[merged mm-stable] mm-huge_memory-add-page-private-check-back-in-__split_folio_to_order.patch removed from -mm tree

The quilt patch titled
     Subject: mm/huge_memory: add page->private check back in __split_folio_to_order()
has been removed from the -mm tree.  Its filename was
     mm-huge_memory-add-page-private-check-back-in-__split_folio_to_order.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Zi Yan <[email protected]>
Subject: mm/huge_memory: add page->private check back in __split_folio_to_order()
Date: Thu, 09 Jul 2026 14:06:03 -0400

page->private should not be set in tail pages.  Commit 4265d67e405a
("mm/migrate_device: add THP splitting during migration") removed a
DEBUG_VM check without a proper reason[1].  Add it back.

Link: https://lore.kernel.org/all/[email protected]/ [1]
Link: https://lore.kernel.org/20260709-keep-subpage-private-zero-at-free-v3-3-7e4fe155f5b9@nvidia.com
Signed-off-by: Zi Yan <[email protected]>
Reviewed-by: Lance Yang <[email protected]>
Acked-by: David Hildenbrand (Arm) <[email protected]>
Reviewed-by: Baolin Wang <[email protected]>
Reviewed-by: Vlastimil Babka (SUSE) <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Dev Jain <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Nico Pache <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 mm/huge_memory.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/mm/huge_memory.c~mm-huge_memory-add-page-private-check-back-in-__split_folio_to_order
+++ a/mm/huge_memory.c
@@ -3591,6 +3591,13 @@ static void __split_folio_to_order(struc
 		new_folio->mapping = folio->mapping;
 		new_folio->index = folio->index + i;
 
+		/*
+		 * page->private should not be set in tail pages. Warn once
+		 * if private is unexpectedly set. Do it before swap.val assignment
+		 * since private overlaps with swap.val.
+		 */
+		VM_WARN_ON_ONCE_PAGE(new_folio->private, new_head);
+
 		if (folio_test_swapcache(folio))
 			new_folio->swap.val = folio->swap.val + i;
 
_

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

mm-huge_memory-use-folios-memcg-inside-__folio_split.patch
xarray-honor-xa_flags_account-in-xas_split_alloc.patch