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Date:   Fri, 10 Jun 2022 16:01:49 -0700
From:   Roman Gushchin <roman.gushchin@linux.dev>
To:     Muchun Song <songmuchun@bytedance.com>
Cc:     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 01/11] mm: memcontrol: remove dead code and comments
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References: <20220530074919.46352-1-songmuchun@bytedance.com>
 <20220530074919.46352-2-songmuchun@bytedance.com>
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On Mon, May 30, 2022 at 03:49:09PM +0800, Muchun Song wrote:
> Since no-hierarchy mode is deprecated after
> 
>   commit bef8620cd8e0 ("mm: memcg: deprecate the non-hierarchical mode")
> 
> so parent_mem_cgroup() cannot return a NULL except root memcg, however, root
> memcg cannot be offline, so it is safe to drop the check of returned value
> of parent_mem_cgroup().  Remove those dead code.
> 
> The comments in memcg_offline_kmem() above memcg_reparent_list_lrus() are
> out of date since
> 
>   commit 5abc1e37afa0 ("mm: list_lru: allocate list_lru_one only when needed")
> 
> There is no ordering requirement between memcg_reparent_list_lrus() and
> memcg_reparent_objcgs(), so remove those outdated comments.
> 
> Signed-off-by: Muchun Song <songmuchun@bytedance.com>

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

Nice cleanup!