+ mm-multi-gen-lru-use-mem_cgroup_lruvec-in-get_lruvec.patch added to mm-new branch

+ mm-multi-gen-lru-use-mem_cgroup_lruvec-in-get_lruvec.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm: multi-gen LRU: use mem_cgroup_lruvec() in get_lruvec()
has been added to the -mm mm-new branch.  Its filename is
     mm-multi-gen-lru-use-mem_cgroup_lruvec-in-get_lruvec.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-multi-gen-lru-use-mem_cgroup_lruvec-in-get_lruvec.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Siddharth Chintamaneni <sidchintamaneni@gmail.com>
Subject: mm: multi-gen LRU: use mem_cgroup_lruvec() in get_lruvec()
Date: Mon, 26 Oct 2026 20:23:12 +0000

Patch series "mm: multi-gen LRU: replace get_lruvec() with
mem_cgroup_lruvec()", v2.

This series cleans up MGLRU's get_lruvec() helper in mm/vmscan.c.

Patch 1 updates get_lruvec() to delegate to mem_cgroup_lruvec() rather
than returning &pgdat->__lruvec directly when memcg is disabled on the
kernel command line.

Patch 2 removes get_lruvec() completely and replaces all 15 call sites
with mem_cgroup_lruvec().


This patch (of 2):

Andrew Morton noted that get_lruvec() has the same pattern as
lru_gen_shrink_node(): when memcg is disabled on the command line
(cgroup_disable=memory), it returns &pgdat->__lruvec directly instead of
going through mem_cgroup_lruvec(), which initializes lruvec->pgdat.

In practice all callers of get_lruvec() run after kswapd_init() has
already initialized pgdat->__lruvec.pgdat on every N_MEMORY node, so
this is not a runtime bug. Have get_lruvec() delegate to
mem_cgroup_lruvec() directly.

Link: https://lore.kernel.org/20261026202313.63122-1-sidchintamaneni@gmail.com
Link: https://lore.kernel.org/20261026202313.63122-2-sidchintamaneni@gmail.com
Signed-off-by: Siddharth Chintamaneni <sidchintamaneni@gmail.com>
Signed-off-by: Hardik Garg <hargar@linux.microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <qi.zheng@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <apais@microsoft.com>
Cc: <rlmenge@gmail.com>
---

 mm/vmscan.c |   15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

--- a/mm/vmscan.c~mm-multi-gen-lru-use-mem_cgroup_lruvec-in-get_lruvec
+++ a/mm/vmscan.c
@@ -2866,20 +2866,9 @@ static struct lruvec *get_lruvec(struct
 {
 	struct pglist_data *pgdat = NODE_DATA(nid);
 
-#ifdef CONFIG_MEMCG
-	if (memcg) {
-		struct lruvec *lruvec = &memcg->nodeinfo[nid]->lruvec;
+	VM_WARN_ON_ONCE(!memcg && !mem_cgroup_disabled());
 
-		/* see the comment in mem_cgroup_lruvec() */
-		if (!lruvec->pgdat)
-			lruvec->pgdat = pgdat;
-
-		return lruvec;
-	}
-#endif
-	VM_WARN_ON_ONCE(!mem_cgroup_disabled());
-
-	return &pgdat->__lruvec;
+	return mem_cgroup_lruvec(memcg, pgdat);
 }
 
 static int get_swappiness(struct lruvec *lruvec, struct scan_control *sc)
_

Patches currently in -mm which might be from sidchintamaneni@gmail.com are

mm-multi-gen-lru-use-mem_cgroup_lruvec-in-get_lruvec.patch
mm-multi-gen-lru-remove-get_lruvec.patch