diff options
| author | Zi Yan <ziy@nvidia.com> | 2025-11-26 16:06:17 -0500 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-12-09 11:25:33 -0800 |
| commit | 2f78910659c72807b7ff03a2c0d121901bf55848 (patch) | |
| tree | b51e980a6130484f31831b7aa949ff8224cfcfd5 /include | |
| parent | 5842bcbfc316738cbfcbdb4def5a7592aa03ebf2 (diff) | |
mm/huge_memory: make min_order_for_split() always return an order
min_order_for_split() returns -EBUSY when the folio is truncated and
cannot be split. In commit 77008e1b2ef7 ("mm/huge_memory: do not change
split_huge_page*() target order silently"), memory_failure() does not
handle it and pass -EBUSY to try_to_split_thp_page() directly.
try_to_split_thp_page() returns -EINVAL since -EBUSY becomes 0xfffffff0 as
new_order is unsigned int in __folio_split() and this large new_order is
rejected as an invalid input. The code does not cause a bug.
soft_offline_in_use_page() also uses min_order_for_split() but it always
passes 0 as new_order for split.
Fix it by making min_order_for_split() always return an order. When the
given folio is truncated, namely folio->mapping == NULL, return 0 and let
a subsequent split function handle the situation and return -EBUSY.
Add kernel-doc to min_order_for_split() to clarify its use.
Link: https://lkml.kernel.org/r/20251126210618.1971206-4-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/huge_mm.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 8a52e20387b0..21162493a0a0 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -372,7 +372,7 @@ enum split_type { int __split_huge_page_to_list_to_order(struct page *page, struct list_head *list, unsigned int new_order); int folio_split_unmapped(struct folio *folio, unsigned int new_order); -int min_order_for_split(struct folio *folio); +unsigned int min_order_for_split(struct folio *folio); int split_folio_to_list(struct folio *folio, struct list_head *list); int folio_check_splittable(struct folio *folio, unsigned int new_order, enum split_type split_type); @@ -630,10 +630,10 @@ static inline int split_huge_page(struct page *page) return -EINVAL; } -static inline int min_order_for_split(struct folio *folio) +static inline unsigned int min_order_for_split(struct folio *folio) { VM_WARN_ON_ONCE_FOLIO(1, folio); - return -EINVAL; + return 0; } static inline int split_folio_to_list(struct folio *folio, struct list_head *list) |