Messages in this thread Patch in this message | | | Date | Fri, 4 Sep 2009 10:25:43 GMT | From | tip-bot for Ingo Molnar <> | Subject | [tip:sched/balancing] sched: Turn on SD_WAKE_IDLE for 'close' domains |
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Commit-ID: e54c7073fae0683b90b3157e97142202c7334b79 Gitweb: http://git.kernel.org/tip/e54c7073fae0683b90b3157e97142202c7334b79 Author: Ingo Molnar <mingo@elte.hu> AuthorDate: Fri, 4 Sep 2009 11:38:07 +0200 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Fri, 4 Sep 2009 12:17:06 +0200
sched: Turn on SD_WAKE_IDLE for 'close' domains
Turn it on for the thread, core and cpu domain defaults.
Same argument as for NEWIDLE: we want to err on the side of over-balancing, and mute the effect of that when it hurts a workload.
On a NUMA box (4x4) i get better CPU utilization:
Performance counter stats for './hackbench 10' (10 runs):
Before: 2124.478000 task-clock-msecs # 12.196 CPUs ( +- 0.614% ) After: 2232.558805 task-clock-msecs # 12.601 CPUs ( +- 0.852% )
It's probably not worth turning it on for the NUMA domain though, as even on this fast-NUMA box it's break-even in terms of cost versus improvement:
After #2: 2288.062034 task-clock-msecs # 12.909 CPUs ( +- 0.864% )
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- include/linux/topology.h | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/topology.h b/include/linux/topology.h index 66774fd..f13ff3a 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -95,7 +95,7 @@ int arch_update_cpu_topology(void); | 1*SD_BALANCE_NEWIDLE \ | 1*SD_BALANCE_EXEC \ | 1*SD_BALANCE_FORK \ - | 0*SD_WAKE_IDLE \ + | 1*SD_WAKE_IDLE \ | 1*SD_WAKE_AFFINE \ | 1*SD_WAKE_BALANCE \ | 1*SD_SHARE_CPUPOWER \ @@ -129,7 +129,7 @@ int arch_update_cpu_topology(void); | 1*SD_BALANCE_NEWIDLE \ | 1*SD_BALANCE_EXEC \ | 1*SD_BALANCE_FORK \ - | 0*SD_WAKE_IDLE \ + | 1*SD_WAKE_IDLE \ | 1*SD_WAKE_AFFINE \ | 1*SD_WAKE_BALANCE \ | 0*SD_SHARE_CPUPOWER \ @@ -163,7 +163,7 @@ int arch_update_cpu_topology(void); | 1*SD_BALANCE_NEWIDLE \ | 1*SD_BALANCE_EXEC \ | 1*SD_BALANCE_FORK \ - | 0*SD_WAKE_IDLE \ + | 1*SD_WAKE_IDLE \ | 0*SD_WAKE_AFFINE \ | 1*SD_WAKE_BALANCE \ | 0*SD_SHARE_CPUPOWER \
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