[merged mm-stable] mm-mglru-batch-move-folios-to-the-second-oldest-gens-lru.patch removed from -mm tree

[merged mm-stable] mm-mglru-batch-move-folios-to-the-second-oldest-gens-lru.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/mglru: batch move folios to the second-oldest gen's LRU
has been removed from the -mm tree.  Its filename was
     mm-mglru-batch-move-folios-to-the-second-oldest-gens-lru.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: "Barry Song (Xiaomi)" <baohua@kernel.org>
Subject: mm/mglru: batch move folios to the second-oldest gen's LRU
Date: Wed, 2 Sep 2026 07:24:21 +0800

Detect folios that need to move from the oldest generation to the
second-oldest generation, and batch-move them together.  This can
significantly reduce the sys time of inc_min_seq(), especially when the
other type is significantly behind the preferred type.

Link: https://lore.kernel.org/20260901232421.40157-8-baohua@kernel.org
Signed-off-by: Barry Song (Xiaomi) <baohua@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <baoquan.he@linux.dev>
Tested-by: Xueyuan Chen <xueyuan.chen21@gmail.com>
Reviewed-by: Lian Wang <lianux.mm@gmail.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Assisted-by: gemini:gemini-3.6-flash
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Stevens <stevensd@chromium.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kunwu Chan <kunwu.chan@gmail.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Ridong Chen <ridong.chen@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
---

 mm/vmscan.c |   20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

--- a/mm/vmscan.c~mm-mglru-batch-move-folios-to-the-second-oldest-gens-lru
+++ a/mm/vmscan.c
@@ -3936,6 +3936,19 @@ static void clear_mm_walk(void)
 		kfree(walk);
 }
 
+static inline void flush_lru_batch(struct list_head *head, struct list_head **batch_end,
+				   struct list_head *dst)
+{
+	LIST_HEAD(movable);
+
+	if (!*batch_end)
+		return;
+
+	list_cut_position(&movable, head, *batch_end);
+	list_splice_tail_init(&movable, dst);
+	*batch_end = NULL;
+}
+
 static bool inc_min_seq(struct lruvec *lruvec, int type, int swappiness)
 {
 	int zone;
@@ -3958,8 +3971,10 @@ static bool inc_min_seq(struct lruvec *l
 			lru_gen_is_active(lruvec, target_gen));
 	/* prevent cold/hot inversion if the type is evictable */
 	for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+		struct list_head *target_list = &lrugen->folios[target_gen][type][zone];
 		struct list_head *head = &lrugen->folios[old_gen][type][zone];
 		struct list_head *pos = head->next;
+		struct list_head *batch_end = NULL;
 		long delta = 0;
 
 		while (pos != head) {
@@ -3984,7 +3999,7 @@ static bool inc_min_seq(struct lruvec *l
 			 */
 			if (gen_increased) {
 				delta += nr_pages;
-				list_move_tail(&folio->lru, &lrugen->folios[new_gen][type][zone]);
+				batch_end = &folio->lru;
 
 				/* don't count the workingset being lazily promoted */
 				if (refs + workingset != BIT(LRU_REFS_WIDTH) + 1) {
@@ -3994,11 +4009,14 @@ static bool inc_min_seq(struct lruvec *l
 						   lrugen->protected[hist][type][tier] + nr_pages);
 				}
 			} else {
+				flush_lru_batch(head, &batch_end, target_list);
 				list_move(&folio->lru, &lrugen->folios[new_gen][type][zone]);
 			}
 			if (!--remaining)
 				break;
 		}
+		flush_lru_batch(head, &batch_end, target_list);
+
 		WRITE_ONCE(lrugen->nr_pages[old_gen][type][zone],
 			   lrugen->nr_pages[old_gen][type][zone] - delta);
 		WRITE_ONCE(lrugen->nr_pages[target_gen][type][zone],
_

Patches currently in -mm which might be from baohua@kernel.org are

mm-mglru-restore-accidentally-removed-seq-max_seq-check.patch