diff options
| -rw-r--r-- | kernel/sched/fair.c | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 84adb2d..7c6414f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4866,6 +4866,15 @@ static void nohz_balancer_kick(int cpu) return; } +static inline void clear_nohz_tick_stopped(int cpu) +{ + if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) { + cpumask_clear_cpu(cpu, nohz.idle_cpus_mask); + atomic_dec(&nohz.nr_cpus); + clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)); + } +} + static inline void set_cpu_sd_state_busy(void) { struct sched_domain *sd; @@ -4904,6 +4913,12 @@ void select_nohz_load_balancer(int stop_tick) { 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; @@ -4914,6 +4929,18 @@ void select_nohz_load_balancer(int stop_tick) } return; } + +static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_DYING: + clear_nohz_tick_stopped(smp_processor_id()); + return NOTIFY_OK; + default: + return NOTIFY_DONE; + } +} #endif static DEFINE_SPINLOCK(balancing); @@ -5070,11 +5097,7 @@ 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(); - if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) { - clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)); - cpumask_clear_cpu(cpu, nohz.idle_cpus_mask); - atomic_dec(&nohz.nr_cpus); - } + clear_nohz_tick_stopped(cpu); /* * None are in tickless mode and hence no need for NOHZ idle load @@ -5590,6 +5613,7 @@ __init void init_sched_fair_class(void) #ifdef CONFIG_NO_HZ zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); + cpu_notifier(sched_ilb_notifier, 0); #endif #endif /* SMP */ |