Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7d976699 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

sched/migration: Move CPU_ONLINE into scheduler state 



The alleged requirement that the migration notifier has a lower priority than
perf is completely undocumented and there is no indication at all that this is
true. perf does not even handle the CPU_ONLINE notification and perf really
has nothing to do with migration.

Move the CPU_ONLINE code into the sched_activate_cpu() state callback.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160310120025.421743581@linutronix.de


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent e9cd8fa4

kernel/sched/core.c

+22 −11
Original line number Diff line number Diff line
@@ -5424,17 +5424,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) 


	switch (action & ~CPU_TASKS_FROZEN) {



	case CPU_ONLINE:

		/* Update our root-domain */

		raw_spin_lock_irqsave(&rq->lock, flags);

		if (rq->rd) {

			BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));



			set_rq_online(rq);

		}

		raw_spin_unlock_irqrestore(&rq->lock, flags);

		break;



#ifdef CONFIG_HOTPLUG_CPU

	case CPU_DYING:

		sched_ttwu_pending();
@@ -7090,12 +7079,34 @@ static int cpuset_cpu_inactive(unsigned int cpu) 


int sched_cpu_activate(unsigned int cpu)

{

	struct rq *rq = cpu_rq(cpu);

	unsigned long flags;



	set_cpu_active(cpu, true);



	if (sched_smp_initialized) {

		sched_domains_numa_masks_set(cpu);

		cpuset_cpu_active();

	}



	/*

	 * Put the rq online, if not already. This happens:

	 *

	 * 1) In the early boot process, because we build the real domains

	 *    after all cpus have been brought up.

	 *

	 * 2) At runtime, if cpuset_cpu_active() fails to rebuild the

	 *    domains.

	 */

	raw_spin_lock_irqsave(&rq->lock, flags);

	if (rq->rd) {

		BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));

		set_rq_online(rq);

	}

	raw_spin_unlock_irqrestore(&rq->lock, flags);



	update_max_interval();



	return 0;

}