The following commit has been merged in the linux branch: commit 6b9de613ae9c79b637e070136585dde029578065 Author: Mike Galbraith efault@gmx.de Date: Mon Nov 2 20:36:51 2009 +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

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 \