From c1cc017c59c44d9ede7003631c43adc0cfdce2f9 Mon Sep 17 00:00:00 2001 From: Alex Shi Date: Mon, 10 Sep 2012 15:10:58 +0800 Subject: [PATCH] sched/nohz: Clean up select_nohz_load_balancer() There is no load_balancer to be selected now. It just sets the state of the nohz tick to stop. So rename the function, pass the 'cpu' as a parameter and then remove the useless call from tick_nohz_restart_sched_tick(). [ s/set_nohz_tick_stopped/nohz_balance_enter_idle/g s/clear_nohz_tick_stopped/nohz_balance_exit_idle/g ] Signed-off-by: Alex Shi Acked-by: Suresh Siddha Cc: Venkatesh Pallipadi Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1347261059-24747-1-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar --- include/linux/sched.h | 4 ++-- kernel/sched/fair.c | 25 ++++++++++--------------- kernel/time/tick-sched.c | 3 +-- 3 files changed, 13 insertions(+), 19 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 60e5e38..8c38df0 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -273,11 +273,11 @@ extern void init_idle_bootup_task(struct task_struct *idle); extern int runqueue_is_locked(int cpu); #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ) -extern void select_nohz_load_balancer(int stop_tick); +extern void nohz_balance_enter_idle(int cpu); extern void set_cpu_sd_state_idle(void); extern int get_nohz_timer_target(void); #else -static inline void select_nohz_load_balancer(int stop_tick) { } +static inline void nohz_balance_enter_idle(int cpu) { } static inline void set_cpu_sd_state_idle(void) { } #endif diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9ae3a5b..de596a2 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4603,7 +4603,7 @@ static void nohz_balancer_kick(int cpu) return; } -static inline void clear_nohz_tick_stopped(int cpu) +static inline void nohz_balance_exit_idle(int cpu) { if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) { cpumask_clear_cpu(cpu, nohz.idle_cpus_mask); @@ -4643,28 +4643,23 @@ void set_cpu_sd_state_idle(void) } /* - * This routine will record that this cpu is going idle with tick stopped. + * This routine will record that the cpu is going idle with tick stopped. * This info will be used in performing idle load balancing in the future. */ -void select_nohz_load_balancer(int stop_tick) +void nohz_balance_enter_idle(int cpu) { - int cpu = smp_processor_id(); - /* * If this cpu is going down, then nothing needs to be done. */ if (!cpu_active(cpu)) return; - if (stop_tick) { - if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu))) - return; + if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu))) + return; - cpumask_set_cpu(cpu, nohz.idle_cpus_mask); - atomic_inc(&nohz.nr_cpus); - set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)); - } - return; + cpumask_set_cpu(cpu, nohz.idle_cpus_mask); + atomic_inc(&nohz.nr_cpus); + set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)); } static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb, @@ -4672,7 +4667,7 @@ static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb, { switch (action & ~CPU_TASKS_FROZEN) { case CPU_DYING: - clear_nohz_tick_stopped(smp_processor_id()); + nohz_balance_exit_idle(smp_processor_id()); return NOTIFY_OK; default: return NOTIFY_DONE; @@ -4833,7 +4828,7 @@ static inline int nohz_kick_needed(struct rq *rq, int cpu) * busy tick after returning from idle, we will update the busy stats. */ set_cpu_sd_state_busy(); - clear_nohz_tick_stopped(cpu); + nohz_balance_exit_idle(cpu); /* * None are in tickless mode and hence no need for NOHZ idle load diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 3a9e5d5..1a5ee90 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -372,7 +372,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, * the scheduler tick in nohz_restart_sched_tick. */ if (!ts->tick_stopped) { - select_nohz_load_balancer(1); + nohz_balance_enter_idle(cpu); calc_load_enter_idle(); ts->last_tick = hrtimer_get_expires(&ts->sched_timer); @@ -569,7 +569,6 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now) static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now) { /* Update jiffies first */ - select_nohz_load_balancer(0); tick_do_update_jiffies64(now); update_cpu_load_nohz(); -- 2.7.4