait) {
+ /*
+ * We are calling a function on a single CPU
+ * and we are not going to wait for it to finish.
+ * We first try to allocate the data, but if we
+ * fail, we fall back to use a per cpu data to pass
+ * the information to that CPU. Since all callers
+ * of this code will use the same data, we must
+ * synchronize the callers to prevent a new caller
+ * from corrupting the data before the callee
+ * can access it.
+ *
+ * The CSD_FLAG_LOCK is used to let us know when
+ * the IPI handler is done with the data.
+ * The first caller will set it, and the callee
+ * will clear it. The next caller must wait for
+ * it to clear before we set it again. This
+ * will make sure the callee is done with the
+ * data before a new caller will use it.
+ */
data = kmalloc(sizeof(*data), GFP_ATOMIC);
if (data)
data->flags = CSD_FLAG_ALLOC;
- }
- if (!data) {
+ else {
+ data = &per_cpu(csd_data, me);
+ while (data->flags & CSD_FLAG_LOCK)
+ cpu_relax();
+ data->flags = CSD_FLAG_LOCK;
+ }
+ } else {
data = &d;
data->flags = CSD_FLAG_WAIT;
}
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 63e05d4..21a5ca8 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -274,6 +274,21 @@ out_bc:
}
/*
+ * Transfer the do_timer job away from a dying cpu.
+ *
+ * Called with interrupts disabled.
+ */
+static void tick_handover_do_timer(int *cpup)
+{
+ if (*cpup == tick_do_timer_cpu) {
+ int cpu = cpumask_first(cpu_online_mask);
+
+ tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu :
+ TICK_DO_TIMER_NONE;
+ }
+}
+
+/*
* Shutdown an event device on a given cpu:
*
* This is called on a life CPU, when a CPU is dead. So we cannot
@@ -297,13 +312,6 @@ static void tick_shutdown(unsigned int *cpup)
clockevents_exchange_device(dev, NULL);
td->evtdev = NULL;
}
- /* Transfer the do_timer job away from this cpu */
- if (*cpup == tick_do_timer_cpu) {
- int cpu = cpumask_first(cpu_online_mask);
-
- tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu :
- TICK_DO_TIMER_NONE;
- }
spin_unlock_irqrestore(&tick_device_lock, flags);
}
@@ -357,6 +365,10 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason,
tick_broadcast_oneshot_control(reason);
break;
+ case CLOCK_EVT_NOTIFY_CPU_DYING:
+ tick_handover_do_timer(dev);
+ break;
+
case CLOCK_EVT_NOTIFY_CPU_DEAD:
tick_shutdown_broadcast_oneshot(dev);
tick_shutdown_broadcast(dev);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2f32969..7dcf6e9 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -17,6 +17,7 @@
#include <linux/clocksource.h>
#include <linux/kallsyms.h>
#include <linux/seq_file.h>
+#include <linux/suspend.h>
#include <linux/debugfs.h>
#include <linux/hardirq.h>
#include <linux/kthread.h>
@@ -1965,6 +1966,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static atomic_t ftrace_graph_active;
+static struct notifier_block ftrace_suspend_notifier;
int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
{
@@ -2043,6 +2045,27 @@ static int start_graph_tracing(void)
return ret;
}
+/*
+ * Hibernation protection.
+ * The state of the current task is too much unstable during
+ * suspend/restore to disk. We want to protect against that.
+ */
+static int
+ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
+ void *unused)
+{
+ switch (state) {
+ case PM_HIBERNATION_PREPARE:
+ pause_graph_tracing();
+ break;
+
+ case PM_POST_HIBERNATION:
+ unpause_graph_tracing();
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
int register_ftrace_graph(trace_func_graph_ret_t retfunc,
trace_func_graph_ent_t entryfunc)
{
@@ -2050,6 +2073,9 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
mutex_lock(&ftrace_sysctl_lock);
+ ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
+ register_pm_notifier(&ftrace_suspend_notifier);
+
atomic_inc(&ftrace_graph_active);
ret = start_graph_tracing();
if (ret) {
@@ -2075,6 +2101,7 @@ void unregister_ftrace_graph(void)
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
ftrace_graph_entry = ftrace_graph_entry_stub;
ftrace_shutdown(FTRACE_STOP_FUNC_RET);
+ unregister_pm_notifier(&ftrace_suspend_notifier);
mutex_unlock(&ftrace_sysctl_lock);
}
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 8b0daf0..bd38c5c 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -246,7 +246,7 @@ static inline int test_time_stamp(u64 delta)
return 0;
}
-#define BUF_PAGE_SIZE (PAGE_SIZE - sizeof(struct buffer_data_page))
+#define BUF_PAGE_SIZE (PAGE_SIZE - offsetof(struct buffer_data_page, data))
/*
* head_page == tail_page && head == tail then buffer is empty.
@@ -1025,12 +1025,8 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
}
if (next_page == head_page) {
- if (!(buffer->flags & RB_FL_OVERWRITE)) {
- /* reset write */
- if (tail <= BUF_PAGE_SIZE)
- local_set(&tail_page->write, tail);
+ if (!(buffer->flags & RB_FL_OVERWRITE))
goto out_unlock;
- }
/* tail_page has not moved yet? */
if (tail_page == cpu_buffer->tail_page) {
@@ -1105,6 +1101,10 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
return event;
out_unlock:
+ /* reset write */
+ if (tail <= BUF_PAGE_SIZE)
+ local_set(&tail_page->write, tail);
+
__raw_spin_unlock(&cpu_buffer->lock);
local_irq_restore(flags);
return NULL;
@@ -2174,6 +2174,9 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
cpu_buffer->overrun = 0;
cpu_buffer->entries = 0;
+
+ cpu_buffer->write_stamp = 0;
+ cpu_buffer->read_stamp = 0;
}
/**
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c580233..17bb88d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -40,7 +40,7 @@
#define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE)
-unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
+unsigned long __read_mostly tracing_max_latency;
unsigned long __read_mostly tracing_thresh;
/*
@@ -3736,7 +3736,7 @@ static struct notifier_block trace_die_notifier = {
* it if we decide to change what log level the ftrace dump
* should be at.
*/
-#define KERN_TRACE KERN_INFO
+#define KERN_TRACE KERN_EMERG
static void
trace_printk_seq(struct trace_seq *s)
@@ -3770,6 +3770,7 @@ void ftrace_dump(void)
dump_ran = 1;
/* No turning back! */
+ tracing_off();
ftrace_kill();
for_each_tracing_cpu(cpu) {
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 7c2e326..62a78d9 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -380,6 +380,7 @@ static void stop_irqsoff_tracer(struct trace_array *tr)
static void __irqsoff_tracer_init(struct trace_array *tr)
{
+ tracing_max_latency = 0;
irqsoff_trace = tr;
/* make sure that the tracer is visible */
smp_wmb();
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 43586b6..42ae1e7 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -333,6 +333,7 @@ static void stop_wakeup_tracer(struct trace_array *tr)
static int wakeup_tracer_init(struct trace_array *tr)
{
+ tracing_max_latency = 0;
wakeup_trace = tr;
start_wakeup_tracer(tr);
return 0;
generated by cgit v0.10.2 at 2024-11-12 01:01:12 (GMT)