summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--kernel/sched/core.c28
1 files changed, 23 insertions, 5 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index bdb7aa67baef..1428c7cebe2f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2151,12 +2151,15 @@ void wake_up_new_task(struct task_struct *p)
#ifdef CONFIG_PREEMPT_NOTIFIERS
+static struct static_key preempt_notifier_key = STATIC_KEY_INIT_FALSE;
+
/**
* preempt_notifier_register - tell me when current is being preempted & rescheduled
* @notifier: notifier struct to register
*/
void preempt_notifier_register(struct preempt_notifier *notifier)
{
+ static_key_slow_inc(&preempt_notifier_key);
hlist_add_head(&notifier->link, &current->preempt_notifiers);
}
EXPORT_SYMBOL_GPL(preempt_notifier_register);
@@ -2170,10 +2173,11 @@ EXPORT_SYMBOL_GPL(preempt_notifier_register);
void preempt_notifier_unregister(struct preempt_notifier *notifier)
{
hlist_del(&notifier->link);
+ static_key_slow_dec(&preempt_notifier_key);
}
EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
-static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+static void __fire_sched_in_preempt_notifiers(struct task_struct *curr)
{
struct preempt_notifier *notifier;
@@ -2181,9 +2185,15 @@ static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
notifier->ops->sched_in(notifier, raw_smp_processor_id());
}
+static __always_inline void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+{
+ if (static_key_false(&preempt_notifier_key))
+ __fire_sched_in_preempt_notifiers(curr);
+}
+
static void
-fire_sched_out_preempt_notifiers(struct task_struct *curr,
- struct task_struct *next)
+__fire_sched_out_preempt_notifiers(struct task_struct *curr,
+ struct task_struct *next)
{
struct preempt_notifier *notifier;
@@ -2191,13 +2201,21 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr,
notifier->ops->sched_out(notifier, next);
}
+static __always_inline void
+fire_sched_out_preempt_notifiers(struct task_struct *curr,
+ struct task_struct *next)
+{
+ if (static_key_false(&preempt_notifier_key))
+ __fire_sched_out_preempt_notifiers(curr, next);
+}
+
#else /* !CONFIG_PREEMPT_NOTIFIERS */
-static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+static inline void fire_sched_in_preempt_notifiers(struct task_struct *curr)
{
}
-static void
+static inline void
fire_sched_out_preempt_notifiers(struct task_struct *curr,
struct task_struct *next)
{