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References: <20210309100717.253-1-songmuchun@bytedance.com> <20210309100717.253-2-songmuchun@bytedance.com>
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From:   Shakeel Butt <shakeelb@google.com>
Date:   Thu, 11 Mar 2021 10:56:02 -0800
Message-ID: <CALvZod61mTEK2L_a9a+t10S4XWu-F+-h8SNCaG5UbC+U97v=aQ@mail.gmail.com>
Subject: Re: [PATCH v3 1/4] mm: memcontrol: introduce obj_cgroup_{un}charge_pages
To:     Muchun Song <songmuchun@bytedance.com>
Cc:     Roman Gushchin <guro@fb.com>, Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux MM <linux-mm@kvack.org>,
        Xiongchun duan <duanxiongchun@bytedance.com>
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On Tue, Mar 9, 2021 at 2:09 AM Muchun Song <songmuchun@bytedance.com> 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>

Reviewed-by: Shakeel Butt <shakeelb@google.com>