linux-kernel - [PATCH V3 2/7] timer: hrtimer: Don't check idle_cpu() before calling get_nohz_timer

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Message-Id: <b5639020972e5321269d403c65e9b62ba8236bab.1363617402.git.viresh.kumar@linaro.org>
Date:	Mon, 18 Mar 2013 20:53:24 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	pjt@...gle.com, paul.mckenney@...aro.org, tglx@...utronix.de,
	tj@...nel.org, suresh.b.siddha@...el.com, venki@...gle.com,
	mingo@...hat.com, peterz@...radead.org, rostedt@...dmis.org
Cc:	linaro-kernel@...ts.linaro.org, robin.randhawa@....com,
	Steve.Bannister@....com, Liviu.Dudau@....com,
	charles.garcia-tobin@....com, Arvind.Chauhan@....com,
	linux-rt-users@...r.kernel.org, linux-kernel@...r.kernel.org,
	Viresh Kumar <viresh.kumar@...aro.org>
Subject: [PATCH V3 2/7] timer: hrtimer: Don't check idle_cpu() before calling get_nohz_timer_target()

Check for current cpu's idleness is already done in implementation of
sched_select_cpu() which is called by get_nohz_timer_target(). So, no need to
call idle_cpu() twice, once from sched_select_cpu() and once from timer and
hrtimer before calling get_nohz_timer_target().

This patch removes calls to idle_cpu() from timer and hrtimer.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 kernel/hrtimer.c | 2 +-
 kernel/timer.c   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index cc47812..c56668d 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -161,7 +161,7 @@ struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
 static int hrtimer_get_target(int this_cpu, int pinned)
 {
 #ifdef CONFIG_NO_HZ
-	if (!pinned && get_sysctl_timer_migration() && idle_cpu(this_cpu))
+	if (!pinned && get_sysctl_timer_migration())
 		return get_nohz_timer_target();
 #endif
 	return this_cpu;
diff --git a/kernel/timer.c b/kernel/timer.c
index dbf7a78..83a0d3c 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -739,7 +739,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
 	cpu = smp_processor_id();
 
 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
-	if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu))
+	if (!pinned && get_sysctl_timer_migration())
 		cpu = get_nohz_timer_target();
 #endif
 	new_base = per_cpu(tvec_bases, cpu);
-- 
1.7.12.rc2.18.g61b472e

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