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Message-ID: <a17be77f-dc3b-d69a-16e2-f7309959c525@openvz.org>
Date:   Fri, 13 May 2022 18:52:12 +0300
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From:   Vasily Averin <vvs@openvz.org>
Subject: [PATCH 3/4] memcg: enable accounting for struct cgroup
To:     Roman Gushchin <roman.gushchin@linux.dev>,
        Shakeel Butt <shakeelb@google.com>,
        =?UTF-8?Q?Michal_Koutn=c3=bd?= <mkoutny@suse.com>
Cc:     kernel@openvz.org, linux-kernel@vger.kernel.org,
        Vlastimil Babka <vbabka@suse.cz>,
        Michal Hocko <mhocko@suse.com>, cgroups@vger.kernel.org
References: <Ynv7+VG+T2y9rpdk@carbon>
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In-Reply-To: <Ynv7+VG+T2y9rpdk@carbon>
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Creating each new cgroup allocates 4Kb for struct cgroup. This is the
largest memory allocation in this scenario and is epecially important
for small VMs with 1-2 CPUs.

Accounting of this memory helps to avoid misuse inside memcg-limited
containers.

Signed-off-by: Vasily Averin <vvs@openvz.org>
---
 kernel/cgroup/cgroup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index adb820e98f24..7595127c5b3a 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -5353,7 +5353,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent, const char *name,
 
 	/* allocate the cgroup and its ID, 0 is reserved for the root */
 	cgrp = kzalloc(struct_size(cgrp, ancestor_ids, (level + 1)),
-		       GFP_KERNEL);
+		       GFP_KERNEL_ACCOUNT);
 	if (!cgrp)
 		return ERR_PTR(-ENOMEM);
 
-- 
2.31.1