I forgot to CC stable on this fix. Chris On Thu, Sep 5, 2024 at 1:08 AM Chris Li <chrisl@xxxxxxxxxx> wrote: > > 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> >
