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Date:   Thu, 2 Apr 2020 08:27:17 +0200
From:   Michal Hocko <mhocko@kernel.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     "Huang, Ying" <ying.huang@intel.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrea Arcangeli <aarcange@redhat.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Zi Yan <ziy@nvidia.com>, Vlastimil Babka <vbabka@suse.cz>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
        =?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>,
        Yang Shi <yang.shi@linux.alibaba.com>
Subject: Re: [PATCH] /proc/PID/smaps: Add PMD migration entry parsing
Message-ID: <20200402062717.GB22681@dhcp22.suse.cz>
References: <20200331085604.1260162-1-ying.huang@intel.com>
 <20200401160432.855bba5b210c7b4bbf6c56ef@linux-foundation.org>
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On Wed 01-04-20 16:04:32, Andrew Morton wrote:
> On Tue, 31 Mar 2020 16:56:04 +0800 "Huang, Ying" <ying.huang@intel.com> wrote:
> 
> > From: Huang Ying <ying.huang@intel.com>
> > 
> > Now, when read /proc/PID/smaps, the PMD migration entry in page table is simply
> > ignored.  To improve the accuracy of /proc/PID/smaps, its parsing and processing
> > is added.
> 
> It would be helpful to show the before-and-after output in the changelog.

Migration entries are ephemeral. Is this observable in practice? I
suspect this is just primarily motivated by reading the code more than
hitting the actual problem.
-- 
Michal Hocko
SUSE Labs