+ mm-khugepaged-unmap-pte-before-releasing-vma-write-lock.patch added to mm-new branch

The patch titled
     Subject: mm/khugepaged: unmap pte before releasing vma write lock
has been added to the -mm mm-new branch.  Its filename is
     mm-khugepaged-unmap-pte-before-releasing-vma-write-lock.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-unmap-pte-before-releasing-vma-write-lock.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days

------------------------------------------------------
From: "Nico Pache (Red Hat)" <[email protected]>
Subject: mm/khugepaged: unmap pte before releasing vma write lock
Date: Tue, 04 Aug 2026 13:25:04 -0600

We are currently dropping the anon_vma write lock before unmapping the
PTE.  Although this is safe, due to us still holding the mmap_write_lock,
its safer and less confusing to switch the order of these two operations.

Link: https://lore.kernel.org/[email protected]
Signed-off-by: Nico Pache (Red Hat) <[email protected]>
Suggested-by: David Hildenbrand <[email protected]>
Acked-by: David Hildenbrand (Arm) <[email protected]>
Cc: Baolin Wang <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Dev Jain <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Lorenzo Stoakes (ARM) <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Usama Arif <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 mm/khugepaged.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/khugepaged.c~mm-khugepaged-unmap-pte-before-releasing-vma-write-lock
+++ a/mm/khugepaged.c
@@ -1546,10 +1546,10 @@ static enum scan_result collapse_huge_pa
 
 	result = SCAN_SUCCEED;
 out_up_write:
-	if (anon_vma_locked)
-		anon_vma_unlock_write(vma->anon_vma);
 	if (pte)
 		pte_unmap(pte);
+	if (anon_vma_locked)
+		anon_vma_unlock_write(vma->anon_vma);
 	mmap_write_unlock(mm);
 out_nolock:
 	if (folio)
_

Patches currently in -mm which might be from [email protected] are

mm-khugepaged-refactor-per-scan-state-clearing-into-collapse_control_init_scan.patch
mm-khugepaged-extract-young-page-check-into-pte_is_referenced-helper.patch
mm-khugepaged-introduce-a-count_collapse_event-helper.patch
mm-khugepaged-fix-outdated-comments.patch
mm-khugepaged-refactor-the-pte-state-checks-into-a-helper.patch
mm-khugepaged-unmap-pte-before-releasing-vma-write-lock.patch
mm-documentation-clarify-where-the-mthp-stats-live.patch