Messages in this thread Patch in this message | | | From | Viresh Kumar <> | Subject | [PATCH 2/2] sched/fair: Avoid calling sync_entity_load_avg() unnecessarily | Date | Thu, 26 Apr 2018 16:00:51 +0530 |
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Call sync_entity_load_avg() directly from find_idlest_cpu() instead of select_task_rq_fair(), as that's where we need to use task's utilization value. And call sync_entity_load_avg() only after making sure sched domain spans over one of the allowed CPUs for the task.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- kernel/sched/fair.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 84fc74ddbd4b..5b1b4f91f132 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6199,6 +6199,13 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p if (!cpumask_intersects(sched_domain_span(sd), &p->cpus_allowed)) return prev_cpu; + /* + * We need task's util for capacity_spare_wake, sync it up to prev_cpu's + * last_update_time. + */ + if (!(sd_flag & SD_BALANCE_FORK)) + sync_entity_load_avg(&p->se); + while (sd) { struct sched_group *group; struct sched_domain *tmp; @@ -6651,15 +6658,6 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f if (unlikely(sd)) { /* Slow path */ - - /* - * We're going to need the task's util for capacity_spare_wake - * in find_idlest_group. Sync it up to prev_cpu's - * last_update_time. - */ - if (!(sd_flag & SD_BALANCE_FORK)) - sync_entity_load_avg(&p->se); - new_cpu = find_idlest_cpu(sd, p, cpu, prev_cpu, sd_flag); } else if (sd_flag & SD_BALANCE_WAKE) { /* XXX always ? */ /* Fast path */ -- 2.15.0.194.g9af6a3dea062
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