[Intel-gfx] [PATCH 01/23] mm/shmem: introduce shmem_file_setup_with_mnt

[Andrew Morton]

On Thu, 24 Aug 2017 13:04:09 +0100 Matthew Auld <matthew.william.auld at gmail.com> wrote:

> On 23 August 2017 at 23:34, Andrew Morton <akpm at linux-foundation.org> wrote:
> > On Wed, 23 Aug 2017 12:31:28 +0300 Joonas Lahtinen <joonas.lahtinen at linux.intel.com> wrote:
> >
> >> This patch has been floating around for a while now Acked and without
> >> further comments. It is blocking us from merging huge page support to
> >> drm/i915.
> >>
> >> Would you mind merging it, or prodding the right people to get it in?
> >>
> >> Regards, Joonas
> >>
> >> On Mon, 2017-08-21 at 19:34 +0100, Matthew Auld wrote:
> >> > We are planning to use our own tmpfs mnt in i915 in place of the
> >> > shm_mnt, such that we can control the mount options, in particular
> >> > huge=, which we require to support huge-gtt-pages. So rather than roll
> >> > our own version of __shmem_file_setup, it would be preferred if we could
> >> > just give shmem our mnt, and let it do the rest.
> >
> > hm, it's a bit odd.  I'm having trouble locating the code which handles
> > huge=within_size (and any other options?).
> 
> See here https://patchwork.freedesktop.org/patch/172771/, currently we
> only care about huge=within_size.
> 
> > What other approaches were considered?
> 
> We also tried https://patchwork.freedesktop.org/patch/156528/, where
> it was suggested that we mount our own tmpfs instance.
> 
> Following from that we now have our own tmps mnt mounted with
> huge=within_size. With this patch we avoid having to roll our own
> __shmem_file_setup like in
> https://patchwork.freedesktop.org/patch/163024/.
> 
> > Was it not feasible to add i915-specific mount options to
> > mm/shmem.c (for example?).
> 
> Hmm, I think within_size should suffice for our needs.

hm, ok, well, unless someone can think of something cleaner, please add
my ack and include it in the appropriate drm tree.