Re: Linux DomU freezes and dies under heavy memory shuffling

[Roman Shaposhnik <roman@xxxxxxxxxx>]

Hi Jürgen, thanks for taking a look at this. A few comments below:

On Tue, Feb 16, 2021 at 10:47 PM Jürgen Groß <jgross@xxxxxxxx> wrote:
>
> On 16.02.21 21:34, Stefano Stabellini wrote:
> > + x86 maintainers
> >
> > It looks like the tlbflush is getting stuck?
>
> I have seen this case multiple times on customer systems now, but
> reproducing it reliably seems to be very hard.

It is reliably reproducible under my workload but it take a long time
(~3 days of the workload running in the lab).

> I suspected fifo events to be blamed, but just yesterday I've been
> informed of another case with fifo events disabled in the guest.
>
> One common pattern seems to be that up to now I have seen this effect
> only on systems with Intel Gold cpus. Can it be confirmed to be true
> in this case, too?

I am pretty sure mine isn't -- I can get you full CPU specs if that's useful.

> In case anybody has a reproducer (either in a guest or dom0) with a
> setup where a diagnostic kernel can be used, I'd be _very_ interested!

I can easily add things to Dom0 and DomU. Whether that will disrupt the
experiment is, of course, another matter. Still please let me know what
would be helpful to do.

Thanks,
Roman.