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

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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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Mike Galbraith 2009-10-27 15:35:38 +01:00 • committed by Ingo Molnar

parent acc3f5d7ca

commit a1f84a3ab8

1 changed files with 29 additions and 4 deletions

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kernel/sched_fair.c

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