On Tue, 15 Oct 2024 22:55:23 -0600 Yu Zhao <yuzhao@xxxxxxxxxx> wrote: > > @@ -257,7 +258,9 @@ static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, > > gen = lru_gen_from_seq(seq); > > flags = (gen + 1UL) << LRU_GEN_PGOFF; > > /* see the comment on MIN_NR_GENS about PG_active */ > > - set_mask_bits(&folio->flags, LRU_GEN_MASK | BIT(PG_active), flags); > > + mask = LRU_GEN_MASK | BIT(PG_active); > > + mask |= folio_test_active(folio) ? (LRU_REFS_MASK | LRU_REFS_FLAGS) : 0; > > We shouldn't clear PG_workingset here because it can affect PSI > accounting, if the activation is due to workingset refault. > > Also, nit: > mask = LRU_GEN_MASK; > if (folio_test_active(folio)) > mask |= LRU_REFS_MASK | BIT(PG_active) | BIT(PG_referenced); > Thanks, I'll drop this version of this patch. When resending, please include a full description of the userspace-visible effects of the original flaw, thanks.
