mm: vmscan.c: fix OOM on swap stress test

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: 33dfe9204f
(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@mail.gmail.com/
Link: https://lkml.kernel.org/r/20240905-lru-flag-v2-1-8a2d9046c594@kernel.org
Fixes: 33dfe9204f ("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_KA@mail.gmail.com/
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Chris Li 2024-09-05 01:08:17 -07:00 committed by Andrew Morton
parent 35fccce29f
commit 0885ef4705

View File

@ -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;