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-MZUmErNAXoXmw@xxxxxxxxxxxxxx/ Fixes: 33dfe9204f29 ("mm/gup: clear the LRU flag of a page before adding to LRU batch") Suggested-by: Yu Zhao <yuzhao@xxxxxxxxxx> Suggested-by: Hugh Dickins <hughd@xxxxxxxxxx> Tested-by: Chris Li <chrisl@xxxxxxxxxx> Closes: https://lore.kernel.org/all/CAF8kJuNP5iTj2p07QgHSGOJsiUfYpJ2f4R1Q5-3BN9JiD9W_KA@xxxxxxxxxxxxxx/ Signed-off-by: Chris Li <chrisl@xxxxxxxxxx> --- Changes in v2: - Add Closes tag suggested by Yu and Thorsten. - Link to v1: https://lore.kernel.org/r/20240904-lru-flag-v1-1-36638d6a524c@xxxxxxxxxx --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index a9b6a8196f95..96abf4a52382 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4323,7 +4323,7 @@ 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: 756ca36d643324d028b325a170e73e392b9590cd change-id: 20240904-lru-flag-2af2f955740e Best regards, -- Chris Li <chrisl@xxxxxxxxxx>
