From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, hpa@zytor.com,
paul.mckenney@linaro.org, rmk+kernel@arm.linux.org.uk,
weber@corscience.de, tglx@linutronix.de,
linux-tip-commits@vger.kernel.org
Subject: Re: [tip:core/urgent] rcu: avoid pointless blocked-task warnings
Date: Sat, 15 Jan 2011 16:15:16 -0800 [thread overview]
Message-ID: <20110116001516.GB2229@linux.vnet.ibm.com> (raw)
In-Reply-To: <20110115142857.GA8610@elte.hu>
On Sat, Jan 15, 2011 at 03:28:57PM +0100, Ingo Molnar wrote:
>
> * tip-bot for Paul E. McKenney <paul.mckenney@linaro.org> wrote:
>
> > Commit-ID: b24efdfdf679cf9b05947c531971905fc727dd40
> > Gitweb: http://git.kernel.org/tip/b24efdfdf679cf9b05947c531971905fc727dd40
> > Author: Paul E. McKenney <paul.mckenney@linaro.org>
> > AuthorDate: Wed, 12 Jan 2011 14:18:11 -0800
> > Committer: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> > CommitDate: Fri, 14 Jan 2011 04:58:08 -0800
> >
> > rcu: avoid pointless blocked-task warnings
> >
> > If the RCU callback-processing kthread has nothing to do, it parks in
> > a wait_event(). If RCU remains idle for more than two minutes, the
> > kernel complains about this. This commit changes from wait_event()
> > to wait_event_interruptible() to prevent the kernel from complaining
> > just because RCU is idle.
>
> Btw., a sidenote, it's not just about the blocked-tasks lockup detector warning,
> uninterruptible sleeps will also artificially inflate the load average of the box,
> +1.0 per such task. So it's definitely a bug to sleep for a very long time
> uninterruptible.
Good point, and I have made the corresponding change in the in-progress
TREE_PREEMPT_RCU variant of RCU priority boosting. Some thought will be
required when merging SRCU into the Tiny and Tree RCU implementations. ;-)
Thanx, Paul
prev parent reply other threads:[~2011-01-16 0:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <tip-b24efdfdf679cf9b05947c531971905fc727dd40@git.kernel.org>
2011-01-15 14:28 ` [tip:core/urgent] rcu: avoid pointless blocked-task warnings Ingo Molnar
2011-01-16 0:15 ` Paul E. McKenney [this message]
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=20110116001516.GB2229@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=mingo@redhat.com \
--cc=paul.mckenney@linaro.org \
--cc=rmk+kernel@arm.linux.org.uk \
--cc=tglx@linutronix.de \
--cc=weber@corscience.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