From: Mike Galbraith <efault@gmx.de>
Date: Mon, 2 Nov 2009 19:36:51 +0000 (+0100)
Subject: sched: Disable SD_PREFER_LOCAL at node level
X-Git-Tag: v2.6.32-rc7~73^2~1
X-Git-Url: http://git.cascardo.eti.br/?a=commitdiff_plain;h=6b9de613ae9c79b637e070136585dde029578065;p=cascardo%2Flinux.git

sched: Disable SD_PREFER_LOCAL at node level

Yanmin Zhang reported that SD_PREFER_LOCAL induces an order of
magnitude increase in select_task_rq_fair() overhead while
running heavy wakeup benchmarks (tbench and vmark).

Since SD_BALANCE_WAKE is off at node level, turn SD_PREFER_LOCAL
off as well pending further investigation.

Reported-by: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index d823c245f63b..40e37b10c6c0 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -143,7 +143,7 @@ extern unsigned long node_remap_size[];
 				| 1*SD_BALANCE_FORK			\
 				| 0*SD_BALANCE_WAKE			\
 				| 1*SD_WAKE_AFFINE			\
-				| 1*SD_PREFER_LOCAL			\
+				| 0*SD_PREFER_LOCAL			\
 				| 0*SD_SHARE_CPUPOWER			\
 				| 0*SD_POWERSAVINGS_BALANCE		\
 				| 0*SD_SHARE_PKG_RESOURCES		\