Commit e73e85f0 authored Oct 10, 2015 by Oleg Nesterov Committed by Ingo Molnar Oct 20, 2015

sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS

If CONFIG_CPUSETS=n then "case cpuset" changes the state and runs
the already failed for_each_cpu() loop again for no reason.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20151010185315.GA24100@redhat.com

Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 62694cd5

kernel/sched/core.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -1580,13 +1580,15 @@ static int select_fallback_rq(int cpu, struct task_struct *p)
		goto out;
		}

		/* No more Mr. Nice Guy. */
		switch (state) {
		case cpuset:
		/* No more Mr. Nice Guy. */
		if (IS_ENABLED(CONFIG_CPUSETS)) {
		cpuset_cpus_allowed_fallback(p);
		state = possible;
		break;

		}
		/* fall-through */
		case possible:
		do_set_cpus_allowed(p, cpu_possible_mask);
		state = fail;