[ Upstream commit 0885ef4705607936fc36a38fd74356e1c465b023 ]

I found a regression on mm-unstable during my swap stress test, using tmpfs to compile linux. The test OOM very soon after the make spawns many cc processes.

It bisects down to this change: 33dfe9204f29b415bbc0abb1a50642d1ba94f5e9 (mm/gup: clear the LRU flag of a page before adding to LRU batch)

Yu Zhao propose the fix: "I think this is one of the potential side effects -- Huge mentioned earlier about isolate_lru_folios():"

I test that with it the swap stress test no longer OOM.

Link: https://lore.kernel.org/r/CAOUHufYi9h0kz5uW3LHHS3ZrVwEq-kKp8S6N-MZUmErNAXoXm... Link: https://lkml.kernel.org/r/20240905-lru-flag-v2-1-8a2d9046c594@kernel.org Fixes: 33dfe9204f29 ("mm/gup: clear the LRU flag of a page before adding to LRU batch") Signed-off-by: Chris Li chrisl@kernel.org Suggested-by: Yu Zhao yuzhao@google.com Suggested-by: Hugh Dickins hughd@google.com Closes: https://lore.kernel.org/all/CAF8kJuNP5iTj2p07QgHSGOJsiUfYpJ2f4R1Q5-3BN9JiD9W... Signed-off-by: Andrew Morton akpm@linux-foundation.org --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c index bd489c1af2289..a8d61a8b68944 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4300,7 +4300,7 @@ static bool sort_folio(struct lruvec *lruvec, struct folio *folio, struct scan_c }

/* ineligible */ - if (zone > sc->reclaim_idx) { + if (!folio_test_lru(folio) || zone > sc->reclaim_idx) { gen = folio_inc_gen(lruvec, folio, false); list_move_tail(&folio->lru, &lrugen->folios[gen][type][zone]); return true;

--- base-commit: 8e24a758d14c0b1cd42ab0aea980a1030eea811f change-id: 20241015-stable-oom-fix-a6ab273b1817

Best regards,