From: Tejun Heo <tj@kernel.org>
To: Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Mike Galbraith <efault@gmx.de>, Paul Turner <pjt@google.com>,
Chris Mason <clm@fb.com>,
kernel-team@fb.com
Subject: [PATCH 3/2] sched/fair: Skip __update_load_avg() on cfs_rq sched_entities
Date: Mon, 24 Apr 2017 14:35:28 -0700 [thread overview]
Message-ID: <20170424213528.GB23619@wtj.duckdns.org> (raw)
In-Reply-To: <20170424201344.GA14169@wtj.duckdns.org>
Now that a cfs_rq sched_entity's load_avg always gets propagated from
the associated cfs_rq, there's no point in calling __update_load_avg()
on it. The two mechanisms compete with each other and we'd be always
using a value close to the propagated one anyway.
Skip __update_load_avg() for cfs_rq sched_entities. Also, relocate
propagate_entity_load_avg() to signify that propagation is the
counterpart to __update_load_avg() for cfs_rq sched_entities. This
puts the propagation before update_cfs_rq_load_avg() which shouldn't
disturb anything.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Turner <pjt@google.com>
---
Hello,
A follow-up patch. This removes __update_load_avg() on cfs_rq se's as
the value is now constantly kept in sync from cfs_rq. The patch
doesn't cause any noticable changes in tets.
Thanks.
kernel/sched/fair.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3293,20 +3293,22 @@ static inline void update_load_avg(struc
u64 now = cfs_rq_clock_task(cfs_rq);
struct rq *rq = rq_of(cfs_rq);
int cpu = cpu_of(rq);
- int decayed;
+ int decayed = 0;
/*
* Track task load average for carrying it to new CPU after migrated, and
* track group sched_entity load average for task_h_load calc in migration
*/
- if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD)) {
- __update_load_avg(now, cpu, &se->avg,
- se->on_rq * scale_load_down(se->load.weight),
- cfs_rq->curr == se, NULL);
+ if (entity_is_task(se)) {
+ if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD))
+ __update_load_avg(now, cpu, &se->avg,
+ se->on_rq * scale_load_down(se->load.weight),
+ cfs_rq->curr == se, NULL);
+ } else {
+ decayed |= propagate_entity_load_avg(se);
}
- decayed = update_cfs_rq_load_avg(now, cfs_rq, true);
- decayed |= propagate_entity_load_avg(se);
+ decayed |= update_cfs_rq_load_avg(now, cfs_rq, true);
if (decayed && (flags & UPDATE_TG))
update_tg_load_avg(cfs_rq, 0);
next prev parent reply other threads:[~2017-04-24 21:35 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-24 20:13 [RFC PATCHSET] sched/fair: fix load balancer behavior when cgroup is in use Tejun Heo
2017-04-24 20:14 ` [PATCH 1/2] sched/fair: Fix how load gets propagated from cfs_rq to its sched_entity Tejun Heo
2017-04-24 21:33 ` [PATCH v2 " Tejun Heo
2017-05-03 18:00 ` Peter Zijlstra
2017-05-03 21:45 ` Tejun Heo
2017-05-04 5:51 ` Peter Zijlstra
2017-05-04 6:21 ` Peter Zijlstra
2017-05-04 9:49 ` Dietmar Eggemann
2017-05-04 10:57 ` Peter Zijlstra
2017-05-04 17:39 ` Tejun Heo
2017-05-05 10:36 ` Dietmar Eggemann
2017-05-04 10:26 ` Vincent Guittot
2017-04-25 8:35 ` [PATCH " Vincent Guittot
2017-04-25 18:12 ` Tejun Heo
2017-04-26 16:51 ` Vincent Guittot
2017-04-26 22:40 ` Tejun Heo
2017-04-27 7:00 ` Vincent Guittot
2017-05-01 14:17 ` Peter Zijlstra
2017-05-01 14:52 ` Peter Zijlstra
2017-05-01 21:56 ` Tejun Heo
2017-05-02 8:19 ` Peter Zijlstra
2017-05-02 8:30 ` Peter Zijlstra
2017-05-02 20:00 ` Tejun Heo
2017-05-03 9:10 ` Peter Zijlstra
2017-04-26 16:14 ` Vincent Guittot
2017-04-26 22:27 ` Tejun Heo
2017-04-27 8:59 ` Vincent Guittot
2017-04-28 17:46 ` Tejun Heo
2017-05-02 7:20 ` Vincent Guittot
2017-04-24 20:14 ` [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo
2017-04-25 8:46 ` Vincent Guittot
2017-04-25 9:05 ` Vincent Guittot
2017-04-25 12:59 ` Vincent Guittot
2017-04-25 18:49 ` Tejun Heo
2017-04-25 20:49 ` Tejun Heo
2017-04-25 21:15 ` Chris Mason
2017-04-25 21:08 ` Tejun Heo
2017-04-26 10:21 ` Vincent Guittot
2017-04-27 0:30 ` Tejun Heo
2017-04-27 8:28 ` Vincent Guittot
2017-04-28 16:14 ` Tejun Heo
2017-05-02 6:56 ` Vincent Guittot
2017-05-02 20:56 ` Tejun Heo
2017-05-03 7:25 ` Vincent Guittot
2017-05-03 7:54 ` Vincent Guittot
2017-04-26 18:12 ` Vincent Guittot
2017-04-26 22:52 ` Tejun Heo
2017-04-27 8:29 ` Vincent Guittot
2017-04-28 20:33 ` Tejun Heo
2017-04-28 20:38 ` Tejun Heo
2017-05-01 15:56 ` Peter Zijlstra
2017-05-02 22:01 ` Tejun Heo
2017-05-02 7:18 ` Vincent Guittot
2017-05-02 13:26 ` Vincent Guittot
2017-05-02 22:37 ` Tejun Heo
2017-05-02 21:50 ` Tejun Heo
2017-05-03 7:34 ` Vincent Guittot
2017-05-03 9:37 ` Peter Zijlstra
2017-05-03 10:37 ` Vincent Guittot
2017-05-03 13:09 ` Peter Zijlstra
2017-05-03 21:49 ` Tejun Heo
2017-05-04 8:19 ` Vincent Guittot
2017-05-04 17:43 ` Tejun Heo
2017-05-04 19:02 ` Vincent Guittot
2017-05-04 19:04 ` Tejun Heo
2017-04-24 21:35 ` Tejun Heo [this message]
2017-04-24 21:48 ` [PATCH 3/2] sched/fair: Skip __update_load_avg() on cfs_rq sched_entities Peter Zijlstra
2017-04-24 22:54 ` Tejun Heo
2017-04-25 21:09 ` Tejun Heo
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