Re: 4.19.5 and later has tons of false messages "BUG: non-zero pgtables_bytes on freeing mm: -16384"

[Sasha Levin]

On Thu, Dec 27, 2018 at 10:06:09PM +0100, Christian Borntraeger wrote:
> On 12/27/2018 10:01 PM, Sasha Levin wrote:
> > On Thu, Dec 27, 2018 at 10:28:56AM +0100, Christian Borntraeger wrote:
> > > On 27.12.2018 10:13, Christian Borntraeger wrote:
> > > > Martin,
> > > >
> > > > Right now you get a message
> > > > "BUG: non-zero pgtables_bytes on freeing mm: -16384"
> > > > for EVERY process that exits in 4.19.5 and later.
> > > >
> > > > bisect points to
> > > > commit 4136161d676a93fc8df6bdb80d720c15522d6c24
> > > > Author: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
> > > > Date:   Mon Oct 15 11:09:16 2018 +0200
> > > >
> > > >     s390/mm: fix mis-accounting of pgtable_bytes
> > > >
> > > >     [ Upstream commit e12e4044aede97974f2222eb7f0ed726a5179a32 ]
> > > >
> > > > Turns out that this patch requires several dependencies so the autoselection of this
> > > > patch was missing that.
> > > >
> > > > Can we either revert this patch or add the dependencies?
> > > >
> > > > Christian
> > >
> > > It seems that adding
> > >
> > > commit 6d212db11947ae5464e4717536ed9faf61c01e86 ("mm: add mm_pxd_folded checks to pgtable_bytes accounting functions")
> > > fixes the issue.
> >
> > I've queued 6d212db11947 for 4.19 for now, thank you.
>
> Not sure, but you might need
> 1071fc5779d98 mm: introduce mm_[p4d|pud|pmd]_folded
> a8874e7e8a889 mm: make the __PAGETABLE_PxD_FOLDED defines non-empty
>
> to avoid compile errors on !s390.

Queued those for 4.19 as well, build looks clean.

--
Thanks,
Sasha