From 47932e7048df9156e96133ee90fb3e9df68dbd15 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 11 Mar 2024 19:18:34 +0000 Subject: mm: remove folio from deferred split list before uncharging it When freeing a large folio, we must remove it from the deferred split list before we uncharge it as each memcg has its own deferred split list (with associated lock) and removing a folio from the deferred split list while holding the wrong lock will corrupt that list and cause various related problems. Link: https://lore.kernel.org/linux-mm/367a14f7-340e-4b29-90ae-bc3fcefdd5f4@arm.com/ Link: https://lkml.kernel.org/r/20240311191835.312162-1-willy@infradead.org Fixes: f77171d241e3 (mm: allow non-hugetlb large folios to be batch processed) Fixes: 29f3843026cf (mm: free folios directly in move_folios_to_lru()) Fixes: bc2ff4cbc329 (mm: free folios in a batch in shrink_folio_list()) Signed-off-by: Matthew Wilcox (Oracle) Debugged-by: Ryan Roberts Tested-by: Ryan Roberts Signed-off-by: Andrew Morton --- mm/swap.c | 3 +++ mm/vmscan.c | 6 ++++++ 2 files changed, 9 insertions(+) (limited to 'mm') diff --git a/mm/swap.c b/mm/swap.c index 6b697d33fa5b..e43a5911b170 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -1012,6 +1012,9 @@ void folios_put_refs(struct folio_batch *folios, unsigned int *refs) free_huge_folio(folio); continue; } + if (folio_test_large(folio) && + folio_test_large_rmappable(folio)) + folio_undo_large_rmappable(folio); __page_cache_release(folio, &lruvec, &flags); diff --git a/mm/vmscan.c b/mm/vmscan.c index e3349b75f15b..61606fa83504 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1413,6 +1413,9 @@ free_it: */ nr_reclaimed += nr_pages; + if (folio_test_large(folio) && + folio_test_large_rmappable(folio)) + folio_undo_large_rmappable(folio); if (folio_batch_add(&free_folios, folio) == 0) { mem_cgroup_uncharge_folios(&free_folios); try_to_unmap_flush(); @@ -1819,6 +1822,9 @@ static unsigned int move_folios_to_lru(struct lruvec *lruvec, if (unlikely(folio_put_testzero(folio))) { __folio_clear_lru_flags(folio); + if (folio_test_large(folio) && + folio_test_large_rmappable(folio)) + folio_undo_large_rmappable(folio); if (folio_batch_add(&free_folios, folio) == 0) { spin_unlock_irq(&lruvec->lru_lock); mem_cgroup_uncharge_folios(&free_folios); -- cgit