Messages in this thread Patch in this message | | | Date | Mon, 25 Jul 2011 12:33:12 +1000 | From | Anton Blanchard <> | Subject | [PATCH 1/5] powerpc/numa: Enable SD_WAKE_AFFINE in node definition |
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When chasing a performance issue on ppc64, I noticed tasks communicating via a pipe would often end up on different nodes.
It turns out SD_WAKE_AFFINE is not set in our node defition. Commit 9fcd18c9e63e (sched: re-tune balancing) enabled SD_WAKE_AFFINE in the node definition for x86 and we need a similar change for ppc64.
I used lmbench lat_ctx and perf bench pipe to verify this fix. Each benchmark was run 10 times and the average taken.
lmbench lat_ctx:
before: 66565 ops/sec after: 204700 ops/sec
3.1x faster
perf bench pipe:
before: 5.6570 usecs after: 1.3470 usecs
4.2x faster
Signed-off-by: Anton Blanchard <anton@samba.org> ---
Cc-ing arch maintainers who might need to look at their SD_NODE_INIT definitions
Index: linux-2.6-work/arch/powerpc/include/asm/topology.h =================================================================== --- linux-2.6-work.orig/arch/powerpc/include/asm/topology.h 2011-07-18 16:24:55.639949552 +1000 +++ linux-2.6-work/arch/powerpc/include/asm/topology.h 2011-07-18 16:25:02.630074557 +1000 @@ -73,7 +73,7 @@ static inline int pcibus_to_node(struct | 1*SD_BALANCE_EXEC \ | 1*SD_BALANCE_FORK \ | 0*SD_BALANCE_WAKE \ - | 0*SD_WAKE_AFFINE \ + | 1*SD_WAKE_AFFINE \ | 0*SD_PREFER_LOCAL \ | 0*SD_SHARE_CPUPOWER \ | 0*SD_POWERSAVINGS_BALANCE \
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