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From: Joonwoo Park <joonwoop@codeaurora.org>
To: tglx@linutronix.de
Cc: sboyd@codeaurora.org, skannan@codeaurora.org,
	linux-kernel@vger.kernel.org,
	Joonwoo Park <joonwoop@codeaurora.org>,
	John Stultz <john.stultz@linaro.org>
Subject: [PATCH 1/2] timer: avoid unnecessary waking up of nohz CPU
Date: Mon, 27 Apr 2015 19:21:49 -0700	[thread overview]
Message-ID: <1430187709-21087-1-git-send-email-joonwoop@codeaurora.org> (raw)

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@linutronix.de>
CC: John Stultz <john.stultz@linaro.org>
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
---
 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))
 		wake_up_nohz_cpu(base->cpu);
 }
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation


             reply	other threads:[~2015-04-28  2:21 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-28  2:21 Joonwoo Park [this message]
2015-04-28 21:59 ` [PATCH 1/2] timer: avoid unnecessary waking up of nohz CPU Stephen Boyd
2015-04-29  2:41 ` Viresh Kumar
2015-05-05  8:42 ` [tip:timers/core] timer: Use timer->base for flag checks tip-bot for Joonwoo Park

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