From: Kairui Song 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() unlocks the folio, then free_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 and unmapped here, so just directly call folio_free_swap() directly under the lock, unlock and drop the reference. This makes the swap cache freeing deterministic and the reference drop explicit. Signed-off-by: Kairui Song --- mm/huge_memory.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index b80d0db63225..39c91c8e5bc8 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -4304,14 +4304,16 @@ static int __folio_split(struct folio *folio, unsigned int new_order, 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 * after the split completes. */ - free_folio_and_swap_cache(new_folio); + if (is_swapcache) + folio_free_swap(new_folio); + folio_unlock(new_folio); + folio_put(new_folio); } out: -- 2.55.0