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-rw-r--r--mm/migrate.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index ab9856f5931b..63c97bb639d7 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1653,6 +1653,29 @@ static int migrate_pages_batch(struct list_head *from,
cond_resched();
/*
+ * The rare folio on the deferred split list should
+ * be split now. It should not count as a failure.
+ * 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
+ * corruption. Folio split process below can handle it
+ * with the help of folio_ref_freeze().
+ *
+ * nr_pages > 2 is needed to avoid checking order-1
+ * page cache folios. They exist, in contrast to
+ * non-existent order-1 anonymous folios, and do not
+ * use _deferred_list.
+ */
+ if (nr_pages > 2 &&
+ !list_empty(&folio->_deferred_list)) {
+ if (try_split_folio(folio, split_folios) == 0) {
+ stats->nr_thp_split += is_thp;
+ stats->nr_split++;
+ continue;
+ }
+ }
+
+ /*
* Large folio migration might be unsupported or
* the allocation might be failed so we should retry
* on the same folio with the large folio split