page fault while in kernel mode - after upgrade from 12.2 to 13.0

[Michael Schmiedgen]

On 05.05.2021 20:38, Mark Johnston wrote:
> On Wed, May 05, 2021 at 06:35:32PM +0200, Michael Schmiedgen wrote:
>> On 04.05.2021 21:02, Mark Johnston wrote:
>>> This looks like fairly random kernel memory corruption.  Are you able to
>>> build an INVARIANTS kernel and test that?  Assuming you're using 13.0,
>>> you'd grab the 13.0 sources, add "options INVARIANT_SUPPORT" and
>>> "options INVARIANTS" to the GENERIC kernel configuration in
>>> sys/amd64/conf, and do a "make buildkernel installkernel".
>>
>> Below some info with an INVARIANTS kernel. Please let me know if I can provide
>> further information. Thank you!
>
> Thanks, this helped a lot.  I believe https://reviews.freebsd.org/D30129
> will fix the problem.  That patch is against the main branch but applies
> cleanly to 13.0.

I applied the patch and the server is running fine now for 8 hours with the
INVARIANTS kernel, including the Samba jail and SIP VM. I just compiled my
custom kernel and it looks like it is working too. Are there plans to get
this MFCed or even as Errata?

BTW, we got 2 other systems, also with userland NAT but different workload.
After an uncertain amount of time, mostly weeks, the natd starts to spin 100%
CPU on these systems. Quick noobish workaround was restarting natd every night.
I saw your recent commits that applied some more safety in that area, do you
plan to MFC these as well? I can imagine that could help with my NAT problems.

Anyway, many thanks for your investigation and your fix, much appreciated!

   Michael