linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Vincent Guittot <vincent.guittot@linaro.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Tejun Heo <tj@kernel.org>, Josef Bacik <josef@toxicpanda.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Mike Galbraith <efault@gmx.de>, Paul Turner <pjt@google.com>,
	Chris Mason <clm@fb.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Morten Rasmussen <morten.rasmussen@arm.com>,
	Ben Segall <bsegall@google.com>, Yuyang Du <yuyang.du@intel.com>
Subject: Re: [PATCH -v2 12/18] sched/fair: Rewrite PELT migration propagation
Date: Tue, 31 Oct 2017 17:38:41 +0100	[thread overview]
Message-ID: <CAKfTPtBE_MxhuSsb=b-_jEeFybk9pfZ3HPH+AziQxkDGprKC=g@mail.gmail.com> (raw)
In-Reply-To: <20171031150108.mxihmewrugufwulq@hirez.programming.kicks-ass.net>

On 31 October 2017 at 16:01, Peter Zijlstra <peterz@infradead.org> wrote:
> On Tue, Oct 31, 2017 at 12:14:11PM +0100, Vincent Guittot wrote:
>
>> > +       if (runnable_sum >= 0) {
>> > +               /*
>> > +                * Add runnable; clip at LOAD_AVG_MAX. Reflects that until
>> > +                * the CPU is saturated running == runnable.
>> > +                */
>> > +               runnable_sum += se->avg.load_sum;
>> > +               runnable_sum = min(runnable_sum, (long)LOAD_AVG_MAX);
>> > +       } else {
>> > +               /*
>> > +                * Estimate the departing task's runnable by assuming all tasks
>> > +                * are equally runnable.
>> > +                *
>> > +                * XXX: doesn't deal with multiple departures?
>>
>> Why this would not deal with multiple departures ?
>> we are using gcfs_rq->avg.load_sum that reflects the new state of the
>> gcfs_rq to evaluate the runnable_sum
>
> Ah, I figured the load_sum thing below reflected one average task worth
> of runnable.
>
>
>> > +       /* runnable_sum can't be lower than running_sum */
>> > +       running_sum = se->avg.util_sum >> SCHED_CAPACITY_SHIFT; /* XXX ? */
>>
>> running_sum is scaled by cpu's capacity but not load_sum
>>
>> I have made the shortcut of using SCHED_CAPACITY_SHIFT for capacity
>> but we might better use arch_scale_cpu_capacity(NULL, cpu) instead
>
> Ah, right. We should improve the comments thereabouts, I got totally
> lost trying to track that yesterday.
>
> Also; we should look at doing that invariant patch you're still sitting
> on.

Yes. I have to rebase and test lastest changes i did

  reply	other threads:[~2017-10-31 16:39 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-01 13:20 [PATCH -v2 00/18] sched/fair: A bit of a cgroup/PELT overhaul Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 01/18] sched/fair: Clean up calc_cfs_shares() Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 02/18] sched/fair: Add comment to calc_cfs_shares() Peter Zijlstra
2017-09-28 10:03   ` Morten Rasmussen
2017-09-29 11:35     ` Peter Zijlstra
2017-09-29 13:03       ` Morten Rasmussen
2017-09-01 13:21 ` [PATCH -v2 03/18] sched/fair: Cure calc_cfs_shares() vs reweight_entity() Peter Zijlstra
2017-09-29  9:04   ` Morten Rasmussen
2017-09-29 11:38     ` Peter Zijlstra
2017-09-29 13:00       ` Morten Rasmussen
2017-09-01 13:21 ` [PATCH -v2 04/18] sched/fair: Remove se->load.weight from se->avg.load_sum Peter Zijlstra
2017-09-29 15:26   ` Morten Rasmussen
2017-09-29 16:39     ` Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 05/18] sched/fair: Change update_load_avg() arguments Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 06/18] sched/fair: Move enqueue migrate handling Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 07/18] sched/fair: Rename {en,de}queue_entity_load_avg() Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 08/18] sched/fair: Introduce {en,de}queue_load_avg() Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 09/18] sched/fair: More accurate reweight_entity() Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 10/18] sched/fair: Use reweight_entity() for set_user_nice() Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 11/18] sched/fair: Rewrite cfs_rq->removed_*avg Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 12/18] sched/fair: Rewrite PELT migration propagation Peter Zijlstra
2017-10-09  8:08   ` Morten Rasmussen
2017-10-09  9:45     ` Peter Zijlstra
2017-10-18 12:45       ` Morten Rasmussen
2017-10-30 13:35         ` Peter Zijlstra
2017-10-09 15:03   ` Vincent Guittot
2017-10-09 15:29     ` Vincent Guittot
2017-10-10  7:29       ` Peter Zijlstra
2017-10-10  7:44         ` Vincent Guittot
2017-10-13 15:22           ` Vincent Guittot
2017-10-13 20:41             ` Peter Zijlstra
2017-10-15 12:01               ` Vincent Guittot
2017-10-16 13:55               ` Vincent Guittot
2017-10-19 15:04                 ` Vincent Guittot
2017-10-30 17:20                   ` Peter Zijlstra
2017-10-31 11:14                     ` Vincent Guittot
2017-10-31 15:01                       ` Peter Zijlstra
2017-10-31 16:38                         ` Vincent Guittot [this message]
2017-11-16 14:09                         ` [PATCH v3] sched: Update runnable propagation rule Vincent Guittot
2017-11-16 14:21                           ` [PATCH v4] " Vincent Guittot
2017-12-06 11:40                             ` Peter Zijlstra
2017-12-06 17:10                               ` Ingo Molnar
2017-12-06 20:29                             ` [tip:sched/core] sched/fair: Update and fix the " tip-bot for Vincent Guittot
2017-09-01 13:21 ` [PATCH -v2 13/18] sched/fair: Propagate an effective runnable_load_avg Peter Zijlstra
2017-10-02 17:46   ` Dietmar Eggemann
2017-10-03  8:50     ` Peter Zijlstra
2017-10-03  9:29       ` Dietmar Eggemann
2017-10-03 12:26   ` Dietmar Eggemann
2017-09-01 13:21 ` [PATCH -v2 14/18] sched/fair: Synchonous PELT detach on load-balance migrate Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 15/18] sched/fair: Align PELT windows between cfs_rq and its se Peter Zijlstra
2017-10-04 19:27   ` Dietmar Eggemann
2017-10-06 13:02     ` Peter Zijlstra
2017-10-09 12:15       ` Dietmar Eggemann
2017-10-09 12:19         ` Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 16/18] sched/fair: More accurate async detach Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 17/18] sched/fair: Calculate runnable_weight slightly differently Peter Zijlstra
2017-09-01 13:21 ` [PATCH -v2 18/18] sched/fair: Update calc_group_*() comments Peter Zijlstra

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='CAKfTPtBE_MxhuSsb=b-_jEeFybk9pfZ3HPH+AziQxkDGprKC=g@mail.gmail.com' \
    --to=vincent.guittot@linaro.org \
    --cc=bsegall@google.com \
    --cc=clm@fb.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=efault@gmx.de \
    --cc=josef@toxicpanda.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=morten.rasmussen@arm.com \
    --cc=peterz@infradead.org \
    --cc=pjt@google.com \
    --cc=tj@kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=yuyang.du@intel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).