Re: Linux 5.13-rc6 regression to 5.12.x: kernel OOM and panic during kernel boot in low memory Xen VM's (256MB assigned memory).

[Sander Eikelenboom <linux@xxxxxxxxxxxxxx>]

On 17/06/2021 12:30, Juergen Gross wrote:
> On 17.06.21 11:26, Sander Eikelenboom wrote:
> > L.S.,
> >
> > I just tried to upgrade and test the linux kernel going from the 5.12
> > kernel series to 5.13-rc6 on my homeserver with Xen, but ran in some
> > trouble.
> >
> > Some VM's boot fine (with more than 256MB memory assigned), but the
> > smaller (memory wise) PVH ones crash during kernel boot due to OOM.
> > Booting VM's with 5.12(.9) kernel still works fine, also when dom0 is
> > running 5.13-rc6 (but it has more memory assigned, so that is not
> > unexpected).
> >
> > The 5.13-rc6'ish kernel is a pull of today, tried both with and without
> > last AKPM's patches, but that
> > makes no difference.
> >
> > Below are stacktraces from a few of the crashing VM's.
> >
> > Attached is the kernel .config
> >
> > Any pointers ?
> Did you compare memory usage with a bootable guest between kernel 5.12
> and 5.13-rc6?
>
> Any chance you could bisect?
>
>
> Juergen
Yeah a bisection is already underway, still 10 steps to go ...

--
Sander