diff options
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index b1b91d5b9f49..95ebcb5b3e12 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1502,6 +1502,22 @@ static unsigned int demote_page_list(struct list_head *demote_pages, return nr_succeeded; } +static bool may_enter_fs(struct page *page, gfp_t gfp_mask) +{ + if (gfp_mask & __GFP_FS) + return true; + if (!PageSwapCache(page) || !(gfp_mask & __GFP_IO)) + return false; + /* + * We can "enter_fs" for swap-cache with only __GFP_IO + * providing this isn't SWP_FS_OPS. + * ->flags can be updated non-atomicially (scan_swap_map_slots), + * but that will never affect SWP_FS_OPS, so the data_race + * is safe. + */ + return !data_race(page_swap_flags(page) & SWP_FS_OPS); +} + /* * shrink_page_list() returns the number of reclaimed pages */ @@ -1528,7 +1544,7 @@ retry: struct page *page; struct folio *folio; enum page_references references = PAGEREF_RECLAIM; - bool dirty, writeback, may_enter_fs; + bool dirty, writeback; unsigned int nr_pages; cond_resched(); @@ -1553,9 +1569,6 @@ retry: if (!sc->may_unmap && page_mapped(page)) goto keep_locked; - may_enter_fs = (sc->gfp_mask & __GFP_FS) || - (PageSwapCache(page) && (sc->gfp_mask & __GFP_IO)); - /* * The number of dirty pages determines if a node is marked * reclaim_congested. kswapd will stall and start writing @@ -1598,7 +1611,7 @@ retry: * not to fs). In this case mark the page for immediate * reclaim and continue scanning. * - * Require may_enter_fs because we would wait on fs, which + * Require may_enter_fs() because we would wait on fs, which * may not have submitted IO yet. And the loop driver might * enter reclaim, and deadlock if it waits on a page for * which it is needed to do the write (loop masks off @@ -1630,7 +1643,7 @@ retry: /* Case 2 above */ } else if (writeback_throttling_sane(sc) || - !PageReclaim(page) || !may_enter_fs) { + !PageReclaim(page) || !may_enter_fs(page, sc->gfp_mask)) { /* * This is slightly racy - end_page_writeback() * might have just cleared PageReclaim, then @@ -1720,8 +1733,6 @@ retry: goto activate_locked_split; } - may_enter_fs = true; - /* Adding to swap updated mapping */ mapping = page_mapping(page); } @@ -1792,7 +1803,7 @@ retry: if (references == PAGEREF_RECLAIM_CLEAN) goto keep_locked; - if (!may_enter_fs) + if (!may_enter_fs(page, sc->gfp_mask)) goto keep_locked; if (!sc->may_writepage) goto keep_locked; |