Re: [PATCH v8 0/5] Migrate on fault for device pages

[Andrew Morton]

On Tue, 14 Apr 2026 07:12:21 +0300 mpenttil@xxxxxxxxxx wrote:

> From: Mika Penttilä <mpenttil@xxxxxxxxxx>
> 
> Currently, the way device page faulting and migration works
> is not optimal, if you want to do both fault handling and
> migration at once.
> 
> Being able to migrate not present pages (or pages mapped with incorrect
> permissions, eg. COW) to the GPU requires doing either of the
> following sequences:
> 
> ...
>

Via which tree would it be best to upstream this?

>  include/linux/hmm.h                    |  19 +-
>  include/linux/migrate.h                |  26 +-
>  lib/test_hmm.c                         | 101 ++-
>  lib/test_hmm_uapi.h                    |  19 +-
>  mm/Kconfig                             |   2 +
>  mm/hmm.c                               | 821 +++++++++++++++++++++++--
>  mm/migrate_device.c                    | 589 +++---------------
>  tools/testing/selftests/mm/hmm-tests.c |  54 ++
>  8 files changed, 1053 insertions(+), 578 deletions(-)

Looks like mm.git.

It might be more useful to add it to a DRM tree if there's ongoing
development against this.  But please no upstreaming without good
review!

Anyway, this is a bit dated and Sashiko AI review wasn't able to apply
the patches.  Nor was it able to apply v7 or v6.  So please refresh,
retest, resend?