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Date: Fri, 9 Aug 2013 15:53:09 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-mm@kvack.org, Andi Kleen <andi@firstfloor.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Greg Thelen <gthelen@google.com>,
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        Roman Gushchin <klamm@yandex-team.ru>,
        Ozgun Erdogan <ozgun@citusdata.com>, Metin Doslu <metin@citusdata.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [patch 0/9] mm: thrash detection-based file cache sizing v3
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On Tue,  6 Aug 2013 18:44:01 -0400 Johannes Weiner <hannes@cmpxchg.org> wrote:

> This series solves the problem by maintaining a history of pages
> evicted from the inactive list, enabling the VM to tell streaming IO
> from thrashing and rebalance the page cache lists when appropriate.

Looks nice. The lack of testing results is conspicuous ;)

It only really solves the problem in the case where

	size-of-inactive-list < size-of-working-set < size-of-total-memory

yes?  In fact less than that, because the active list presumably
doesn't get shrunk to zero (how far *can* it go?).  I wonder how many
workloads fit into those constraints in the real world.