From: Anton Blanchard <anton@samba.org>
Date: Sun, 24 Jul 2011 16:33:12 +0000 (+0000)
Subject: powerpc/numa: Enable SD_WAKE_AFFINE in node definition
X-Git-Tag: v3.2-rc1~34^2~79
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a200d8e44649de2cbb39de95f42ad4ef5dc8dc22;p=pandora-kernel.git

powerpc/numa: Enable SD_WAKE_AFFINE in node definition

When chasing a performance issue on ppc64, I noticed tasks
communicating via a pipe would often end up on different nodes.

It turns out SD_WAKE_AFFINE is not set in our node defition. Commit
9fcd18c9e63e (sched: re-tune balancing) enabled SD_WAKE_AFFINE
in the node definition for x86 and we need a similar change for
ppc64.

I used lmbench lat_ctx and perf bench pipe to verify this fix. Each
benchmark was run 10 times and the average taken.

lmbench lat_ctx:

before:  66565 ops/sec
after:  204700 ops/sec

3.1x faster

perf bench pipe:

before: 5.6570 usecs
after:  1.3470 usecs

4.2x faster

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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