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| author | Ken Chen <kenchen@google.com> | 2008-12-07 18:47:37 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-08 13:52:44 +0100 |
| commit | 5436499e6098759c2340f8b906ea52f993dc4efb (patch) | |
| tree | 5af189c8d0d8bf5bc6261a427c371bd4d8ba7474 /kernel | |
| parent | 4d117c5c6b00254e51c61ff5b506ccaba21a5a03 (diff) | |
| download | lwn-5436499e6098759c2340f8b906ea52f993dc4efb.tar.gz lwn-5436499e6098759c2340f8b906ea52f993dc4efb.zip | |
sched: fix sd_parent_degenerate on non-numa smp machine
Impact: optimize the sched domains tree some more
The addition of SD_SERIALIZE flag added to SD_NODE_INIT prevented top level
dummy numa sched_domain to be properly degenerated on non-numa smp machine.
The reason is that in sd_parent_degenerate(), it found that the child and
parent does not have comon sched_domain flags due to SD_SERIALIZE. However,
for non-numa smp box, the top level is a dummy with a single sched_group.
Filter out SD_SERIALIZE if it is on non-numa machine to properly degenerate
top level node sched_domain. this will cut back some of the sd domain walk
in the load balancer code.
Signed-off-by: Ken Chen <kenchen@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 152828239ef0..74498c840f93 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6768,6 +6768,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) SD_BALANCE_EXEC | SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES); + if (nr_node_ids == 1) + pflags &= ~SD_SERIALIZE; } if (~cflags & pflags) return 0; |