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-rw-r--r--include/linux/sched.h4
-rw-r--r--kernel/sched/core.c20
-rw-r--r--kernel/timer.c12
3 files changed, 27 insertions, 9 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 9004f6e19ea..10626e2ee68 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1851,9 +1851,9 @@ static inline void idle_task_exit(void) {}
#endif
#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
-extern void wake_up_idle_cpu(int cpu);
+extern void wake_up_nohz_cpu(int cpu);
#else
-static inline void wake_up_idle_cpu(int cpu) { }
+static inline void wake_up_nohz_cpu(int cpu) { }
#endif
#ifdef CONFIG_SCHED_AUTOGROUP
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 849deb96e61..e91ee589f79 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -587,7 +587,7 @@ unlock:
* account when the CPU goes back to idle and evaluates the timer
* wheel for the next timer event.
*/
-void wake_up_idle_cpu(int cpu)
+static void wake_up_idle_cpu(int cpu)
{
struct rq *rq = cpu_rq(cpu);
@@ -617,6 +617,24 @@ void wake_up_idle_cpu(int cpu)
smp_send_reschedule(cpu);
}
+static bool wake_up_extended_nohz_cpu(int cpu)
+{
+ if (tick_nohz_extended_cpu(cpu)) {
+ if (cpu != smp_processor_id() ||
+ tick_nohz_tick_stopped())
+ smp_send_reschedule(cpu);
+ return true;
+ }
+
+ return false;
+}
+
+void wake_up_nohz_cpu(int cpu)
+{
+ if (!wake_up_extended_nohz_cpu(cpu))
+ wake_up_idle_cpu(cpu);
+}
+
static inline bool got_nohz_idle_kick(void)
{
int cpu = smp_processor_id();
diff --git a/kernel/timer.c b/kernel/timer.c
index dbf7a78a1ef..4e3040b40d1 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -930,14 +930,14 @@ void add_timer_on(struct timer_list *timer, int cpu)
debug_activate(timer, timer->expires);
internal_add_timer(base, timer);
/*
- * Check whether the other CPU is idle and needs to be
- * triggered to reevaluate the timer wheel when nohz is
- * active. We are protected against the other CPU fiddling
+ * Check whether the other CPU is in dynticks mode and needs
+ * to be triggered to reevaluate the timer wheel.
+ * We are protected against the other CPU fiddling
* with the timer by holding the timer base lock. This also
- * makes sure that a CPU on the way to idle can not evaluate
- * the timer wheel.
+ * makes sure that a CPU on the way to stop its tick can not
+ * evaluate the timer wheel.
*/
- wake_up_idle_cpu(cpu);
+ wake_up_nohz_cpu(cpu);
spin_unlock_irqrestore(&base->lock, flags);
}
EXPORT_SYMBOL_GPL(add_timer_on);