[PATCH 1/2] timer: avoid unnecessary waking up of nohz CPU

From: Joonwoo Park
Date: Mon Apr 27 2015 - 22:22:00 EST

At present, internal_add_timer() examines flags with 'base' which doesn't
contain flags. Examine with 'timer->base' to avoid unnecessary waking up
of nohz CPU when timer base has TIMER_DEFERRABLE.

CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CC: John Stultz <john.stultz@xxxxxxxxxx>
Signed-off-by: Joonwoo Park <joonwoop@xxxxxxxxxxxxxx>
kernel/time/timer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 2ece3aa..e5d5733c 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -434,7 +434,7 @@ static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
* require special care against races with idle_cpu(), lets deal
* with that later.
- if (!tbase_get_deferrable(base) || tick_nohz_full_cpu(base->cpu))
+ if (!tbase_get_deferrable(timer->base) || tick_nohz_full_cpu(base->cpu))

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