sched: Only queue remote wakeups when crossing cache boundaries
authorPeter Zijlstra <a.p.zijlstra@chello.nl>
Wed, 7 Dec 2011 14:07:31 +0000 (15:07 +0100)
committerIngo Molnar <mingo@elte.hu>
Wed, 21 Dec 2011 09:34:44 +0000 (10:34 +0100)
commit518cd62341786aa4e3839810832af2fbc0de1ea4
treebd28f7fce47887e9c5d33bd772c8380255ef3065
parent612ef28a045efadb3a98d4492ead7806a146485d
sched: Only queue remote wakeups when crossing cache boundaries

Mike reported a 13% drop in netperf TCP_RR performance due to the
new remote wakeup code. Suresh too noticed some performance issues
with it.

Reducing the IPIs to only cross cache domains solves the observed
performance issues.

Reported-by: Suresh Siddha <suresh.b.siddha@intel.com>
Reported-by: Mike Galbraith <efault@gmx.de>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Dave Kleikamp <dave.kleikamp@oracle.com>
Link: http://lkml.kernel.org/r/1323338531.17673.7.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/sched/core.c
kernel/sched/fair.c
kernel/sched/sched.h