Date: Wed, 12 Oct 2005 11:03:02 -0700
From: Andy Isaacson <adi@hexapodia.org>
To: Pavel Machek <pavel@suse.cz>
Cc: Felix Oxley <lkml@oxley.org>, OBATA Noboru <noboru.obata.ar@hitachi.com>,
       hyoshiok@miraclelinux.com, linux-kernel@vger.kernel.org
Subject: Re: Linux Kernel Dump Summit 2005
Message-ID: <20051012180302.GA30732@hexapodia.org>
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On Wed, Oct 12, 2005 at 12:07:31PM +0200, Pavel Machek wrote:
> On St 12-10-05 10:56:46, Felix Oxley wrote:
> > > See Jamie Lokier's description how to *never* slow down. 
> > Sorry, where is this?
> 
> Somewhere on the lkml, *long* ago. Basically idea is to have one
> thread doing writing to disk, and second thread doing compression. If
> no compressed pages are available, just write uncompressed ones. That
> way compression can only speed things up.

That's Message-ID: <20040327144945.GG21884@mail.shareable.org>, dated
2004-03-27 14:49:45.  (Oh look, sendmail encodes the date in the
Message-ID in exactly that format.)

This technique only works for DMA-capable IO -- PIO will make it suck --
but attempting to dump 32GB via PIO would be insane anyways, so...

-andy
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