[tip:sched/core] sched: Reduce update_group_power() calls
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From: tip-bot for Peter Zijlstra on 17 Jul 2010 07:20 Commit-ID: bbc8cb5baead9607309583b20873ab0cc8d89eaf Gitweb: http://git.kernel.org/tip/bbc8cb5baead9607309583b20873ab0cc8d89eaf Author: Peter Zijlstra <a.p.zijlstra(a)chello.nl> AuthorDate: Fri, 9 Jul 2010 15:15:43 +0200 Committer: Ingo Molnar <mingo(a)elte.hu> CommitDate: Sat, 17 Jul 2010 12:05:14 +0200 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(a)google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra(a)chello.nl> Acked-by: Suresh Siddha <suresh.b.siddha(a)intel.com> LKML-Reference: <1278612989.1900.176.camel(a)laptop> Signed-off-by: Ingo Molnar <mingo(a)elte.hu> --- kernel/sched_fair.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index e44a591..c9ac097 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |