Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 24 May 2022 18:31:44 -0700
From:   Roman Gushchin <roman.gushchin@linux.dev>
To:     Vasily Averin <vvs@openvz.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>, kernel@openvz.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Shakeel Butt <shakeelb@google.com>,
        Michal =?iso-8859-1?Q?Koutn=FD?= <mkoutny@suse.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Michal Hocko <mhocko@suse.com>, cgroups@vger.kernel.org
Subject: Re: [PATCH mm v2 9/9] memcg: enable accounting for percpu allocation
 of struct rt_rq
Message-ID: <Yo2HAGmySUVABVkt@carbon>
References: <Yn6aL3cO7VdrmHHp@carbon>
 <d7094aa2-1cd0-835c-9fb7-d76003c47dad@openvz.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <d7094aa2-1cd0-835c-9fb7-d76003c47dad@openvz.org>
Precedence: bulk

On Sat, May 21, 2022 at 07:39:03PM +0300, Vasily Averin wrote:
> 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
> contianers.
> 
> Signed-off-by: Vasily Averin <vvs@openvz.org>

Acked-by: Roman Gushchin <roman.gushchin@linux.dev>