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Date:   Thu, 2 Jun 2022 18:48:41 +0800
From:   Muchun Song <songmuchun@bytedance.com>
To:     Roman Gushchin <roman.gushchin@linux.dev>
Cc:     Michal =?iso-8859-1?Q?Koutn=FD?= <mkoutny@suse.com>,
        hannes@cmpxchg.org, mhocko@kernel.org, shakeelb@google.com,
        akpm@linux-foundation.org, cgroups@vger.kernel.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        duanxiongchun@bytedance.com, longman@redhat.com
Subject: Re: [PATCH v5 03/11] mm: memcontrol: prepare objcg API for non-kmem
 usage
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On Wed, Jun 01, 2022 at 11:33:46AM -0700, Roman Gushchin wrote:
> On Wed, Jun 01, 2022 at 07:34:34PM +0200, Michal Koutny wrote:
> > Hello.
> > 
> > On Mon, May 30, 2022 at 03:49:11PM +0800, Muchun Song <songmuchun@bytedance.com> wrote:
> > > So we also allocate an object cgroup for the root_mem_cgroup.
> > 
> > This change made me wary that this patch also kmem charging in the
> > root_mem_cgroup. Fortunately, get_obj_cgroup_from_current won't return
> > this objcg so all is fine.
> 
> Yes, I had the same experience here :)
>

Sorry for the confusing.
 
> Overall I feel like the handling of the root memcg and objcg are begging
> for a cleanup, but it's really far from being trivial.
> 
> Maybe starting with documenting how it works now is a good idea...
> 

You mean add more comments into the commit log to explain the
usage of root memcg and root objcg?

Thanks.