From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264501AbTLQSxy (ORCPT ); Wed, 17 Dec 2003 13:53:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264504AbTLQSxy (ORCPT ); Wed, 17 Dec 2003 13:53:54 -0500 Received: from nat-pool-bos.redhat.com ([66.187.230.200]:47440 "EHLO chimarrao.boston.redhat.com") by vger.kernel.org with ESMTP id S264501AbTLQSxw (ORCPT ); Wed, 17 Dec 2003 13:53:52 -0500 Date: Wed, 17 Dec 2003 13:53:28 -0500 (EST) From: Rik van Riel X-X-Sender: riel@chimarrao.boston.redhat.com To: Roger Luethi cc: Andrew Morton , Andrea Arcangeli , , , , , Subject: Re: 2.6.0-test9 - poor swap performance on low end machines In-Reply-To: <20031216112307.GA5041@k3.hellgate.ch> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 16 Dec 2003, Roger Luethi wrote: > One potential problem with the benchmarks is that my test box has > just one bar with 256 MB RAM. The kbuild and efax tests were run with > mem=64M and mem=32M, respectively. If the difference between mem=32M OK, I found another difference with 2.4. Try "echo 256 > /proc/sys/vm/min_free_kbytes", I think that should give the same free watermarks that 2.4 has. Using 1MB as the min free watermark for lowmem is bound to result in more free (and less used) memory on systems with less than 128 MB RAM ... significantly so on smaller systems. The fact that ZONE_HIGHMEM and ZONE_NORMAL are recycled at very different rates could also be of influence on some performance tests... -- "Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." - Brian W. Kernighan