Re: [PATCH v4 0/4] hugetlb: Disable huge pmd unshare for uffd-wp

On Thu, Feb 18, 2021 at 06:06:29PM -0500, Peter Xu wrote:

v4:
- fix build for sparc by removing extra line in patch 1 [Mike]
- pick Mike's r-b for patch 4

v3:
- patch 4:
  - fix build failure for !CMA and/or !HUGETLBFS [Axel]
  - Fix mmu notifier range to use start/end [Mike]
- add more r-bs

v2:
- patch 4: move hugetlb_unshare_all_pmds() into mm/hugetlb.c, so it can be used
  even outside userfaultfd.c

This series tries to disable huge pmd unshare of hugetlbfs backed memory for
uffd-wp.  Although uffd-wp of hugetlbfs is still during rfc stage, the idea of
this series may be needed for multiple tasks (Axel's uffd minor fault series,
and Mike's soft dirty series), so I picked it out from the larger series.

References works:

Uffd shmem+hugetlbfs rfc:
https://lore.kernel.org/lkml/20210115170907.24498-1-peterx@redhat.com/ (local)

Uffd minor mode for hugetlbfs:
https://lore.kernel.org/lkml/20210212215403.3457686-1-axelrasmussen@google.com/ (local)

Soft dirty for hugetlbfs:
https://lore.kernel.org/lkml/20210211000322.159437-1-mike.kravetz@oracle.com/ (local)

Andrew/Mike,

Do you have any further comment on this series?

Thanks,

-- 
Peter Xu