diff options
| author | Zi Yan <ziy@nvidia.com> | 2026-07-09 14:06:03 -0400 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-08-04 19:18:33 -0700 |
| commit | d007658032970db4979ea483a2dcd5658f0184cc (patch) | |
| tree | 74e2200f61f1d85de770fc51c91a9f23797c3b8d | |
| parent | 7ae5a5d8eca5eb7dd12c9d08e2cba1b2d8cf75e4 (diff) | |
mm/huge_memory: add page->private check back in __split_folio_to_order()
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/13f3fcda-7328-4aa5-afc6-75a294a82b2a@nvidia.com/ [1]
Link: https://lore.kernel.org/20260709-keep-subpage-private-zero-at-free-v3-3-7e4fe155f5b9@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/huge_memory.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 2289a0416cdc..7f3c53c0d3d4 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3591,6 +3591,13 @@ static void __split_folio_to_order(struct folio *folio, int old_order, 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; |