Re: [BUG almost bisected] Splat in dequeue_rt_stack() and build error

Paul E. McKenney
2024-09-13T18:00:41Z

On Fri, Sep 13, 2024 at 06:55:34PM +0200, Valentin Schneider wrote:
> On 13/09/24 07:08, Paul E. McKenney wrote:
> > On Sun, Sep 08, 2024 at 09:32:18AM -0700, Paul E. McKenney wrote:
> >>
> >> Just following up...
> >>
> >> For whatever it is worth, on last night's run of next-20240906, I got
> >> nine failures out of 100 6-hour runs of rcutorture’s TREE03 scenario.
> >> These failures were often, but not always, shortly followed by a hard hang.
> >>
> >> The warning at line 1995 is the WARN_ON_ONCE(on_dl_rq(dl_se))
> >> in enqueue_dl_entity() and the warning at line 1971 is the
> >> WARN_ON_ONCE(!RB_EMPTY_NODE(&dl_se->rb_node)) in __enqueue_dl_entity().
> >>
> >> The pair of splats is shown below, in case it helps.
> >
> > Again following up...
> >
> > I am still seeing this on next-20240912, with six failures out of 100
> > 6-hour runs of rcutorture’s TREE03 scenario. Statistics suggests that
> > we not read much into the change in frequency.
> >
> > Please let me know if there are any diagnostic patches or options that
> > I should apply.
>
> Hey, sorry I haven't forgotten about this, I've just spread myself a bit
> too thin and also apparently I'm supposed to prepare some slides for next
> week, I'll get back to this soonish.

I know that feeling! Just didn't want it to get lost.

Thanx, Paul