[patch 14/15] sched/fair: Make ilb_notifier an explicit call

From: Thomas Gleixner
Date: Thu Mar 10 2016 - 07:06:44 EST


No need for an extra notifier.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/sched/core.c | 1 +
kernel/sched/fair.c | 15 +--------------
kernel/sched/sched.h | 4 ++++
3 files changed, 6 insertions(+), 14 deletions(-)

Index: b/kernel/sched/core.c
===================================================================
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7363,6 +7363,7 @@ int sched_cpu_dying(unsigned int cpu)
raw_spin_unlock_irqrestore(&rq->lock, flags);
calc_load_migrate(rq);
update_max_interval();
+ nohz_balance_exit_idle(cpu);
return 0;
}

Index: b/kernel/sched/fair.c
===================================================================
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7602,7 +7602,7 @@ static void nohz_balancer_kick(void)
return;
}

-static inline void nohz_balance_exit_idle(int cpu)
+void nohz_balance_exit_idle(unsigned int cpu)
{
if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
/*
@@ -7675,18 +7675,6 @@ void nohz_balance_enter_idle(int cpu)
atomic_inc(&nohz.nr_cpus);
set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
}
-
-static int sched_ilb_notifier(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
-{
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_DYING:
- nohz_balance_exit_idle(smp_processor_id());
- return NOTIFY_OK;
- default:
- return NOTIFY_DONE;
- }
-}
#endif

static DEFINE_SPINLOCK(balancing);
@@ -8486,7 +8474,6 @@ void show_numa_stats(struct task_struct
#ifdef CONFIG_NO_HZ_COMMON
nohz.next_balance = jiffies;
zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT);
- cpu_notifier(sched_ilb_notifier, 0);
#endif
#endif /* SMP */

Index: b/kernel/sched/sched.h
===================================================================
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1688,6 +1688,10 @@ enum rq_nohz_flag_bits {
};

#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
+
+extern void nohz_balance_exit_idle(unsigned int cpu);
+#else
+static inline void nohz_balance_exit_idle(unsigned int cpu) { }
#endif

#ifdef CONFIG_IRQ_TIME_ACCOUNTING