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Date:   Thu, 11 Mar 2021 07:30:53 -0500
From:   Johannes Weiner <hannes@cmpxchg.org>
To:     Muchun Song <songmuchun@bytedance.com>
Cc:     guro@fb.com, mhocko@kernel.org, akpm@linux-foundation.org,
        shakeelb@google.com, vdavydov.dev@gmail.com,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        duanxiongchun@bytedance.com
Subject: Re: [PATCH v3 1/4] mm: memcontrol: introduce
 obj_cgroup_{un}charge_pages
Message-ID: <YEoNfYvbMHw4ifyc@cmpxchg.org>
References: <20210309100717.253-1-songmuchun@bytedance.com>
 <20210309100717.253-2-songmuchun@bytedance.com>
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On Tue, Mar 09, 2021 at 06:07:14PM +0800, Muchun Song wrote:
> We know that the unit of slab object charging is bytes, the unit of
> kmem page charging is PAGE_SIZE. If we want to reuse obj_cgroup APIs
> to charge the kmem pages, we should pass PAGE_SIZE (as third parameter)
> to obj_cgroup_charge(). Because the size is already PAGE_SIZE, we can
> skip touch the objcg stock. And obj_cgroup_{un}charge_pages() are
> introduced to charge in units of page level.
> 
> In the later patch, we also can reuse those two helpers to charge or
> uncharge a number of kernel pages to a object cgroup. This is just
> a code movement without any functional changes.
> 
> Signed-off-by: Muchun Song <songmuchun@bytedance.com>
> Acked-by: Roman Gushchin <guro@fb.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>