From 6201b4d61fbf194df6371fb3376c5026cb8f5eec Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Tue, 18 Mar 2014 16:26:07 +0530 Subject: [PATCH] timer: Remove code redundancy while calling get_nohz_timer_target() There are only two users of get_nohz_timer_target(): timer and hrtimer. Both call it under same circumstances, i.e. #ifdef CONFIG_NO_HZ_COMMON if (!pinned && get_sysctl_timer_migration() && idle_cpu(this_cpu)) return get_nohz_timer_target(); #endif So, it makes more sense to get all this as part of get_nohz_timer_target() instead of duplicating code at two places. For this another parameter is required to be passed to this routine, pinned. Signed-off-by: Viresh Kumar Cc: linaro-kernel@lists.linaro.org Cc: fweisbec@gmail.com Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/1e1b53537217d58d48c2d7a222a9c3ac47d5b64c.1395140107.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner --- include/linux/sched.h | 6 +++++- kernel/hrtimer.c | 15 +-------------- kernel/sched/core.c | 5 ++++- kernel/timer.c | 7 +------ 4 files changed, 11 insertions(+), 22 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 68a0e84463a0..6f6c56f63c68 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -291,10 +291,14 @@ extern int runqueue_is_locked(int cpu); #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON) extern void nohz_balance_enter_idle(int cpu); extern void set_cpu_sd_state_idle(void); -extern int get_nohz_timer_target(void); +extern int get_nohz_timer_target(int pinned); #else static inline void nohz_balance_enter_idle(int cpu) { } static inline void set_cpu_sd_state_idle(void) { } +static inline int get_nohz_timer_target(int pinned) +{ + return smp_processor_id(); +} #endif /* diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 09094361dce5..d55092ceee29 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -168,19 +168,6 @@ struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer, } } - -/* - * Get the preferred target CPU for NOHZ - */ -static int hrtimer_get_target(int this_cpu, int pinned) -{ -#ifdef CONFIG_NO_HZ_COMMON - if (!pinned && get_sysctl_timer_migration() && idle_cpu(this_cpu)) - return get_nohz_timer_target(); -#endif - return this_cpu; -} - /* * With HIGHRES=y we do not migrate the timer when it is expiring * before the next event on the target cpu because we cannot reprogram @@ -214,7 +201,7 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base, struct hrtimer_clock_base *new_base; struct hrtimer_cpu_base *new_cpu_base; int this_cpu = smp_processor_id(); - int cpu = hrtimer_get_target(this_cpu, pinned); + int cpu = get_nohz_timer_target(pinned); int basenum = base->index; again: diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b46131ef6aab..c0339e206cc2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -555,12 +555,15 @@ void resched_cpu(int cpu) * selecting an idle cpu will add more delays to the timers than intended * (as that cpu's timer base may not be uptodate wrt jiffies etc). */ -int get_nohz_timer_target(void) +int get_nohz_timer_target(int pinned) { int cpu = smp_processor_id(); int i; struct sched_domain *sd; + if (pinned || !get_sysctl_timer_migration() || !idle_cpu(cpu)) + return cpu; + rcu_read_lock(); for_each_domain(cpu, sd) { for_each_cpu(i, sched_domain_span(sd)) { diff --git a/kernel/timer.c b/kernel/timer.c index 8e503fec1fba..1d35ddadc045 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -760,12 +760,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, debug_activate(timer, expires); - cpu = smp_processor_id(); - -#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP) - if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu)) - cpu = get_nohz_timer_target(); -#endif + cpu = get_nohz_timer_target(pinned); new_base = per_cpu(tvec_bases, cpu); if (base != new_base) { -- 2.20.1