From: Leonardo Bras <leobras@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: Leonardo Bras <leobras@redhat.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
linux-kernel@vger.kernel.org, Junyao Zhao <junzhao@redhat.com>
Subject: Re: [PATCH v2 1/1] wq: Avoid using isolated cpus' timers on queue_delayed_work
Date: Mon, 29 Jan 2024 23:58:07 -0300 [thread overview]
Message-ID: <Zbhlv4EDS8qPmg_3@LeoBras> (raw)
In-Reply-To: <ZbhPWSWAZZo8gk-a@slm.duckdns.org>
On Mon, Jan 29, 2024 at 03:22:33PM -1000, Tejun Heo wrote:
> On Mon, Jan 29, 2024 at 10:00:46PM -0300, Leonardo Bras wrote:
> > When __queue_delayed_work() is called, it chooses a cpu for handling the
> > timer interrupt. As of today, it will pick either the cpu passed as
> > parameter or the last cpu used for this.
> >
> > This is not good if a system does use CPU isolation, because it can take
> > away some valuable cpu time to:
> > 1 - deal with the timer interrupt,
> > 2 - schedule-out the desired task,
> > 3 - queue work on a random workqueue, and
> > 4 - schedule the desired task back to the cpu.
> >
> > So to fix this, during __queue_delayed_work(), if cpu isolation is in
> > place, pick a random non-isolated cpu to handle the timer interrupt.
> >
> > As an optimization, if the current cpu is not isolated, use it instead
> > of looking for another candidate.
> >
> > Signed-off-by: Leonardo Bras <leobras@redhat.com>
>
> Applied to wq/for-6.9.
>
> Thanks.
>
> --
> tejun
>
Thank you!
Leo
next prev parent reply other threads:[~2024-01-30 2:58 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-30 1:00 [PATCH v2 1/1] wq: Avoid using isolated cpus' timers on queue_delayed_work Leonardo Bras
2024-01-30 1:22 ` Tejun Heo
2024-01-30 2:58 ` Leonardo Bras [this message]
2024-04-02 10:58 ` Oleg Nesterov
2024-04-03 19:12 ` Tejun Heo
2024-04-03 20:38 ` Oleg Nesterov
2024-04-05 14:04 ` Oleg Nesterov
2024-04-05 15:38 ` Tejun Heo
2024-04-05 22:03 ` Frederic Weisbecker
2024-04-05 21:52 ` Nohz_full on boot CPU is broken (was: Re: [PATCH v2 1/1] wq: Avoid using isolated cpus' timers on queue_delayed_work) Frederic Weisbecker
2024-04-07 13:09 ` Oleg Nesterov
2024-04-07 13:52 ` Oleg Nesterov
2024-04-09 12:05 ` Frederic Weisbecker
2024-04-09 12:04 ` Frederic Weisbecker
2024-04-09 13:07 ` Oleg Nesterov
2024-04-09 13:59 ` Frederic Weisbecker
2024-04-10 4:26 ` Nicholas Piggin
2024-04-10 13:55 ` Oleg Nesterov
2024-04-11 13:41 ` Oleg Nesterov
2024-04-11 14:39 ` [PATCH] sched/isolation: fix boot crash when the boot CPU is nohz_full Oleg Nesterov
2024-04-11 16:59 ` Oleg Nesterov
2024-04-13 14:17 ` [PATCH] sched/isolation: fix boot crash when maxcpus < first-housekeeping-cpu Oleg Nesterov
2024-04-18 14:54 ` Phil Auld
2024-04-18 15:40 ` Frederic Weisbecker
2024-04-24 20:05 ` [tip: sched/urgent] sched/isolation: Fix boot crash when maxcpus < first housekeeping CPU tip-bot2 for Oleg Nesterov
2024-04-28 8:13 ` Ingo Molnar
2024-04-28 13:16 ` Oleg Nesterov
2024-04-28 8:24 ` tip-bot2 for Oleg Nesterov
2024-04-15 21:37 ` [PATCH] sched/isolation: fix boot crash when the boot CPU is nohz_full Frederic Weisbecker
2024-04-18 14:50 ` Phil Auld
2024-04-22 18:50 ` Oleg Nesterov
2024-04-24 14:42 ` Phil Auld
2024-04-24 20:05 ` [tip: sched/urgent] sched/isolation: {revent " tip-bot2 for Oleg Nesterov
2024-04-24 20:41 ` Phil Auld
2024-04-28 8:14 ` Ingo Molnar
2024-04-29 11:50 ` Phil Auld
2024-04-28 8:24 ` [tip: sched/urgent] sched/isolation: Prevent " tip-bot2 for Oleg Nesterov
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=Zbhlv4EDS8qPmg_3@LeoBras \
--to=leobras@redhat.com \
--cc=jiangshanlai@gmail.com \
--cc=junzhao@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=tj@kernel.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 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).