Commit f1cd0858 authored Apr 23, 2013 by Joonsoo Kim Committed by Ingo Molnar Apr 24, 2013

sched: Change position of resched_cpu() in load_balance()



cur_ld_moved is reset if env.flags hit LBF_NEED_BREAK.
So, there is possibility that we miss doing resched_cpu().
Correct it as changing position of resched_cpu()
before checking LBF_NEED_BREAK.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: Jason Low <jason.low2@hp.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1366705662-3587-2-git-send-email-iamjoonsoo.kim@lge.com


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

parent 642dbc39

kernel/sched/fair.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -5080,17 +5080,17 @@ static int load_balance(int this_cpu, struct rq *this_rq,
		double_rq_unlock(env.dst_rq, busiest);
		local_irq_restore(flags);

		if (env.flags & LBF_NEED_BREAK) {
		env.flags &= ~LBF_NEED_BREAK;
		goto more_balance;
		}

		/*
		* some other cpu did the load balance for us.
		*/
		if (cur_ld_moved && env.dst_cpu != smp_processor_id())
		resched_cpu(env.dst_cpu);

		if (env.flags & LBF_NEED_BREAK) {
		env.flags &= ~LBF_NEED_BREAK;
		goto more_balance;
		}

		/*
		* Revisit (affine) tasks on src_cpu that couldn't be moved to
		* us and move them to an alternate dst_cpu in our sched_group