From: Theodore Ts'o <tytso@mit.edu>
Subject: Re: page eviction from the buddy cache
Date: Tue, 23 Apr 2013 08:27:08 -0400
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Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com>,
	Will Huck <will.huckk@gmail.com>, Hugh Dickins <hughd@google.com>,
	Andrew Perepechko <anserper@ya.ru>, linux-ext4@vger.kernel.org,
	akpm@linux-foundation.org, linux-mm@kvack.org, mgorman@suse.de
To: Bernd Schubert <bernd.schubert@fastmail.fm>
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On Tue, Apr 23, 2013 at 02:02:37PM +0200, Bernd Schubert wrote:
> 
> I just thought we can (mis)use that flag and and add another
> information to the page that it holds meta data. The mm system then
> could use that flag and evict those pages with a lower priority
> compared to other pages.

Well, the flag I added was to the buffer_head, not to the page, and my
understanding is that the mm folks are very hesitant to add new page
flags, since they are bumping up against the 32 bit limit (on the i386
platform), and they are trying to keep the struct page structure trim
and svelte.  :-)

						- Ted

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