linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Aaron Tomlin <atomlin@redhat.com>
To: Christoph Lameter <cl@gentwo.de>
Cc: frederic@kernel.org, mtosatti@redhat.com, tglx@linutronix.de,
	mingo@kernel.org, peterz@infradead.org, pauld@redhat.com,
	neelx@redhat.com, oleksandr@natalenko.name,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC PATCH v3] tick/sched: Ensure quiet_vmstat() is called when the idle tick was stopped too
Date: Mon, 25 Apr 2022 12:39:09 +0100	[thread overview]
Message-ID: <20220425113909.u3smtztp66svlw4o@ava.usersys.com> (raw)
In-Reply-To: <alpine.DEB.2.22.394.2204250919400.2367@gentwo.de>

On Mon 2022-04-25 09:23 +0200, Christoph Lameter wrote:
> On Fri, 22 Apr 2022, Aaron Tomlin wrote:
> 
> > A customer provided some evidence which indicates that the idle tick was
> > stopped; albeit, CPU-specific vmstat counters still remained populated.
> > Thus one can only assume quiet_vmstat() was not invoked on return to the
> > idle loop.
> 
> Could we *always* fold the vmstat counters when entering idle mode? That
> would make the logic less complicated. There is nothing else to do since
> we are entering an idle state and if there are any counter deltas then we
> have the time to process them. This may also decrease the time that
> deltas exist significantly and an idle system will have accurate vmstat
> counters.

Hi Christoph,

Thank you for your feedback.

Yes, in the context of nohz, this patch should ensure it, if required, when
the idle tick is to be stopped.


Kind regards,

-- 
Aaron Tomlin



  reply	other threads:[~2022-04-25 11:39 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-22 19:36 Aaron Tomlin
2022-04-25  7:23 ` Christoph Lameter
2022-04-25 11:39   ` Aaron Tomlin [this message]
2022-04-25 12:09     ` Christoph Lameter
2022-04-25 13:27       ` Peter Zijlstra
2022-04-25 14:06         ` Christoph Lameter
2022-04-25 14:51           ` Aaron Tomlin
2022-04-25 14:57           ` Marcelo Tosatti
2022-04-25 14:17         ` Aaron Tomlin
2022-04-25 19:21           ` Marcelo Tosatti
2022-04-27 11:50             ` Aaron Tomlin
2022-04-27 14:40               ` Thomas Gleixner
2022-04-27 14:49                 ` Aaron Tomlin
2022-04-28 18:10 ` Marcelo Tosatti
2022-05-04  9:32   ` Aaron Tomlin

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=20220425113909.u3smtztp66svlw4o@ava.usersys.com \
    --to=atomlin@redhat.com \
    --cc=cl@gentwo.de \
    --cc=frederic@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mingo@kernel.org \
    --cc=mtosatti@redhat.com \
    --cc=neelx@redhat.com \
    --cc=oleksandr@natalenko.name \
    --cc=pauld@redhat.com \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    /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