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Subject: Re: [PATCH] mm/memcontrol: update lruvec counters in
 mem_cgroup_move_account
To:     Johannes Weiner <hannes@cmpxchg.org>
Cc:     linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
        Michal Hocko <mhocko@kernel.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>
References: <157112699975.7360.1062614888388489788.stgit@buzz>
 <20191015135348.GA139269@cmpxchg.org>
From:   Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Message-ID: <89171a94-8b6f-e949-0078-10fa8fd26dfc@yandex-team.ru>
Date:   Tue, 15 Oct 2019 17:04:44 +0300
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On 15/10/2019 16.53, Johannes Weiner wrote:
> On Tue, Oct 15, 2019 at 11:09:59AM +0300, Konstantin Khlebnikov wrote:
>> Mapped, dirty and writeback pages are also counted in per-lruvec stats.
>> These counters needs update when page is moved between cgroups.
>>
>> Fixes: 00f3ca2c2d66 ("mm: memcontrol: per-lruvec stats infrastructure")
>> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
> 
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> 
> Please mention in the changelog that currently is nobody *consuming*
> the lruvec versions of these counters and that there is no
> user-visible effect. Thanks
> 

Maybe just kill all these per-lruvec counters?
I see only one user which have no alternative data source: WORKINGSET_ACTIVATE.

This will save some memory: 32 * sizeof(long) * nr_nodes * nr_cpus bytes