We don't need to check can_split_folio() because folio_maybe_dma_pinned()
is checked before. It will avoid the long term pinned pages to be swapped
out. And we can live with short term pinned pages. Without can_split_folio
checking we can simplify the code. Also activate_locked can be changed to
keep_locked as it's just short term pinning.
Suggested-by: Huang, Ying <ying.huang@xxxxxxxxx>
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/vmscan.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4a76be47bed1..01f5db75a507 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1711,20 +1711,14 @@ static unsigned int shrink_page_list(struct list_head *page_list,
goto keep_locked;
if (folio_maybe_dma_pinned(folio))
goto keep_locked;
- if (PageTransHuge(page)) {
- /* cannot split THP, skip it */
- if (!can_split_folio(folio, NULL))
- goto activate_locked;
- /*
- * Split pages without a PMD map right
- * away. Chances are some or all of the
- * tail pages can be freed without IO.
- */
- if (!folio_entire_mapcount(folio) &&
- split_folio_to_list(folio,
- page_list))
- goto activate_locked;
- }
+ /*
+ * Split pages without a PMD map right
+ * away. Chances are some or all of the
+ * tail pages can be freed without IO.
+ */
+ if (PageTransHuge(page) && !folio_entire_mapcount(folio) &&
+ split_folio_to_list(folio, page_list))
+ goto keep_locked;
if (!add_to_swap(page)) {
if (!PageTransHuge(page))
goto activate_locked_split;
--
2.23.0
