[PATCH 4/8] mm/swap: Use PG_dropbehind instead of PG_reclaim

[Kirill A. Shutemov]

The recently introduced PG_dropbehind allows for freeing folios
immediately after writeback. Unlike PG_reclaim, it does not need vmscan
to be involved to get the folio freed.

Instead of using folio_set_reclaim(), use folio_set_dropbehind() in
lru_deactivate_file().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
 mm/swap.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/mm/swap.c b/mm/swap.c
index fc8281ef4241..4eb33b4804a8 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -562,14 +562,8 @@ static void lru_deactivate_file(struct lruvec *lruvec, struct folio *folio)
 	folio_clear_referenced(folio);
 
 	if (folio_test_writeback(folio) || folio_test_dirty(folio)) {
-		/*
-		 * Setting the reclaim flag could race with
-		 * folio_end_writeback() and confuse readahead.  But the
-		 * race window is _really_ small and  it's not a critical
-		 * problem.
-		 */
 		lruvec_add_folio(lruvec, folio);
-		folio_set_reclaim(folio);
+		folio_set_dropbehind(folio);
 	} else {
 		/*
 		 * The folio's writeback ended while it was in the batch.
-- 
2.45.2