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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-07-09 15:15:43 +0200
committerIngo Molnar <mingo@elte.hu>2010-07-17 12:05:14 +0200
commitbbc8cb5baead9607309583b20873ab0cc8d89eaf (patch)
tree425cfb2772ef50c1858a7d833408ad1bcc423f51
parentsched: Update rq->clock for nohz balanced cpus (diff)
downloadlinux-bbc8cb5baead9607309583b20873ab0cc8d89eaf.tar.xz
linux-bbc8cb5baead9607309583b20873ab0cc8d89eaf.zip
sched: Reduce update_group_power() calls
Currently we update cpu_power() too often, update_group_power() only updates the local group's cpu_power but it gets called for all groups. Furthermore, CPU_NEWLY_IDLE invocations will result in all cpus calling it, even though a slow update of cpu_power is sufficient. Therefore move the update under 'idle != CPU_NEWLY_IDLE && local_group' to reduce superfluous invocations. Reported-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> LKML-Reference: <1278612989.1900.176.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/sched_fair.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index e44a591531a1..c9ac09760953 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -2425,14 +2425,14 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
* domains. In the newly idle case, we will allow all the cpu's
* to do the newly idle load balance.
*/
- if (idle != CPU_NEWLY_IDLE && local_group &&
- balance_cpu != this_cpu) {
- *balance = 0;
- return;
+ if (idle != CPU_NEWLY_IDLE && local_group) {
+ if (balance_cpu != this_cpu) {
+ *balance = 0;
+ return;
+ }
+ update_group_power(sd, this_cpu);
}
- update_group_power(sd, this_cpu);
-
/* Adjust by relative CPU power of the group */
sgs->avg_load = (sgs->group_load * SCHED_LOAD_SCALE) / group->cpu_power;