linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Frederic Weisbecker <frederic@kernel.org>
To: Juri Lelli <juri.lelli@redhat.com>
Cc: fweisbec@gmail.com, tglx@linutronix.de, mingo@kernel.org,
	linux-rt-users@vger.kernel.org, peterz@infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] tick/sched: update full_nohz status after SCHED dep is cleared
Date: Mon, 29 Jun 2020 14:42:08 +0200	[thread overview]
Message-ID: <20200629124207.GA6088@lenoir> (raw)
In-Reply-To: <20200629123651.GA9670@localhost.localdomain>

On Mon, Jun 29, 2020 at 02:36:51PM +0200, Juri Lelli wrote:
> Hi,
> 
> On 16/06/20 22:46, Frederic Weisbecker wrote:
> > On Tue, Jun 16, 2020 at 08:57:57AM +0200, Juri Lelli wrote:
> > > Sure. Let me know if you find anything.
> > 
> > I managed to reproduce. With "threadirqs" and without
> > "tsc=reliable". I see tons of spurious TIMER softirqs.
> > Investigation begins! I'll let you know.
> 
> Gentle ping. Any new findings about this issue?

Yep, I'm working on a series to reduce timer softirqs. I'm almost
done, should post it soon.

I believe you guessed right:

* Timer tick raises timer softirq
* Ksoftirqd wakes up, restarts the tick
* Timer tick raises timer softirq
* ...

Thanks.

  reply	other threads:[~2020-06-29 21:35 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-20 14:04 [RFC PATCH] tick/sched: update full_nohz status after SCHED dep is cleared Juri Lelli
2020-05-20 16:24 ` Frederic Weisbecker
2020-05-20 16:49   ` Juri Lelli
2020-05-20 17:02     ` Frederic Weisbecker
2020-05-20 18:47       ` Juri Lelli
2020-05-21  0:44         ` Frederic Weisbecker
2020-05-21 17:00           ` Juri Lelli
2020-06-15 15:05             ` Juri Lelli
2020-06-15 21:07             ` Frederic Weisbecker
2020-06-16  6:57               ` Juri Lelli
2020-06-16 20:46                 ` Frederic Weisbecker
2020-06-29 12:36                   ` Juri Lelli
2020-06-29 12:42                     ` Frederic Weisbecker [this message]
2020-06-29 12:53                       ` Juri Lelli

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=20200629124207.GA6088@lenoir \
    --to=frederic@kernel.org \
    --cc=fweisbec@gmail.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rt-users@vger.kernel.org \
    --cc=mingo@kernel.org \
    --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;
as well as URLs for NNTP newsgroup(s).