From: Valentin Schneider <valentin.schneider@arm.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: 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>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] sched/fair: improve spreading of utilization
Date: Fri, 13 Mar 2020 17:34:09 +0000 [thread overview]
Message-ID: <jhjzhcknoq6.mognet@arm.com> (raw)
In-Reply-To: <CAKfTPtCopLDoUsC+Mt6k99Hdn52pcKkrNYQsYNRW5LdgyMg4Nw@mail.gmail.com>
On Fri, Mar 13 2020, Vincent Guittot wrote:
>> My point is that if we prevent this for migrate_util, it would make
>> sense to prevent it for migrate_task, but it's not straightforward since
>
> hmm but we don't want to prevent this active balance for migrate_task
> because of cases like the one you mentioned above.
>
> we might consider to finally select a CPU with only 1 running task
> with migrate_util if there is no other CPU with more than 1 task. But
> this would complexify the code and I don't think it's possible because
> migrate_util is used to pull some utilizations from an overloaded
> group which must have a CPU with a waiting task to be overloaded.
>
OK, so what we may want in the future is a tighter link between
find_busiest_queue() and voluntary_active_balance(). I don't see a neat
way of doing this right now, I'll ponder over it.
Thanks for keeping up with my rambling.
next prev parent reply other threads:[~2020-03-13 17:34 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-12 16:54 [PATCH] sched/fair: improve spreading of utilization Vincent Guittot
2020-03-13 10:26 ` Peter Zijlstra
2020-03-13 11:00 ` Valentin Schneider
2020-03-13 11:24 ` Vincent Guittot
2020-03-13 11:28 ` Valentin Schneider
2020-03-13 12:42 ` Valentin Schneider
2020-03-13 12:55 ` Vincent Guittot
2020-03-13 14:26 ` Vincent Guittot
2020-03-13 15:47 ` Valentin Schneider
2020-03-13 16:09 ` Vincent Guittot
2020-03-13 16:57 ` Valentin Schneider
2020-03-13 17:12 ` Vincent Guittot
2020-03-13 17:34 ` Valentin Schneider [this message]
2020-03-20 12:58 ` [tip: sched/core] sched/fair: Improve " tip-bot2 for Vincent Guittot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=jhjzhcknoq6.mognet@arm.com \
--to=valentin.schneider@arm.com \
--cc=bsegall@google.com \
--cc=dietmar.eggemann@arm.com \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@suse.de \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=vincent.guittot@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.