On Wed, 14 Aug 2019, Dario Faggioli wrote:
> 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?

Yep, see attached