From: Tejun Heo <tj@kernel.org>
To: Joe Lawrence <joe.lawrence@stratus.com>
Cc: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com,
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 15:47:48 -0400 [thread overview]
Message-ID: <20141005194748.GG8549@htj.dyndns.org> (raw)
In-Reply-To: <20141005192119.GE8549@htj.dyndns.org>
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>
Thanks.
--
tejun
next prev parent reply other threads:[~2014-10-05 19:47 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 [this message]
2014-10-06 4:21 ` Paul E. McKenney
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
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