From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Josh Boyer <jwboyer@redhat.com>
Cc: linux-kernel@vger.kernel.org, kernel-team@fedoraproject.org
Subject: Re: RCU related performance regression in 3.3
Date: Wed, 4 Apr 2012 14:36:33 -0700 [thread overview]
Message-ID: <20120404213633.GI2302@linux.vnet.ibm.com> (raw)
In-Reply-To: <20120404152726.GB16299@zod.bos.redhat.com>
On Wed, Apr 04, 2012 at 11:27:27AM -0400, Josh Boyer wrote:
> Hi Paul,
>
> We've had a few reports of some boot slowdowns with the 3.3 rebase we
> did in Fedora 16. One of our users volunteered to bisect a vanilla
> kernel and wound up at "rcu: Permit dyntick-idle with callbacks pending
> (commit 7cb924990)". You can find more details in the bug [1], but it's
> been reported on both physical hardware and in virtual machines.
>
> Have you seen anything like this in your testing? Given the user used a
> vanilla 3.3 kernel, I'm wondering if there is a targetted fix that might
> be backported. If so, it would be good to get that headed to the 3.3.y
> stable tree.
>
> josh
>
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=806548
I will look into this. In the meantime, does setting
CONFIG_RCU_FAST_NO_HZ=n get rid of the slowdowns?
Thanx, Paul
next prev parent reply other threads:[~2012-04-04 21:36 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-04 15:27 RCU related performance regression in 3.3 Josh Boyer
2012-04-04 21:36 ` Paul E. McKenney [this message]
2012-04-05 12:37 ` Josh Boyer
2012-04-05 14:00 ` Paul E. McKenney
2012-04-05 14:15 ` Pascal CHAPPERON
2012-04-05 14:39 ` Paul E. McKenney
2012-04-06 9:18 ` Pascal Chapperon
2012-04-10 16:07 ` Paul E. McKenney
2012-04-11 15:06 ` Pascal
2012-04-12 18:04 ` Paul E. McKenney
2012-04-16 21:02 ` Paul E. McKenney
2012-04-18 9:37 ` Pascal Chapperon
2012-04-18 14:01 ` Paul E. McKenney
2012-04-18 15:00 ` Pascal Chapperon
2012-04-18 15:23 ` Paul E. McKenney
2012-04-20 14:45 ` Pascal Chapperon
-- strict thread matches above, loose matches on Subject: below --
2012-04-27 12:15 Pascal Chapperon
2012-04-28 3:42 ` Paul E. McKenney
2012-05-01 0:02 ` Paul E. McKenney
2012-05-01 8:55 ` Pascal Chapperon
2012-05-01 15:45 ` Paul E. McKenney
2012-05-04 14:42 ` Pascal Chapperon
2012-05-04 15:04 ` Paul E. McKenney
2012-05-04 21:41 ` Pascal Chapperon
2012-05-04 23:14 ` Paul E. McKenney
2012-05-10 8:40 ` Pascal Chapperon
2012-05-14 22:32 ` Paul E. McKenney
2012-05-18 11:01 ` Pascal Chapperon
2012-05-18 12:14 ` Paul E. McKenney
2012-05-18 14:48 ` Pascal Chapperon
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=20120404213633.GI2302@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=jwboyer@redhat.com \
--cc=kernel-team@fedoraproject.org \
--cc=linux-kernel@vger.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.