Page reclaim will not scan anon LRU if no swap space, however MADV_PAGEOUT
can still split shmem large folios even without a swap device. Thus add
swap available space validation before spliting shmem large folio to
avoid redundant split.
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1807e5d95dda..61465f92283f 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1237,6 +1237,14 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
}
} else if (folio_test_swapbacked(folio) &&
folio_test_large(folio)) {
+
+ /*
+ * Do not split shmem folio if no swap memory
+ * available.
+ */
+ if (!total_swap_pages)
+ goto activate_locked;
+
/* Split shmem folio */
if (split_folio_to_list(folio, folio_list))
goto keep_locked;
--
2.39.3
