[to-be-updated] mm-huge_memory-clean-up-after-split-folio-freeing-in-__folio_split.patch removed from -mm tree

[to-be-updated] mm-huge_memory-clean-up-after-split-folio-freeing-in-__folio_split.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/huge_memory: clean up after-split folio freeing in __folio_split
has been removed from the -mm tree.  Its filename was
     mm-huge_memory-clean-up-after-split-folio-freeing-in-__folio_split.patch

This patch was dropped because an updated version will be issued

------------------------------------------------------
From: Kairui Song <kasong@tencent.com>
Subject: mm/huge_memory: clean up after-split folio freeing in __folio_split
Date: Tue, 15 Sep 2026 01:14:56 +0800

Replace free_folio_and_swap_cache() with an explicit folio_free_swap() and
folio_put() in the after-split loop.  free_folio_and_swap_cache() must
trylock it again and re-check folio_mapped() before freeing the swap cache
entries.  If the trylock loses a race, the entries are left behind even
though the folio reference is dropped.

The sub folios are still locked here, so just directly call
folio_free_swap() under the lock if it's unmapped, then unlock and drop
the reference.  This makes the swap cache freeing deterministic and the
reference drop explicit.

Link: https://lore.kernel.org/20260915-swap-thp-cleanup-v5-15-39878b37dfb0@tencent.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
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: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
---

 mm/huge_memory.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

--- a/mm/huge_memory.c~mm-huge_memory-clean-up-after-split-folio-freeing-in-__folio_split
+++ a/mm/huge_memory.c
@@ -4326,7 +4326,8 @@ static int __folio_split(struct folio *f
 		struct list_head *list, enum split_type split_type)
 {
 	struct folio *end_folio = folio_next(folio);
-	bool is_anon = folio_test_anon(folio);
+	const bool is_anon = folio_test_anon(folio);
+	const bool is_swapcache = folio_test_swapcache(folio);
 	int old_order = folio_order(folio);
 	struct folio *new_folio, *next;
 	int ret;
@@ -4366,14 +4367,16 @@ static int __folio_split(struct folio *f
 		if (new_folio == page_folio(lock_at))
 			continue;
 
-		folio_unlock(new_folio);
 		/*
 		 * Subpages whose mapping has been zapped may be freed
 		 * earlier, but freeing them requires taking the
-		 * lru_lock, so we defer put_page() on tail pages until
+		 * lru_lock, so we defer folio_put() on tail pages until
 		 * after the split completes.
 		 */
-		free_folio_and_swap_cache(new_folio);
+		if (is_swapcache && !folio_mapped(new_folio))
+			folio_free_swap(new_folio);
+		folio_unlock(new_folio);
+		folio_put(new_folio);
 	}
 
 out:
@@ -4400,7 +4403,7 @@ out:
  * isolated from LRU (if applicable)
  *
  * Upon return, the folio is not remapped, split folios are not added to LRU,
- * free_folio_and_swap_cache() is not called, and new folios remain locked.
+ * folio_free_swap() is not called, and new folios remain locked.
  *
  * Return: 0 on success, -EAGAIN if the folio cannot be split (e.g., due to
  *         insufficient reference count or extra pins).
_

Patches currently in -mm which might be from kasong@tencent.com are

mm-memcontrol-move-the-lru_zone_size-sanity-check-to-the-reader-side.patch
mm-mglru-introduce-helpers-for-manipulating-gen-and-refs-flags.patch
mm-migrate-copy-all-referenced-state-via-folio_migrate_lru_refs.patch
mm-mglru-move-max_seq-read-into-walk_update_folio.patch
mm-mglru-use-explicit-tier-range-in-read_ctrl_pos.patch
mm-mglru-fix-potential-generation-folio-number-leak.patch
mm-huge_memory-count-only-swap-cache-refs-in-anon-folio-split.patch
mm-huge_memory-drop-the-redundant-mapping-argument-of-__split_frozen_folio.patch