From: Andrew Morton <akpm@zip.com.au>
To: Roy Sigurd Karlsbakk <roy@karlsbakk.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: /proc/sys/vm/(max|min)-readahead effect????
Date: Wed, 05 Dec 2001 12:13:34 -0800 [thread overview]
Message-ID: <3C0E7FEE.2770EDF4@zip.com.au> (raw)
In-Reply-To: <Pine.LNX.4.30.0112051713200.2297-100000@mustard.heime.net>
Roy Sigurd Karlsbakk wrote:
>
> hi all
>
> I've just upgraded to 2.4.16 to get /proc/sys/vm/(max|min)-readahead
> available. I've got this idea...
>
> If lots of files (some hundered) are read simultaously, I waste all the
> i/o time in seeks. However, if I increase the readahead, it'll read more
> data at a time, and end up with seeking a lot less.
>
> The harddrive I'm testing this with, is a cheap 20G IDE drive.
/proc/sys/vm/*-readhead is a no-op for IDE. It doesn't do
anything. You must use
echo file_readahead:100 > /proc/ide/ide0/hda/settings
to set the readhead to 100 pages (409600 bytes).
-
next prev parent reply other threads:[~2001-12-05 20:16 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-12-05 16:21 /proc/sys/vm/(max|min)-readahead effect???? Roy Sigurd Karlsbakk
2001-12-05 16:51 ` Marcelo Tosatti
2001-12-05 18:09 ` Roy Sigurd Karlsbakk
2001-12-05 16:58 ` Marcelo Tosatti
2001-12-05 18:20 ` Roy Sigurd Karlsbakk
2001-12-05 19:43 ` James Stevenson
2001-12-05 20:06 ` Roy Sigurd Karlsbakk
2001-12-05 20:53 ` James Stevenson
2001-12-06 11:45 ` Roy Sigurd Karlsbakk
2001-12-06 18:44 ` Bernd Eckenfels
2001-12-05 18:22 ` Rik van Riel
2001-12-05 18:27 ` Roy Sigurd Karlsbakk
2001-12-06 10:09 ` Martin Dalecki
2001-12-05 20:13 ` Andrew Morton [this message]
2001-12-05 20:53 ` Roger Larsson
2001-12-06 11:31 ` Roy Sigurd Karlsbakk
2001-12-06 18:46 ` Bernd Eckenfels
2001-12-07 11:25 ` Roy Sigurd Karlsbakk
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