From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Tejun Heo <tj@kernel.org>
Cc: Joe Lawrence <joe.lawrence@stratus.com>,
linux-kernel@vger.kernel.org, jiri@resnulli.us,
stable@vger.kernel.org
Subject: Re: [PATCH v2 1/2] workqueue: add quiescent state between work items
Date: Sun, 5 Oct 2014 21:21:58 -0700 [thread overview]
Message-ID: <20141006042158.GW5015@linux.vnet.ibm.com> (raw)
In-Reply-To: <20141005194748.GG8549@htj.dyndns.org>
On Sun, Oct 05, 2014 at 03:47:48PM -0400, Tejun Heo wrote:
> On Sun, Oct 05, 2014 at 03:21:19PM -0400, Tejun Heo wrote:
> > On Sun, Oct 05, 2014 at 01:24:21PM -0400, Joe Lawrence wrote:
> > > Similar to the stop_machine deadlock scenario on !PREEMPT kernels
> > > addressed in b22ce2785d97 "workqueue: cond_resched() after processing
> > > each work item", kworker threads requeueing back-to-back with zero jiffy
> > > delay can stall RCU. The cond_resched call introduced in that fix will
> > > yield only iff there are other higher priority tasks to run, so force a
> > > quiescent RCU state between work items.
> > >
> > > Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
> > > Link: https://lkml.kernel.org/r/20140926105227.01325697@jlaw-desktop.mno.stratus.com
> > > Link: https://lkml.kernel.org/r/20140929115445.40221d8e@jlaw-desktop.mno.stratus.com
> > > Fixes: b22ce2785d97 ("workqueue: cond_resched() after processing each work item")
> > > Cc: <stable@vger.kernel.org>
> >
> > Applied to wq/for-3.17-fixes. If 3.17 comes out before this gets
> > merged, I'll send it as for-3.18.
>
> Oops, the rcu calls aren't in mainline yet. I think it'd be best to
> route these through the RCU tree. Paul, can you please route these
> two patches?
>
> Acked-by: Tejun Heo <tj@kernel.org>
Will do!
I will try 3.17, failing that, 3.18.
Thanx, Paul
next prev parent reply other threads:[~2014-10-06 4:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1412529862-17954-1-git-send-email-joe.lawrence@stratus.com>
2014-10-05 17:24 ` [PATCH v2 1/2] workqueue: add quiescent state between work items Joe Lawrence
2014-10-05 19:21 ` Tejun Heo
2014-10-05 19:47 ` Tejun Heo
2014-10-06 4:21 ` Paul E. McKenney [this message]
2014-10-07 7:29 ` Jiri Pirko
2014-10-07 13:43 ` Paul E. McKenney
2014-10-07 17:45 ` Joe Lawrence
2014-10-08 3:24 ` Paul E. McKenney
2014-10-08 11:54 ` Jiri Pirko
2014-10-08 12:19 ` 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=20141006042158.GW5015@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=jiri@resnulli.us \
--cc=joe.lawrence@stratus.com \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@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).