sched/fair: Make ilb_notifier an explicit call

No need for an extra notifier.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160310120025.693720241@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/sched/core.c

@@ -7131,6 +7131,7 @@ 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;
 }
 #endif

kernel/sched/fair.c

@@ -7711,7 +7711,7 @@ 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)))) {
 		/*
@@ -7784,18 +7784,6 @@ 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);
@@ -8600,7 +8588,6 @@ __init void init_sched_fair_class(void)
 #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 */
 

kernel/sched/sched.h

@@ -1743,6 +1743,10 @@ 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