From: Tejun Heo <tj@kernel.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: jiangshanlai@gmail.com, linux-kernel@vger.kernel.org
Subject: Re: WARN_ON_ONCE() in process_one_work()?
Date: Mon, 1 May 2017 14:44:02 -0400 [thread overview]
Message-ID: <20170501184402.GB8921@htj.duckdns.org> (raw)
In-Reply-To: <20170501183807.GA7054@linux.vnet.ibm.com>
Hello, Paul.
On Mon, May 01, 2017 at 11:38:07AM -0700, Paul E. McKenney wrote:
> On Mon, May 01, 2017 at 09:57:47AM -0700, Paul E. McKenney wrote:
> > Hello!
> >
> > I am hitting this WARN_ON_ONCE() in process_one_work() and am wondering
> > what I did wrong to make this happen:
>
> Oh, wait... Rescuer, it says. Might this be due to the fact that RCU's
> expedited grace periods block within a workqueue handler? Might this
> in turn run the system out of workqueue kthreads? If this is the likely
> cause, my approach would be to rework the expected-grace-period workqueue
> handler to return when waiting for the grace period to complete, and to
> replace the current wakeup with a schedule_work() or something similar.
That should be completely fine. It could just be that the rescuer
path has a bug around CPU hotplug handling. Can you please confirm
either way on the cpuset usage?
Thanks.
--
tejun
next prev parent reply other threads:[~2017-05-01 18:44 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-01 16:57 WARN_ON_ONCE() in process_one_work()? Paul E. McKenney
2017-05-01 18:38 ` Paul E. McKenney
2017-05-01 18:44 ` Tejun Heo [this message]
2017-05-01 18:58 ` Paul E. McKenney
2017-05-05 17:11 ` Paul E. McKenney
2017-06-13 20:58 ` Tejun Heo
2017-06-13 22:31 ` Paul E. McKenney
2017-06-14 15:15 ` Paul E. McKenney
2017-06-15 15:38 ` Paul E. McKenney
2017-06-16 17:36 ` Paul E. McKenney
2017-06-17 11:53 ` Tejun Heo
2017-06-17 17:31 ` Paul E. McKenney
2017-06-18 10:40 ` Tejun Heo
2017-06-20 16:45 ` Paul E. McKenney
2017-06-21 15:30 ` Paul E. McKenney
2017-06-23 16:41 ` Paul E. McKenney
2017-06-27 16:27 ` Paul E. McKenney
2017-05-01 18:42 ` Tejun Heo
2017-05-01 19:42 ` Steven Rostedt
2017-05-01 19:50 ` Tejun Heo
2017-05-01 20:02 ` Steven Rostedt
2018-06-20 19:29 Paul E. McKenney
2018-07-02 21:05 ` Tejun Heo
2018-07-03 4:05 ` Paul E. McKenney
2018-07-03 16:40 ` Paul E. McKenney
2018-07-03 20:12 ` Tejun Heo
2018-07-03 21:44 ` Paul E. McKenney
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