diff options
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 52 |
1 files changed, 34 insertions, 18 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 3ef654addd44..2e34de9cd0d4 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -967,7 +967,8 @@ static unsigned int demote_folio_list(struct list_head *demote_folios, .gfp_mask = (GFP_HIGHUSER_MOVABLE & ~__GFP_RECLAIM) | __GFP_NOWARN | __GFP_NOMEMALLOC | GFP_NOWAIT, .nid = target_nid, - .nmask = &allowed_mask + .nmask = &allowed_mask, + .reason = MR_DEMOTION, }; if (list_empty(demote_folios)) @@ -1205,25 +1206,28 @@ retry: if (!can_split_folio(folio, NULL)) goto activate_locked; /* - * Split folios without a PMD map right - * away. Chances are some or all of the - * tail pages can be freed without IO. + * Split partially mapped folios right away. + * We can free the unmapped pages without IO. */ - if (!folio_entire_mapcount(folio) && - split_folio_to_list(folio, - folio_list)) + if (data_race(!list_empty(&folio->_deferred_list)) && + split_folio_to_list(folio, folio_list)) goto activate_locked; } if (!add_to_swap(folio)) { + int __maybe_unused order = folio_order(folio); + if (!folio_test_large(folio)) goto activate_locked_split; /* Fallback to swap normal pages */ - if (split_folio_to_list(folio, - folio_list)) + if (split_folio_to_list(folio, folio_list)) goto activate_locked; #ifdef CONFIG_TRANSPARENT_HUGEPAGE - count_memcg_folio_events(folio, THP_SWPOUT_FALLBACK, 1); - count_vm_event(THP_SWPOUT_FALLBACK); + if (nr_pages >= HPAGE_PMD_NR) { + count_memcg_folio_events(folio, + THP_SWPOUT_FALLBACK, 1); + count_vm_event(THP_SWPOUT_FALLBACK); + } + count_mthp_stat(order, MTHP_STAT_SWPOUT_FALLBACK); #endif if (!add_to_swap(folio)) goto activate_locked_split; @@ -1256,6 +1260,20 @@ retry: if (folio_test_pmd_mappable(folio)) flags |= TTU_SPLIT_HUGE_PMD; + /* + * Without TTU_SYNC, try_to_unmap will only begin to + * hold PTL from the first present PTE within a large + * folio. Some initial PTEs might be skipped due to + * races with parallel PTE writes in which PTEs can be + * cleared temporarily before being written new present + * values. This will lead to a large folio is still + * mapped while some subpages have been partially + * unmapped after try_to_unmap; TTU_SYNC helps + * try_to_unmap acquire PTL from the first PTE, + * eliminating the influence of temporary PTE values. + */ + if (folio_test_large(folio) && list_empty(&folio->_deferred_list)) + flags |= TTU_SYNC; try_to_unmap(folio, flags); if (folio_mapped(folio)) { @@ -2091,8 +2109,7 @@ static void shrink_active_list(unsigned long nr_to_scan, } static unsigned int reclaim_folio_list(struct list_head *folio_list, - struct pglist_data *pgdat, - bool ignore_references) + struct pglist_data *pgdat) { struct reclaim_stat dummy_stat; unsigned int nr_reclaimed; @@ -2105,7 +2122,7 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, .no_demotion = 1, }; - nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &dummy_stat, ignore_references); + nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &dummy_stat, true); while (!list_empty(folio_list)) { folio = lru_to_folio(folio_list); list_del(&folio->lru); @@ -2115,7 +2132,7 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, return nr_reclaimed; } -unsigned long reclaim_pages(struct list_head *folio_list, bool ignore_references) +unsigned long reclaim_pages(struct list_head *folio_list) { int nid; unsigned int nr_reclaimed = 0; @@ -2137,12 +2154,11 @@ unsigned long reclaim_pages(struct list_head *folio_list, bool ignore_references continue; } - nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid), - ignore_references); + nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid)); nid = folio_nid(lru_to_folio(folio_list)); } while (!list_empty(folio_list)); - nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid), ignore_references); + nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid)); memalloc_noreclaim_restore(noreclaim_flag); |