Re: WARN_ON_ONCE() in process_one_work()?

From: Paul E. McKenney
Date: Wed Jun 14 2017 - 11:16:02 EST


On Tue, Jun 13, 2017 at 03:31:03PM -0700, Paul E. McKenney wrote:
> On Tue, Jun 13, 2017 at 04:58:37PM -0400, Tejun Heo wrote:
> > Hello, Paul.
> >
> > On Fri, May 05, 2017 at 10:11:59AM -0700, Paul E. McKenney wrote:
> > > Just following up... I have hit this bug a couple of times over the
> > > past few days. Anything I can do to help?
> >
> > My apologies for dropping the ball on this. I've gone over the hot
> > plug code in workqueue several times but can't really find how this
> > would happen. Can you please apply the following patch and see what
> > it says when the problem happens?
>
> I have fired it up, thank you!
>
> Last time I saw one failure in 21 hours of test runs, so I have kicked
> of 42 one-hour test runs. Will see what happens tomorrow morning,
> Pacific Time.

And none of the 42 runs resulted in a workqueue splat. I will try again
this evening, Pacific Time.

Who knows, maybe your diagnostic patch is the fix. ;-)

Thanx, Paul