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Commit 916671c0 authored Nov 22, 2011 by Mike Galbraith Committed by Ingo Molnar Dec 06, 2011

sched: Set skip_clock_update in yield_task_fair()



This is another case where we are on our way to schedule(),
so can save a useless clock update and resulting microscopic
vruntime update.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1321971686.6855.18.camel@marge.simson.net


Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 76854c7e

kernel/sched/core.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -4547,6 +4547,13 @@ again:
		*/
		if (preempt && rq != p_rq)
		resched_task(p_rq->curr);
		} else {
		/*
		* We might have set it in task_yield_fair(), but are
		* not going to schedule(), so don't want to skip
		* the next update.
		*/
		rq->skip_clock_update = 0;
		}

		out:

kernel/sched/fair.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -3075,6 +3075,12 @@ static void yield_task_fair(struct rq *rq)
		* Update run-time statistics of the 'current'.
		*/
		update_curr(cfs_rq);
		/*
		* Tell update_rq_clock() that we've just updated,
		* so we don't do microscopic update in schedule()
		* and double the fastpath cost.
		*/
		rq->skip_clock_update = 1;
		}

		set_skip_buddy(se);