linux-kernel - [PATCH mm v3 9/9] memcg: enable accounting for perpu allocation of struct rt

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <a1fcdab2-a208-0fad-3f4e-233317ab828f@openvz.org>
Date:   Mon, 30 May 2022 14:27:07 +0300
From:   Vasily Averin <vvs@...nvz.org>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     kernel@...nvz.org, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, Shakeel Butt <shakeelb@...gle.com>,
        Roman Gushchin <roman.gushchin@...ux.dev>,
        Michal Koutný <mkoutny@...e.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Michal Hocko <mhocko@...e.com>,
        Muchun Song <songmuchun@...edance.com>, cgroups@...r.kernel.org
Subject: [PATCH mm v3 9/9] memcg: enable accounting for perpu allocation of
 struct rt_rq

If enabled in config, alloc_rt_sched_group() is called for each new
cpu cgroup and allocates a huge (~1700 bytes) percpu struct rt_rq.
This significantly exceeds the size of the percpu allocation in the
common part of cgroup creation.

Memory allocated during new cpu cgroup creation
(with enabled RT_GROUP_SCHED):
common part:    ~11Kb   +   318 bytes percpu
cpu cgroup:     ~2.5Kb  + ~2800 bytes percpu

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

Signed-off-by: Vasily Averin <vvs@...nvz.org>
Acked-by: Shakeel Butt <shakeelb@...gle.com>
Acked-by: Roman Gushchin <roman.gushchin@...ux.dev>
---
 kernel/sched/rt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 8c9ed9664840..44a8fc096e33 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -256,7 +256,7 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
 
 	for_each_possible_cpu(i) {
 		rt_rq = kzalloc_node(sizeof(struct rt_rq),
-				     GFP_KERNEL, cpu_to_node(i));
+				     GFP_KERNEL_ACCOUNT, cpu_to_node(i));
 		if (!rt_rq)
 			goto err;
 
-- 
2.36.1