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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2008-09-20 23:38:02 +0200
committerIngo Molnar <mingo@elte.hu>2008-09-22 16:28:32 +0200
commit15afe09bf496ae10c989e1a375a6b5da7bd3e16e (patch)
tree4565659d1084e357eea42e6321a4d304ac950faa /kernel/sched_features.h
parent09b22a2f678ae733801b888c44756d0abd686b8a (diff)
downloadlinux-15afe09bf496ae10c989e1a375a6b5da7bd3e16e.tar.bz2
sched: wakeup preempt when small overlap
Lin Ming reported a 10% OLTP regression against 2.6.27-rc4. The difference seems to come from different preemption agressiveness, which affects the cache footprint of the workload and its effective cache trashing. Aggresively preempt a task if its avg overlap is very small, this should avoid the task going to sleep and find it still running when we schedule back to it - saving a wakeup. Reported-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_features.h')
-rw-r--r--kernel/sched_features.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index 9353ca78154e..bf027a7accf8 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -11,3 +11,4 @@ SCHED_FEAT(ASYM_GRAN, 1)
SCHED_FEAT(LB_BIAS, 1)
SCHED_FEAT(LB_WAKEUP_UPDATE, 1)
SCHED_FEAT(ASYM_EFF_LOAD, 1)
+SCHED_FEAT(WAKEUP_OVERLAP, 1)