Re: [PATCH v4 11/19] sched/core: Make migrate disable and CPU hotplug cooperative

[Qian Cai]

On Mon, 2020-11-23 at 19:13 +0100, Sebastian Andrzej Siewior wrote:
> On 2020-11-18 09:44:34 [-0500], Qian Cai wrote:
> > On Tue, 2020-11-17 at 19:28 +0000, Valentin Schneider wrote:
> > > We did have some breakage in that area, but all the holes I was aware of
> > > have been plugged. What would help here is to see which tasks are still
> > > queued on that outgoing CPU, and their recent activity.
> > > 
> > > Something like
> > > - ftrace_dump_on_oops on your kernel cmdline
> > > - trace-cmd start -e 'sched:*'
> > >  <start the test here>
> > > 
> > > ought to do it. Then you can paste the (tail of the) ftrace dump.
> > > 
> > > I also had this laying around, which may or may not be of some help:
> > 
> > Once I have found a reliable reproducer, I'll report back.
> 
> any update?

Just back from a vacation. I have been running the same workload on today's
linux-next for a few hours and it has been good so far. I'll surely report back
if it happens again in our daily runs.