From: Ken Chen <kenchen@google.com>
Date: Mon, 8 Dec 2008 02:47:37 +0000 (-0800)
Subject: sched: fix sd_parent_degenerate on non-numa smp machine
X-Git-Tag: v2.6.29-rc1~585^2~11
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5436499e6098759c2340f8b906ea52f993dc4efb;p=pandora-kernel.git

sched: fix sd_parent_degenerate on non-numa smp machine

Impact: optimize the sched domains tree some more

The addition of SD_SERIALIZE flag added to SD_NODE_INIT prevented top level
dummy numa sched_domain to be properly degenerated on non-numa smp machine.
The reason is that in sd_parent_degenerate(), it found that the child and
parent does not have comon sched_domain flags due to SD_SERIALIZE.  However,
for non-numa smp box, the top level is a dummy with a single sched_group.

Filter out SD_SERIALIZE if it is on non-numa machine to properly degenerate
top level node sched_domain.  this will cut back some of the sd domain walk
in the load balancer code.

Signed-off-by: Ken Chen <kenchen@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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