All of lore.kernel.org
 help / color / mirror / Atom feed
From: Chris Metcalf <cmetcalf@mellanox.com>
To: Rik van Riel <riel@redhat.com>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Christoph Lameter <cl@linux.com>, Ingo Molnar <mingo@kernel.org>,
	Luiz Capitulino <lcapitulino@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] nohz_full: Make sched_should_stop_tick() more conservative
Date: Mon, 4 Apr 2016 20:27:30 -0400	[thread overview]
Message-ID: <57030672.8080405@mellanox.com> (raw)
In-Reply-To: <1459798571.6219.23.camel@redhat.com>

On 4/4/2016 3:36 PM, Rik van Riel wrote:
>>> On Fri, 2016-04-01 at 15:42 -0400, Chris Metcalf wrote:
>>>> On arm64, when calling enqueue_task_fair() from
>>>> migration_cpu_stop(),
>>>> we find the nr_running value updated by add_nr_running(), but the
>>>> cfs.nr_running value has not always yet been
>>>> updated.  Accordingly,
>>>> the sched_can_stop_tick() false returns true when we are
>>>> migrating a
>>>> second task onto a core.
>>>> Correct this by using rq->nr_running instead of rq-
>>>>> cfs.nr_running.
>>>> This should always be more conservative, and reverts the test to
>>>> the
>>>> form it had before commit 76d92ac305f2 ("sched: Migrate sched to
>>>> use
>>>> new tick dependency mask model").
>>>>
>>>>
> [...]
>
> Patch gets my:
>
> Acked-by: Rik van Riel <riel@redhat.com>

Thanks!  Whose tree should this go through: Frederic, PeterZ, Ingo?
Do any of you have any concerns with it?

-- 
Chris Metcalf, Mellanox Technologies
http://www.mellanox.com

      reply	other threads:[~2016-04-05  0:27 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-01 19:42 [PATCH] nohz_full: Make sched_should_stop_tick() more conservative Chris Metcalf
2016-04-04 19:12 ` Rik van Riel
2016-04-04 19:23   ` Peter Zijlstra
2016-04-18  2:00     ` Wanpeng Li
2016-04-21 14:42       ` Peter Zijlstra
2016-04-21 16:03         ` Peter Zijlstra
2016-04-25 21:30           ` Chris Metcalf
2016-04-28 10:24           ` [tip:sched/urgent] nohz/full, sched/rt: Fix missed tick-reenabling bug in sched_can_stop_tick() tip-bot for Peter Zijlstra
2016-04-28 13:30             ` Frederic Weisbecker
2016-04-04 19:31   ` [PATCH] nohz_full: Make sched_should_stop_tick() more conservative Chris Metcalf
2016-04-04 19:36     ` Rik van Riel
2016-04-05  0:27       ` Chris Metcalf [this message]

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=57030672.8080405@mellanox.com \
    --to=cmetcalf@mellanox.com \
    --cc=cl@linux.com \
    --cc=fweisbec@gmail.com \
    --cc=lcapitulino@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=riel@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=viresh.kumar@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.