From: Mike Galbraith <efault@gmx.de>
Date: Tue, 27 Oct 2009 14:35:38 +0000 (+0100)
Subject: sched: Check for an idle shared cache in select_task_rq_fair()
X-Git-Tag: v2.6.33-rc1~398^2~23
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a1f84a3ab8e002159498814eaa7e48c33752b04b;p=pandora-kernel.git

sched: Check for an idle shared cache in select_task_rq_fair()

When waking affine, check for an idle shared cache, and if
found, wake to that CPU/sibling instead of the waker's CPU.

This improves pgsql+oltp ramp up by roughly 8%. Possibly more
for other loads, depending on overlap. The trade-off is a
roughly 1% peak downturn if tasks are truly synchronous.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@kernel.org>
LKML-Reference: <1256654138.17752.7.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

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