On Tue, 2019-08-13 at 14:14 -0700, Stefano Stabellini wrote:
> On Tue, 13 Aug 2019, Dario Faggioli wrote:
> > 
> > I am attaching an updated debug patch, with an additional printk
> > when
> > we reach the point, within the null scheduler, when the vcpu would
> > wake
> > up (to check whether the problem is that we never reach that point,
> > or
> > something else).
> 
> See attached.
>
Ok, so we're not missing an "online call" nor a wakeup.

As Julien has identified, we seem to be stuck in a loop.

Now, while staring at the code of that loop, I've seen that pick_cpu()
may mess up with the scratch cpumask for the CPU, which I don't think
is a good thing.

So, can you also try this third debug-patch?

Thanks and Regards
-- 
Dario Faggioli, Ph.D
http://about.me/dario.faggioli
Virtualization Software Engineer
SUSE Labs, SUSE https://www.suse.com/
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