Commit 6956dc56 authored by Alex Shi's avatar Alex Shi Committed by Ingo Molnar

sched/numa: Add SD_PERFER_SIBLING to CPU domain

Commit 8e7fbcbc ("sched: Remove stale power aware scheduling remnants
and dysfunctional knobs") removed SD_PERFER_SIBLING from the CPU domain.

On NUMA machines this causes that load_balance() doesn't perfer LCPU in
 same physical CPU package.

It causes some actual performance regressions on our NUMA machines from
Core2 to NHM and SNB.

Adding this domain flag again recovers the performance drop.

This change doesn't have any bad impact on any of my benchmarks:
 specjbb, kbuild, fio, hackbench .. etc, on all my machines.
Signed-off-by: default avatarAlex Shi <alex.shi@intel.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1342765190-21540-1-git-send-email-alex.shi@intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 8323f26c
......@@ -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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