From: Aaron Tomlin <atomlin@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Lameter <cl@gentwo.de>,
frederic@kernel.org, mtosatti@redhat.com, tglx@linutronix.de,
mingo@kernel.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 15:17:17 +0100 [thread overview]
Message-ID: <20220425141717.vw2jfnn3zp6c5ib2@ava.usersys.com> (raw)
In-Reply-To: <20220425132700.GK2731@worktop.programming.kicks-ass.net>
On Mon 2022-04-25 15:27 +0200, Peter Zijlstra wrote:
> On Mon, Apr 25, 2022 at 02:09:06PM +0200, Christoph Lameter wrote:
> > On Mon, 25 Apr 2022, Aaron Tomlin wrote:
> >
> > > Yes, in the context of nohz, this patch should ensure it, if required, when
> > > the idle tick is to be stopped.
> >
> > What I said was that it is generally useful. Even in the non NOHZ case.
> >
> > Folding the vmstat diffs *always* when entering idle prevents unnecessary
> > wakeups and processing in the future and also provides more accurate
> > counters for the VM allowing better decision to be made on reclaim.
>
> I'm thinking you're going to find a ton of regressions if you try it
> though; some workloads go idle *very* shortly, doing all this accounting
> is going to be counter-productive.
Hi Peter, Christoph,
Indeed. Which was why I decided, initially, against the general-purpose
case/or approach. Personally, I would prefer to keep this somewhat
restrictive to nohz.
Kind regards,
--
Aaron Tomlin
next prev parent reply other threads:[~2022-04-25 14:17 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
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 [this message]
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
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