Re: [PATCH v5 0/6] add mTHP support for anonymous shmem

From: Matthew Wilcox
Date: Thu Jul 04 2024 - 15:49:49 EST


On Thu, Jul 04, 2024 at 09:19:10PM +0200, David Hildenbrand wrote:
> On 04.07.24 21:03, David Hildenbrand wrote:
> > > shmem has two uses:
> > >
> > > - MAP_ANONYMOUS | MAP_SHARED (this patch set)
> > > - tmpfs
> > >
> > > For the second use case we don't want controls *at all*, we want the
> > > same heiristics used for all other filesystems to apply to tmpfs.
> >
> > As discussed in the MM meeting, Hugh had a different opinion on that.
>
> FWIW, I just recalled that I wrote a quick summary:
>
> https://lkml.kernel.org/r/f1783ff0-65bd-4b2b-8952-52b6822a0835@xxxxxxxxxx
>
> I believe the meetings are recorded as well, but never looked at recordings.

That's not what I understood Hugh to mean. To me, it seemed that Hugh
was expressing an opinion on using shmem as shmem, not as using it as
tmpfs.

If I misunderstood Hugh, well, I still disagree. We should not have
separate controls for this. tmpfs is just not that special.