From: Odin Ugedal <odin@uged.al>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Odin Ugedal <odin@uged.al>, Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
"open list:CONTROL GROUP (CGROUP)" <cgroups@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/3] sched/fair: Correctly insert cfs_rq's to list on unthrottle
Date: Sat, 29 May 2021 11:33:32 +0200 [thread overview]
Message-ID: <CAFpoUr04ziEzvNBJx0xKSuuEnapGzyABwaM-FU3TUaCZkQ4WPw@mail.gmail.com> (raw)
In-Reply-To: <CAKfTPtA6AyL2f-KqHXecZrYKmZ9r9mT=Ks6BeNLjV9dfbSZJxQ@mail.gmail.com>
Hi,
> normally tg_load_avg_contrib should be null when cfs_rq_is_decayed()
Yeah, I think that is an ok assumption of how it _should_ work (given
the other patches in flight are merged).
> The reason of this list is to ensure that the load of all cfs_rq are
> periodically updated as it is then used to share the runtime between
> groups so we should keep to use the rule whenever possible.
Yeah, right.
> we probably need to keep (cfs_rq->nr_running >= 1) as we can have case
> where tg_load_avg_contrib is null but a task is enqueued
Yeah, there is probably a chance of enqueuing a task without any load,
and then a parent gets throttled.
So (cfs_rq->tg_load_avg_contrib || cfs_rq->nr_running) is probably the
way to go if we want to avoid
a new field. Will resend a patch with that instead.
In case the new field is the main issue with the original solution, we
could also change the on_list int to have three modes like; NO, YES,
THROTTLED/PAUSED, but that would require a bigger rewrite of the other
logic, so probably outside the scope of this patch.
Thanks
Odin
next prev parent reply other threads:[~2021-05-29 9:34 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-18 12:51 [PATCH 0/3] sched/fair: Fix load decay issues related to throttling Odin Ugedal
2021-05-18 12:52 ` [PATCH 1/3] sched/fair: Add tg_load_contrib cfs_rq decay checking Odin Ugedal
2021-05-25 9:58 ` Vincent Guittot
2021-05-25 10:33 ` Odin Ugedal
2021-05-25 14:30 ` Vincent Guittot
2021-05-26 10:50 ` Vincent Guittot
2021-05-27 7:50 ` Odin Ugedal
2021-05-27 9:35 ` Vincent Guittot
2021-05-27 9:45 ` Odin Ugedal
2021-05-27 10:49 ` Vincent Guittot
2021-05-27 11:04 ` Odin Ugedal
2021-05-27 12:37 ` Vincent Guittot
2021-05-27 12:37 ` Odin Ugedal
2021-05-27 12:39 ` Odin Ugedal
2021-05-27 12:49 ` Vincent Guittot
2021-05-18 12:52 ` [PATCH 2/3] sched/fair: Correctly insert cfs_rq's to list on unthrottle Odin Ugedal
2021-05-28 14:24 ` Vincent Guittot
2021-05-28 15:06 ` Odin Ugedal
2021-05-28 15:27 ` Vincent Guittot
2021-05-29 9:33 ` Odin Ugedal [this message]
2021-05-31 12:14 ` Vincent Guittot
2021-05-18 12:52 ` [PATCH 3/3] sched/fair: Fix ascii art by relpacing tabs Odin Ugedal
2021-05-27 13:27 ` Vincent Guittot
2021-06-01 14:04 ` [tip: sched/core] " tip-bot2 for Odin Ugedal
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