diff options
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index dd04f578c19c..a8c6f466e33a 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -415,6 +415,15 @@ int folio_migrate_mapping(struct address_space *mapping, if (folio_ref_count(folio) != expected_count) return -EAGAIN; + /* Take off deferred split queue while frozen and memcg set */ + if (folio_test_large(folio) && + folio_test_large_rmappable(folio)) { + if (!folio_ref_freeze(folio, expected_count)) + return -EAGAIN; + folio_undo_large_rmappable(folio); + folio_ref_unfreeze(folio, expected_count); + } + /* No turning back from here */ newfolio->index = folio->index; newfolio->mapping = folio->mapping; @@ -433,6 +442,10 @@ int folio_migrate_mapping(struct address_space *mapping, return -EAGAIN; } + /* Take off deferred split queue while frozen and memcg set */ + if (folio_test_large(folio) && folio_test_large_rmappable(folio)) + folio_undo_large_rmappable(folio); + /* * Now we know that no one else is looking at the folio: * no turning back from here. @@ -1654,7 +1667,16 @@ static int migrate_pages_batch(struct list_head *from, /* * The rare folio on the deferred split list should - * be split now. It should not count as a failure. + * be split now. It should not count as a failure: + * but increment nr_failed because, without doing so, + * migrate_pages() may report success with (split but + * unmigrated) pages still on its fromlist; whereas it + * always reports success when its fromlist is empty. + * stats->nr_thp_failed should be increased too, + * otherwise stats inconsistency will happen when + * migrate_pages_batch is called via migrate_pages() + * with MIGRATE_SYNC and MIGRATE_ASYNC. + * * Only check it without removing it from the list. * Since the folio can be on deferred_split_scan() * local list and removing it can cause the local list @@ -1669,6 +1691,8 @@ static int migrate_pages_batch(struct list_head *from, if (nr_pages > 2 && !list_empty(&folio->_deferred_list)) { if (try_split_folio(folio, split_folios) == 0) { + nr_failed++; + stats->nr_thp_failed += is_thp; stats->nr_thp_split += is_thp; stats->nr_split++; continue; |