[PATCH] sched/numa: recovered SD_PERFER_SIBLING on CPU domain
From: Alex Shi
Date: Fri Jul 20 2012 - 02:19:41 EST
commit 8e7fbcbc22c(sched: Remove stale power aware scheduling remnants
and dysfunctional knobs) removed SD_PERFER_SIBLING on CPU domain
On numa machine, that causes load_balance didn't perfer LCPU in same
physical CPU package.
It causes some regression on our numa machines from core2 to NHM and SNB.
Recover this domain flag can recover the performance drop.
This recovery doesn't has any bad impact on my all benchmarks specjbb,
kbuild, fio, hackbench .. etc, on all my machines.
Since it is a recovery, I assume it also has no bad impact for other
Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>
include/linux/topology.h | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/include/linux/topology.h b/include/linux/topology.h
index e91cd43..fec12d6 100644
@@ -164,6 +164,7 @@ int arch_update_cpu_topology(void);
| 0*SD_SHARE_CPUPOWER \
| 0*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
+ | 1*SD_PREFER_SIBLING \
.last_balance = jiffies, \
.balance_interval = 1, \
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