Re: [PATCH v4] mm, drm/i915: mark pinned shmemfs pages as unevictable

[Kuo-Hsin Yang]

On Tue, Nov 6, 2018 at 2:52 AM Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
>
> On 11/5/18 3:13 AM, Kuo-Hsin Yang wrote:
> > -These are currently used in two places in the kernel:
> > +These are currently used in three places in the kernel:
> >
> >   (1) By ramfs to mark the address spaces of its inodes when they are created,
> >       and this mark remains for the life of the inode.
> > @@ -154,6 +154,8 @@ These are currently used in two places in the kernel:
> >       swapped out; the application must touch the pages manually if it wants to
> >       ensure they're in memory.
> >
> > + (3) By the i915 driver to mark pinned address space until it's unpinned.
>
> At a minimum, I think we owe some documentation here of how to tell
> approximately how much memory i915 is consuming with this mechanism.
> The debugfs stuff sounds like a halfway reasonable way to approximate
> it, although it's imperfect.

OK, I will add more comments here.