All of lore.kernel.org
 help / color / mirror / Atom feed
From: Vincent Guittot <vincent.guittot@linaro.org>
To: Mike Galbraith <efault@gmx.de>
Cc: Mel Gorman <mgorman@techsingularity.net>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Valentin Schneider <valentin.schneider@arm.com>,
	Aubrey Li <aubrey.li@linux.intel.com>,
	Barry Song <song.bao.hua@hisilicon.com>,
	Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] sched/fair: Scale wakeup granularity relative to nr_running
Date: Thu, 23 Sep 2021 14:41:06 +0200	[thread overview]
Message-ID: <CAKfTPtDHYtskM7wR0w=fDry+6JJae2_q8Lw7ETcW_gBJ+n4NBA@mail.gmail.com> (raw)
In-Reply-To: <50400427070018eff83b0782d2e26c0cc9ff4521.camel@gmx.de>

On Thu, 23 Sept 2021 at 11:22, Mike Galbraith <efault@gmx.de> wrote:
>
> On Thu, 2021-09-23 at 10:40 +0200, Vincent Guittot wrote:
> >
> > a 100us value should even be enough to fix Mel's problem without
> > impacting common wakeup preemption cases.
>
> It'd be nice if it turn out to be something that simple, but color me
> skeptical.  I've tried various preemption throttling schemes, and while

Let's see what the results will show. I tend to agree that this will
not be enough to cover all use cases and I don't see any other way to
cover all cases than getting some inputs from the threads about their
latency fairness which bring us back to some kind of latency niceness
value

> it was trivial to get promising results, my scheme always managed to
> harm something.  Everything I ever tried, I ended up tossing.
>
>         -Mike

  reply	other threads:[~2021-09-23 12:41 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-20 14:26 [PATCH 0/2] Scale wakeup granularity relative to nr_running Mel Gorman
2021-09-20 14:26 ` [PATCH 1/2] sched/fair: Remove redundant lookup of rq in check_preempt_wakeup Mel Gorman
2021-09-21  7:21   ` Vincent Guittot
2021-09-21  7:53     ` Mel Gorman
2021-09-21  8:12       ` Vincent Guittot
2021-09-21  8:21       ` Peter Zijlstra
2021-09-21 10:03         ` Mel Gorman
2021-09-20 14:26 ` [PATCH 2/2] sched/fair: Scale wakeup granularity relative to nr_running Mel Gorman
2021-09-21  3:52   ` Mike Galbraith
2021-09-21  5:50     ` Mike Galbraith
2021-09-21  7:04     ` Mike Galbraith
2021-09-21 10:36     ` Mel Gorman
2021-09-21 12:32       ` Mike Galbraith
2021-09-21 14:03         ` Mel Gorman
2021-10-05  9:24         ` Peter Zijlstra
2021-09-22  5:22       ` Mike Galbraith
2021-09-22 13:20         ` Mel Gorman
2021-09-22 14:04           ` Mike Galbraith
2021-09-22 14:15           ` Vincent Guittot
2021-09-22 15:04             ` Mel Gorman
2021-09-22 16:00               ` Vincent Guittot
2021-09-22 17:38                 ` Mel Gorman
2021-09-22 18:22                   ` Vincent Guittot
2021-09-22 18:57                     ` Mel Gorman
2021-09-23  1:47                     ` Mike Galbraith
2021-09-23  8:40                       ` Vincent Guittot
2021-09-23  9:21                         ` Mike Galbraith
2021-09-23 12:41                           ` Vincent Guittot [this message]
2021-09-23 13:14                             ` Mike Galbraith
2021-09-27 11:17                             ` Mel Gorman
2021-09-27 14:17                               ` Mike Galbraith
2021-10-04  8:05                                 ` Mel Gorman
2021-10-04 16:37                                   ` Vincent Guittot
2021-10-05  7:41                                     ` Mel Gorman
2021-09-27 14:19                               ` Vincent Guittot
2021-09-27 15:02                                 ` Mel Gorman
2021-09-23 12:24                         ` Phil Auld
2021-10-05 10:36                           ` Peter Zijlstra
2021-10-05 14:12                             ` Phil Auld
2021-10-05 14:32                               ` Peter Zijlstra
2021-10-05 10:28                     ` Peter Zijlstra
2021-10-05 10:23                   ` Peter Zijlstra
2021-10-05  9:41               ` Peter Zijlstra
2021-09-22 15:05             ` Vincent Guittot
2021-10-05  9:32           ` Peter Zijlstra
2021-10-03  3:07         ` wakeup_affine_weight() is b0rked - was " Mike Galbraith
2021-10-03  7:34           ` Barry Song
2021-10-03 14:52             ` Mike Galbraith
2021-10-03 21:06               ` Barry Song
2021-10-04  1:49                 ` Mike Galbraith
2021-10-04  4:34             ` Mike Galbraith
2021-10-04  9:06               ` Mike Galbraith
2021-10-05  7:47                 ` Mel Gorman
2021-10-05  8:42                   ` Mike Galbraith
2021-10-05  9:31                     ` Mel Gorman
2021-10-06  6:46                       ` Mike Galbraith
2021-10-08  5:06                       ` Mike Galbraith
2021-09-21  8:03   ` Vincent Guittot
2021-09-21 10:45     ` Mel Gorman

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='CAKfTPtDHYtskM7wR0w=fDry+6JJae2_q8Lw7ETcW_gBJ+n4NBA@mail.gmail.com' \
    --to=vincent.guittot@linaro.org \
    --cc=aubrey.li@linux.intel.com \
    --cc=efault@gmx.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mgorman@techsingularity.net \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=song.bao.hua@hisilicon.com \
    --cc=srikar@linux.vnet.ibm.com \
    --cc=valentin.schneider@arm.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.