[PATCH 13/25] mm/fbatch: no lru_add_drain() to collect_longterm_unpinnable_folios()

collect_longterm_unpinnable_folios() has no use for lru_add_drain() nor
lru_add_drain_all(), now that the per-cpu fbatch references are gone.

Signed-off-by: Hugh Dickins <[email protected]>
---
 mm/gup.c | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index 99902c15703b..9616379ab069 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2268,7 +2268,6 @@ static unsigned long collect_longterm_unpinnable_folios(
 {
 	unsigned long collected = 0;
 	struct folio *folio;
-	int drained = 0;
 	long i = 0;
 
 	for (folio = pofs_get_folio(pofs, i); folio;
@@ -2287,19 +2286,6 @@ static unsigned long collect_longterm_unpinnable_folios(
 			continue;
 		}
 
-		if (drained == 0 && folio_may_be_lru_cached(folio) &&
-				folio_ref_count(folio) !=
-				folio_expected_ref_count(folio) + 1) {
-			lru_add_drain();
-			drained = 1;
-		}
-		if (drained == 1 && folio_may_be_lru_cached(folio) &&
-				folio_ref_count(folio) !=
-				folio_expected_ref_count(folio) + 1) {
-			lru_add_drain_all();
-			drained = 2;
-		}
-
 		if (!folio_isolate_lru(folio))
 			continue;
 
-- 
2.51.0