From: Andrew Morton <akpm@zip.com.au>
To: Dan Maas <dmaas@dcine.com>
Cc: Rik van Riel <riel@conectiva.com.br>,
"David S. Miller" <davem@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: Swap
Date: Tue, 20 Nov 2001 15:05:44 -0800 [thread overview]
Message-ID: <3BFAE1C8.4735C164@zip.com.au> (raw)
In-Reply-To: <Pine.LNX.4.33L.0111202019170.4079-100000@imladris.surriel.com> <03bb01c17213$887ccd30$1a01a8c0@allyourbase>
Dan Maas wrote:
>
> > Uhhhh, read his original mail. When using mmap() he had
> > problems with the VM doing bad page replacement, while
> > read() was smooth.
>
> I should add that I did experiment with madvise(MADV_SEQUENTIAL) on the
> mapping, and with madvise(MADV_WILLNEED) on pages about to be needed. These
> had no effect. What *did* help with underruns was pre-touching each page in
> a large block (120KB), before sending that block to the output device. At
> that point I thought the mmap() code was getting to be more complicated that
> it was worth so I just dropped back to read()...
There's a new system call, sys_readahead() which does what you want.
It would be nice to make the pagein code smarter though.
-
next prev parent reply other threads:[~2001-11-20 23:06 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <fa.kmf405v.j74f21@ifi.uio.no>
[not found] ` <fa.ns5ugpv.q02sbg@ifi.uio.no>
2001-11-20 21:26 ` Swap Dan Maas
2001-11-20 22:05 ` Swap Rik van Riel
2001-11-20 22:11 ` Swap David S. Miller
2001-11-20 22:19 ` Swap Rik van Riel
2001-11-20 22:34 ` Swap Dan Maas
2001-11-20 23:05 ` Andrew Morton [this message]
[not found] ` <fa.jc73ejv.1s6e80t@ifi.uio.no>
2001-11-21 1:45 ` Swap Håvard Kvålen
2001-11-21 4:23 ` Swap Andreas Dilger
2001-11-20 22:23 ` Swap Andrew Morton
2001-11-20 23:01 ` Swap David S. Miller
2001-11-20 23:35 ` Swap Rik van Riel
2001-11-20 23:40 ` Swap David S. Miller
2001-11-21 0:19 ` Swap Rik van Riel
2001-11-21 0:21 ` Swap David S. Miller
[not found] <fa.kb6ct7v.pgku0d@ifi.uio.no>
[not found] ` <fa.k8qdvcv.184ak2l@ifi.uio.no>
2001-11-20 22:46 ` Swap Dan Maas
2001-11-20 23:17 ` Swap Trond Myklebust
[not found] <fa.inl6g6v.1mmbp4@ifi.uio.no>
[not found] ` <fa.heevhav.sjs8an@ifi.uio.no>
2001-11-18 22:15 ` Swap Dan Maas
2001-11-18 22:43 ` Swap François Cami
2001-11-19 9:18 ` Swap James A Sutherland
2001-11-19 10:51 ` Swap Remco Post
2001-11-19 13:33 ` Swap James A Sutherland
2001-11-19 13:46 ` Swap Remco Post
2001-11-19 16:58 ` Swap Rik van Riel
[not found] ` <Pine.LNX.4.33L.0111191458150.1491-100000@duckman.distro.conecti va>
2001-11-19 21:13 ` Swap Alex Bligh - linux-kernel
2001-11-19 21:17 ` Swap Rik van Riel
[not found] ` <Pine.LNX.4.33L.0111191917000.1491-100000@duckman.distro.conecti va>
2001-11-19 21:52 ` Swap Alex Bligh - linux-kernel
2001-11-19 16:36 ` Swap Jesse Pollard
2001-11-20 14:51 ` Swap J.A. Magallon
2001-11-20 16:01 ` Swap Wolfgang Rohdewald
2001-11-20 16:06 ` Swap Remco Post
2001-11-20 16:12 ` Swap Nick LeRoy
2001-11-20 16:20 ` Swap Richard B. Johnson
2001-11-20 17:14 ` Swap Christopher Friesen
2001-11-20 17:40 ` Swap Richard B. Johnson
2001-11-20 18:14 ` Swap Nick LeRoy
2001-11-21 10:17 ` Swap Helge Hafting
2001-11-21 11:17 ` Swap Alan Cox
2001-11-20 23:20 ` Swap Luigi Genoni
2001-11-21 16:44 ` Swap Remco Post
2001-11-20 17:58 ` Swap Wolfgang Rohdewald
2001-11-20 21:05 ` Swap Steffen Persvold
2001-11-20 21:18 ` Swap Mike Fedyk
2001-11-20 21:33 ` Swap Nick LeRoy
2001-11-20 21:44 ` Swap Mike Fedyk
2001-11-20 22:00 ` Swap Nick LeRoy
2001-11-21 16:53 ` Swap Remco Post
2001-11-20 21:43 ` Swap Richard B. Johnson
2001-11-20 21:19 ` Swap Nick LeRoy
2001-11-21 16:48 ` Swap Remco Post
2001-11-20 20:58 ` Swap Mike Fedyk
2001-11-19 10:03 ` Swap Tim Connors
2001-11-19 10:16 ` Swap Dan Maas
2001-11-18 21:12 Swap war
2001-11-18 21:25 ` Swap James A Sutherland
2001-11-18 21:28 ` Swap war
2001-11-18 21:42 ` Swap François Cami
2001-11-18 21:45 ` Swap war
2001-11-18 23:03 ` Swap Erik Gustavsson
2001-11-19 18:12 ` Swap Eric W. Biederman
2001-11-19 18:43 ` Swap Rik van Riel
2001-11-20 2:49 ` Swap Eric W. Biederman
2001-11-20 3:33 ` Swap Ryan Cumming
2001-11-20 11:43 ` Swap Rik van Riel
2001-11-20 11:41 ` Swap Rik van Riel
2001-11-19 19:12 ` Swap James A Sutherland
2001-11-20 2:47 ` Swap Eric W. Biederman
2001-11-20 9:16 ` Swap James A Sutherland
2001-11-18 22:05 ` Swap J.A. Magallon
2001-11-18 22:21 ` Swap François Cami
2001-11-18 22:36 ` Swap Charles Marslett
2001-11-18 22:54 ` Swap J.A. Magallon
2001-11-18 23:36 ` Swap Bernd Eckenfels
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