All of lore.kernel.org
 help / color / mirror / Atom feed
From: Vincent Guittot <vincent.guittot@linaro.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: 王贇 <yun.wang@linux.alibaba.com>, "Ingo Molnar" <mingo@redhat.com>,
	"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>,
	"open list:SCHEDULER" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH] sched: fix the nonsense shares when load of cfs_rq is too, small
Date: Wed, 4 Mar 2020 12:55:21 +0100	[thread overview]
Message-ID: <CAKfTPtDrSzET+=G7rHvhDY3491CzGvp3ZqW0cqR8jhC1EvC2mQ@mail.gmail.com> (raw)
In-Reply-To: <20200304095209.GK2596@hirez.programming.kicks-ass.net>

On Wed, 4 Mar 2020 at 10:52, Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Wed, Mar 04, 2020 at 09:47:34AM +0100, Vincent Guittot wrote:
> > you will add +1 of nice prio for each device
> >
> > should we use instead
> > # define scale_load_down(w) ((w >> SCHED_FIXEDPOINT_SHIFT) ? (w >>
> > SCHED_FIXEDPOINT_SHIFT) : MIN_SHARES)
>
> That's '((w >> SHIFT) ?: MIN_SHARES)', but even that is not quite right.
>
> I think we want something like:
>
> #define scale_load_down(w) \
> ({ unsigned long ___w = (w); \
>    if (___w) \
>      ____w = max(MIN_SHARES, ___w >> SHIFT); \
>    ___w; })
>
> That is, we very much want to retain 0 I'm thinking.

yes, you're right

  reply	other threads:[~2020-03-04 11:55 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-03 14:17 [RFC PATCH] sched: fix the nonsense shares when load of cfs_rq is too, small 王贇
2020-03-03 19:52 ` Peter Zijlstra
2020-03-04  1:19   ` 王贇
2020-03-04  8:47     ` Vincent Guittot
2020-03-04  9:43       ` Vincent Guittot
2020-03-05  1:23         ` 王贇
2020-03-04  9:52       ` Peter Zijlstra
2020-03-04 11:55         ` Vincent Guittot [this message]
2020-03-05  1:08         ` 王贇
2020-03-04  8:45   ` Vincent Guittot
2020-03-04 18:47   ` bsegall
2020-03-05  1:14     ` 王贇
2020-03-05  7:53       ` Vincent Guittot
2020-03-06  4:23         ` 王贇
2020-03-06  8:04           ` Vincent Guittot
2020-03-06  9:34             ` 王贇
2020-03-06 19:17       ` bsegall
2020-03-09 11:15         ` Vincent Guittot
2020-03-10  3:42           ` 王贇
2020-03-10  7:57             ` Vincent Guittot
2020-03-10  8:15               ` 王贇

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='CAKfTPtDrSzET+=G7rHvhDY3491CzGvp3ZqW0cqR8jhC1EvC2mQ@mail.gmail.com' \
    --to=vincent.guittot@linaro.org \
    --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=yun.wang@linux.alibaba.com \
    /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.