+ memcg-notify-about-global-mem_cgroup_id-space-depletion.patch added to mm-unstable branch

+ memcg-notify-about-global-mem_cgroup_id-space-depletion.patch added to mm-unstable branch

[Andrew Morton]

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The patch titled
     Subject: memcg: notify about global mem_cgroup_id space depletion
has been added to the -mm mm-unstable branch.  Its filename is
     memcg-notify-about-global-mem_cgroup_id-space-depletion.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/memcg-notify-about-global-mem_cgroup_id-space-depletion.patch

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

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------------------------------------------------------
From: Vasily Averin <vvs@openvz.org>
Subject: memcg: notify about global mem_cgroup_id space depletion
Date: Mon, 27 Jun 2022 05:11:26 +0300

Currently, the host owner is not informed about the exhaustion of the
global mem_cgroup_id space.  When this happens, systemd cannot start a new
service and receives a unique -ENOSPC error code.  However, this can
happen inside this container, persist in the log file of the local
container, and may not be noticed by the host owner if he did not try to
start any new services.

Link: https://lkml.kernel.org/r/97bed1fd-f230-c2ea-1cb6-8230825a9a64@openvz.org
Signed-off-by: Vasily Averin <vvs@openvz.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memcontrol.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/mm/memcontrol.c~memcg-notify-about-global-mem_cgroup_id-space-depletion
+++ a/mm/memcontrol.c
@@ -5286,6 +5286,8 @@ static struct mem_cgroup *mem_cgroup_all
 				 1, MEM_CGROUP_ID_MAX + 1, GFP_KERNEL);
 	if (memcg->id.id < 0) {
 		error = memcg->id.id;
+		if (error == -ENOSPC)
+			pr_notice_ratelimited("mem_cgroup_id space is exhausted\n");
 		goto fail;
 	}
 
_

Patches currently in -mm which might be from vvs@openvz.org are

memcg-notify-about-global-mem_cgroup_id-space-depletion.patch