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

From: Hugh Dickins

Date: Mon Aug 24 2026 - 10:28:24 EST


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 <hughd@xxxxxxxxxx>
---
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