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Date: Fri, 2 Nov 2001 10:24:21 +0100
From: Robert Varga <nite@hq.alert.sk>
To: linux-kernel@vger.kernel.org
Subject: Re: writing a plugin for reiserfs compression
Message-ID: <20011102102421.A25221@hq.alert.sk>
In-Reply-To: <3BE1C07D.5080205@antefacto.com> <Pine.LNX.4.30.0111012242060.3245-100000@mustard.heime.net>
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In-Reply-To: <Pine.LNX.4.30.0111012242060.3245-100000@mustard.heime.net>; from roy@karlsbakk.net on Thu, Nov 01, 2001 at 10:43:37PM +0100
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On Thu, Nov 01, 2001 at 10:43:37PM +0100, Roy Sigurd Karlsbakk wrote:
> > Note this transparent ext2 compression patch is only available for 2.2
>=20
> Would it be hard to port to 2.4?

AFAIK kinda yes. It relies on IO going through block buffer cache:
Buffer cache contains the compressed data, while the page cache has it all =
decompressed.
This avoids excessive (de)compression (you need to compress data only when =
commiting page
to disk).

With 2.4 Ext2 moved (almost?) entirely out of buffer cache, you'll need to
create your own IO buffers. This is the only solution I came up with. Is th=
ere some
other approach how to cope with this problem ?

--=20
Kind regards,
Robert Varga
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n@hq.sk                                          http://hq.sk/~nite/gpgkey.=
txt
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