sched: Micro-optimize the smart wake-affine logic

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Smart wake-affine is using node-size as the factor currently, but the overhead
of the mask operation is high.

Thus, this patch introduce the 'sd_llc_size' percpu variable, which will record
the highest cache-share domain size, and make it to be the new factor, in order
to reduce the overhead and make it more reasonable.

Tested-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Tested-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/51D5008E.6030102@linux.vnet.ibm.com
[ Tidied up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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This commit is contained in:

Peter Zijlstra 2013-07-04 12:56:46 +08:00 • committed by Ingo Molnar

parent 62470419e9

commit 7d9ffa8961

3 changed files with 8 additions and 2 deletions

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7

kernel/sched/core.c

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2

kernel/sched/fair.c

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1

kernel/sched/sched.h

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