[tip:sched/urgent] sched: Disable SD_PREFER_LOCAL at node level

tip-bot for Mike Galbraith
2009-11-03T07:04:23Z

Commit-ID: 6b9de613ae9c79b637e070136585dde029578065
Gitweb: http://git.kernel.org/tip/6b9de613ae9c79b637e070136585dde029578065
Author: Mike Galbraith <efault@gmx.de>
AuthorDate: Mon, 2 Nov 2009 20:36:51 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 3 Nov 2009 07:24:07 +0100

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>
---
arch/x86/include/asm/topology.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index d823c24..40e37b1 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 \