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From:   Shakeel Butt <shakeelb@google.com>
Date:   Thu, 19 Aug 2021 13:26:55 -0700
Message-ID: <CALvZod5m3PE1vBEaW+FoiByYHGJZiDF5TR-33dGXpH7BNNcvWw@mail.gmail.com>
Subject: Re: [PATCH] mm: vmscan: consistent update to pgdeactivate and pgactivate
To:     Hao Lee <haolee.swjtu@gmail.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Linux MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Thu, Aug 19, 2021 at 9:31 AM Hao Lee <haolee.swjtu@gmail.com> wrote:
>
> After the commit 912c05720f00 ("mm: vmscan: consistent update to
> pgrefill"), pgrefill is consistent with pgscan and pgsteal. Only under
> global reclaim, are they updated at system level. Apart from that,
> pgdeactivate is often used together with pgrefill to measure the
> deactivation efficiency and pgactivate is used together with
> pgscan to measure the reclaim efficiency. It's also necessary to
> make pgdeactivate and pgactivate consistent with this rule.
>
> Signed-off-by: Hao Lee <haolee@didiglobal.com>

pgactivate and pgdeactivate are also updated in code paths other than
memory reclaim like mark_page_accessed() or madvise(COLD). Wouldn't
that impact your analysis of these metrics as well?