From: Zi Yan <ziy@xxxxxxxxxx> As Ying pointed out in [1], stats->nr_thp_failed needs to be updated to avoid stats inconsistency between MIGRATE_SYNC and MIGRATE_ASYNC when calling migrate_pages_batch(). [1] https://lore.kernel.org/linux-mm/87msnq7key.fsf@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ Suggested-by: "Huang, Ying" <ying.huang@xxxxxxxxx> Signed-off-by: Zi Yan <ziy@xxxxxxxxxx> --- mm/migrate.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/migrate.c b/mm/migrate.c index 2cc5a68f6843..20cb9f5f7446 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1659,6 +1659,10 @@ static int migrate_pages_batch(struct list_head *from, * 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() @@ -1675,6 +1679,7 @@ static int migrate_pages_batch(struct list_head *from, !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; base-commit: 14d7c92f8df9c0964ae6f8b813c1b3ac38120825 -- 2.43.0
