Commit 7aff2e3a authored Sep 15, 2013 by Vladimir Davydov Committed by Ingo Molnar Sep 20, 2013

sched/balancing: Prevent the reselection of a previous env.dst_cpu if some tasks are pinned

Currently new_dst_cpu is prevented from being reselected actually, not
dst_cpu. This can result in attempting to pull tasks to this_cpu twice.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/281f59b6e596c718dd565ad267fc38f5b8e5c995.1379265590.git.vdavydov@parallels.com

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

parent 40a0c68c

kernel/sched/fair.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -5261,15 +5261,15 @@ more_balance:
		*/
		if ((env.flags & LBF_DST_PINNED) && env.imbalance > 0) {

		/* Prevent to re-select dst_cpu via env's cpus */
		cpumask_clear_cpu(env.dst_cpu, env.cpus);

		env.dst_rq = cpu_rq(env.new_dst_cpu);
		env.dst_cpu = env.new_dst_cpu;
		env.flags &= ~LBF_DST_PINNED;
		env.loop = 0;
		env.loop_break = sched_nr_migrate_break;

		/* Prevent to re-select dst_cpu via env's cpus */
		cpumask_clear_cpu(env.dst_cpu, env.cpus);

		/*
		* Go back to "more_balance" rather than "redo" since we
		* need to continue with same src_cpu.