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Message-ID: <68433856-6b7b-2e9e-6e86-77293da7453b@bytedance.com>
Date:   Sat, 4 Jun 2022 09:24:38 +0800
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Subject: Re: [PATCH] mm: memcontrol: separate {pgscan,pgsteal}_{kswapd,direct}
 items in memory.stat of cgroup v2
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To:     Shakeel Butt <shakeelb@google.com>
Cc:     Michal Hocko <mhocko@kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Muchun Song <songmuchun@bytedance.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Linux MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>
References: <20220603070423.10025-1-zhengqi.arch@bytedance.com>
 <CALvZod6s8ss0Doe9y+X=3ZHvw0Ove9Lw3MdfKekXr0gVnJwA4w@mail.gmail.com>
From:   Qi Zheng <zhengqi.arch@bytedance.com>
In-Reply-To: <CALvZod6s8ss0Doe9y+X=3ZHvw0Ove9Lw3MdfKekXr0gVnJwA4w@mail.gmail.com>
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On 2022/6/4 8:47 AM, Shakeel Butt wrote:
> On Fri, Jun 3, 2022 at 12:06 AM Qi Zheng <zhengqi.arch@bytedance.com> wrote:
>>
> [...]
>>
>> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
>> index 176298f2f4de..0b9ca7e7df34 100644
>> --- a/Documentation/admin-guide/cgroup-v2.rst
>> +++ b/Documentation/admin-guide/cgroup-v2.rst
>> @@ -1442,11 +1442,17 @@ PAGE_SIZE multiple when read back.
>>            pgrefill (npn)
>>                  Amount of scanned pages (in an active LRU list)
>>
>> -         pgscan (npn)
>> -               Amount of scanned pages (in an inactive LRU list)
>> +         pgscan_kswapd (npn)
>> +               Amount of scanned pages by kswapd (in an inactive LRU list)
>>
>> -         pgsteal (npn)
>> -               Amount of reclaimed pages
>> +         pgscan_direct (npn)
>> +               Amount of scanned pages directly  (in an inactive LRU list)
>> +
>> +         pgsteal_kswapd (npn)
>> +               Amount of reclaimed pages by kswapd
>> +
>> +         pgsteal_direct (npn)
>> +               Amount of reclaimed pages directly
> 
> No objection to adding new fields but removing 'pgsteal' and 'pgscan'
> from the user visible API might break some applications.

Oh, got it. So do we need to keep pgscan and pgsteal fields? If it is, I
can add it back in patch v2.

Thanks,
Qi