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).

From: Sander Eikelenboom
Date: Thu Jun 17 2021 - 08:36:02 EST


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