[merged mm-stable] memcg-v1-bail-out-reclaim-when-memcg-is-dying.patch removed from -mm tree

The quilt patch titled
     Subject: memcg-v1: bail out reclaim when memcg is dying
has been removed from the -mm tree.  Its filename was
     memcg-v1-bail-out-reclaim-when-memcg-is-dying.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: Jiayuan Chen <[email protected]>
Subject: memcg-v1: bail out reclaim when memcg is dying
Date: Thu, 2 Jul 2026 20:02:30 +0800

The legacy memory.limit_in_bytes and memory.memsw.limit_in_bytes writers
retry page_counter_set_max() by reclaiming synchronously in the writer
context.  memory.force_empty similarly loops in synchronous reclaim until
the cgroup is empty or reclaim stops making progress.

These writes hold a kernfs active reference on the file.  If cgroup
removal starts in parallel, the remover sets CSS_DYING and then waits in
kernfs_drain() under cgroup_mutex for the active reference to drain. 
Continuing reclaim after the memcg is dying can therefore delay cgroup
removal and keep cgroup_mutex held for a long time.

Stop the v1 reclaim loops once the memcg is dying.  For limit resizing,
keep the existing -EBUSY semantics when the new limit could not be
installed.  For memory.force_empty, keep the existing best-effort success
semantics.

Link: https://lore.kernel.org/[email protected]
Signed-off-by: Jiayuan Chen <[email protected]>
Reported-by: Zhou Yingfu <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Jiayuan Chen <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: Barry Song <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Wei Xu <[email protected]>
Cc: Yuanchu Xie <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 mm/memcontrol-v1.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/mm/memcontrol-v1.c~memcg-v1-bail-out-reclaim-when-memcg-is-dying
+++ a/mm/memcontrol-v1.c
@@ -1805,6 +1805,10 @@ static int mem_cgroup_resize_max(struct
 		if (!ret)
 			break;
 
+		/* cgroup_rmdir() waits for us with cgroup_mutex held. */
+		if (memcg_is_dying(memcg))
+			break;
+
 		if (!drained) {
 			drain_all_stock(memcg);
 			drained = true;
@@ -1843,6 +1847,10 @@ static int mem_cgroup_force_empty(struct
 		if (signal_pending(current))
 			return -EINTR;
 
+		/* cgroup_rmdir() waits for us with cgroup_mutex held. */
+		if (memcg_is_dying(memcg))
+			break;
+
 		if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL,
 						  MEMCG_RECLAIM_MAY_SWAP, NULL))
 			nr_retries--;
_

Patches currently in -mm which might be from [email protected] are