Re: Regression with kernel 6.3 "kernel BUG at include/linux/swapops.h:472!"

Helge Deller
2023-05-11T17:37:05Z

On 5/11/23 19:22, Christoph Biedl wrote:
> Helge Deller wrote...
>
>> I haven't used kernel 6.3 much yet, but the kernel BUG below seems
>> to be triggered by CONFIG_MIGRATION.
>> You could try to disable that config option first to verify if
>> it fixes your crash.
>> This might help to narrow down the problem....
>
> Looks good, still have a running system after 45 minutes, never got that
> far with the initial kernel configuration.

Good!

> In the meantime I realized only some 16 commits between v6.2 and v6.3
> affect arch/parisc. Do you think it's worth check right around those?

Don't think so.
Very unlikely is this one:
commit 88d7b12068b95731c280af8ce88e8ee9561f96de
highmem: round down the address passed to kunmap_flush_on_unmap()

> Also, if you can think of a way to trigger the crashes, that would ease
> the testing a lot.

Since you run the 32-bit kernel, huge-pages are not involved as they
aren't available in the 32-bit kernels.
So I think swapping is triggering it.
You could try to find a test program which triggers swapping, e.g. LTS testcases?
Another test could be to enable CONFIG_MIGRATION again and disable
all swap spaces and see if it survives.

Helge