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Date:   Thu, 20 Jun 2019 09:08:54 +0200
From:   Michal Hocko <mhocko@kernel.org>
To:     Minchan Kim <minchan@kernel.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        linux-mm <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>, linux-api@vger.kernel.org,
        Johannes Weiner <hannes@cmpxchg.org>,
        Tim Murray <timmurray@google.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Suren Baghdasaryan <surenb@google.com>,
        Daniel Colascione <dancol@google.com>,
        Shakeel Butt <shakeelb@google.com>,
        Sonny Rao <sonnyrao@google.com>,
        Brian Geffon <bgeffon@google.com>, jannh@google.com,
        oleg@redhat.com, christian@brauner.io, oleksandr@redhat.com,
        hdanton@sina.com, lizeb@google.com
Subject: Re: [PATCH v2 1/5] mm: introduce MADV_COLD
Message-ID: <20190620070854.GC12083@dhcp22.suse.cz>
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On Thu 20-06-19 09:06:51, Minchan Kim wrote:
> On Wed, Jun 19, 2019 at 02:56:12PM +0200, Michal Hocko wrote:
[...]
> > Why cannot we reuse a large part of that code and differ essentially on
> > the reclaim target check and action? Have you considered to consolidate
> > the code to share as much as possible? Maybe that is easier said than
> > done because the devil is always in details...
> 
> Yub, it was not pretty when I tried. Please see last patch in this
> patchset.

That is bad because this code is quite subtle - especially the THP part
of it. I will be staring at the code some more. Maybe some
simplification pops out.

-- 
Michal Hocko
SUSE Labs