Re: [PATCH 3/3] s390/mm: fix mis-accounting of pgtable_bytes

[Heiko Carstens]

On Wed, Oct 31, 2018 at 07:31:49AM +0100, Martin Schwidefsky wrote:
> Thanks for testing. Unfortunately Heiko reported another issue yesterday
> with the patch applied. This time the other way around:
> 
> BUG: non-zero pgtables_bytes on freeing mm: -16384
> 
> I am trying to understand how this can happen. For now I would like to
> keep the patch on hold in case they need another change.

FWIW, Kirill: is there a reason why this "BUG:" output is done with
pr_alert() and not with VM_BUG_ON() or one of the WARN*() variants?

That would to get more information with DEBUG_VM and / or
panic_on_warn=1 set. At least for automated testing it would be nice
to have such triggers.