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Diffstat (limited to 'kernel/sched/fair.c')
-rw-r--r--kernel/sched/fair.c44
1 files changed, 36 insertions, 8 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8e42de9105f..7c6414fc669 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3130,8 +3130,10 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
}
#define LBF_ALL_PINNED 0x01
-#define LBF_NEED_BREAK 0x02
-#define LBF_ABORT 0x04
+#define LBF_NEED_BREAK 0x02 /* clears into HAD_BREAK */
+#define LBF_HAD_BREAK 0x04
+#define LBF_HAD_BREAKS 0x0C /* count HAD_BREAKs overflows into ABORT */
+#define LBF_ABORT 0x10
/*
* can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
@@ -4508,7 +4510,9 @@ redo:
goto out_balanced;
if (lb_flags & LBF_NEED_BREAK) {
- lb_flags &= ~LBF_NEED_BREAK;
+ lb_flags += LBF_HAD_BREAK - LBF_NEED_BREAK;
+ if (lb_flags & LBF_ABORT)
+ goto out_balanced;
goto redo;
}
@@ -4862,6 +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;
@@ -4900,6 +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;
@@ -4910,6 +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);
@@ -5066,11 +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
@@ -5586,6 +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 */