[PATCH v6 12/15] mm/mglru: Reduce LRU lock contention by shrinking folio batches in inc_min_seq

[Barry Song (Xiaomi)]

Reduce the number of folios moved from the oldest generation to the
second-oldest generation in each batch. This shortens the time the
lruvec lock is held, allowing concurrent LRU operations to make
progress and significantly reducing LRU lock contention.

Signed-off-by: Barry Song (Xiaomi) <baohua@xxxxxxxxxx>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bfc9789a999a..34faabe617ae 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3911,7 +3911,7 @@ static inline void flush_lru_batch(struct list_head *head, struct list_head **ba
 static bool inc_min_seq(struct lruvec *lruvec, int type, int swappiness)
 {
 	int zone;
-	int remaining = MAX_LRU_BATCH;
+	int remaining = MIN_LRU_BATCH;
 	struct lru_gen_folio *lrugen = &lruvec->lrugen;
 	int hist = lru_hist_from_seq(lrugen->min_seq[type]);
 	int new_gen, old_gen = lru_gen_from_seq(lrugen->min_seq[type]);
-- 
2.34.1