Check for current cpu's idleness 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.
This also reduces an extra call to smp_processor_id() when
get_nohz_timer_target() is called.
Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
---
kernel/hrtimer.c | 2 +-
kernel/timer.c | 8 +++++---
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 6db7a5e..74bdaf6 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -159,7 +159,7 @@ 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 367d008..1170ece 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -735,11 +735,13 @@ __mod_timer(struct timer_list *timer, unsigned long
expires,
debug_activate(timer, 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();
+ else
+ cpu = smp_processor_id();
+#else
+ cpu = smp_processor_id();
#endif
new_base = per_cpu(tvec_bases, cpu);
--
1.7.12.rc2.18.g61b472e
--
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