Linux RCU subsystem development
 help / color / mirror / Atom feed
From: "Cheng-Jui Wang (王正睿)" <Cheng-Jui.Wang@mediatek.com>
To: "frederic@kernel.org" <frederic@kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"peterz@infradead.org" <peterz@infradead.org>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"qiang.zhang1211@gmail.com" <qiang.zhang1211@gmail.com>,
	"paulmck@kernel.org" <paulmck@kernel.org>,
	"neeraj.upadhyay@amd.com" <neeraj.upadhyay@amd.com>,
	"Bobule Chang (張弘義)" <bobule.chang@mediatek.com>,
	"boqun.feng@gmail.com" <boqun.feng@gmail.com>,
	"urezki@gmail.com" <urezki@gmail.com>,
	"joel@joelfernandes.org" <joel@joelfernandes.org>,
	"rcu@vger.kernel.org" <rcu@vger.kernel.org>
Subject: Re: [PATCH 2/3] rcu: Defer RCU kthreads wakeup when CPU is dying
Date: Mon, 12 Aug 2024 11:53:15 +0000	[thread overview]
Message-ID: <29781c9b46641e3cbcd9d3874cb18f90ea916193.camel@mediatek.com> (raw)
In-Reply-To: <ZrnuctZQS4DTSb0q@localhost.localdomain>

On Mon, 2024-08-12 at 13:13 +0200, Frederic Weisbecker wrote:
> 
> This means you are setting rcuo kthreads as real time
> tasks. I would be curious about your usecase.

I think it might simply be that CONFIG_RCU_BOOST=y was enabled. This
causes kthread_prio to be set to 1.

	static int kthread_prio = IS_ENABLED(CONFIG_RCU_BOOST) ? 1 : 0;

Then, when creating rcuog kthread, since kthread_prio is 1, it will
automatically set it to SCHED_FIFO.

	t = kthread_run(..., "rcuog/%d", ...);
	...
	if (kthread_prio)
		sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);

Thanks.

  reply	other threads:[~2024-08-12 11:53 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-18 23:19 [PATCH 0/3] timers & RCU: Fix TREE03 stalls Frederic Weisbecker
2023-12-18 23:19 ` [PATCH 1/3] hrtimer: Report offline hrtimer enqueue Frederic Weisbecker
2023-12-18 23:19 ` [PATCH 2/3] rcu: Defer RCU kthreads wakeup when CPU is dying Frederic Weisbecker
2023-12-19  3:38   ` Joel Fernandes
2023-12-19 11:56     ` Frederic Weisbecker
2023-12-20  3:01       ` Joel Fernandes
2023-12-20 15:50         ` Frederic Weisbecker
2023-12-21  0:57           ` Paul E. McKenney
2023-12-19 15:29   ` Paul E. McKenney
2023-12-19 15:47     ` Frederic Weisbecker
2023-12-20  8:24   ` Z qiang
2023-12-20 15:13     ` Frederic Weisbecker
2024-08-12  9:10       ` Cheng-Jui Wang (王正睿)
2024-08-12 11:13         ` Frederic Weisbecker
2024-08-12 11:53           ` Cheng-Jui Wang (王正睿) [this message]
2023-12-18 23:19 ` [PATCH 3/3] rcu/exp: Remove full barrier upon main thread wakeup Frederic Weisbecker
2023-12-19  1:40 ` [PATCH 0/3] timers & RCU: Fix TREE03 stalls Paul E. McKenney

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=29781c9b46641e3cbcd9d3874cb18f90ea916193.camel@mediatek.com \
    --to=cheng-jui.wang@mediatek.com \
    --cc=bobule.chang@mediatek.com \
    --cc=boqun.feng@gmail.com \
    --cc=frederic@kernel.org \
    --cc=joel@joelfernandes.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=neeraj.upadhyay@amd.com \
    --cc=paulmck@kernel.org \
    --cc=peterz@infradead.org \
    --cc=qiang.zhang1211@gmail.com \
    --cc=rcu@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=urezki@gmail.com \
    /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