From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264526AbTLQTvd (ORCPT ); Wed, 17 Dec 2003 14:51:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264534AbTLQTvd (ORCPT ); Wed, 17 Dec 2003 14:51:33 -0500 Received: from nat-pool-bos.redhat.com ([66.187.230.200]:48985 "EHLO chimarrao.boston.redhat.com") by vger.kernel.org with ESMTP id S264526AbTLQTva (ORCPT ); Wed, 17 Dec 2003 14:51:30 -0500 Date: Wed, 17 Dec 2003 14:51:05 -0500 (EST) From: Rik van Riel X-X-Sender: riel@chimarrao.boston.redhat.com To: William Lee Irwin III cc: Roger Luethi , Andrew Morton , Andrea Arcangeli , , , , Subject: Re: 2.6.0-test9 - poor swap performance on low end machines In-Reply-To: <20031217192742.GB22443@holomorphy.com> 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 Wed, 17 Dec 2003, William Lee Irwin III wrote: > Limited sets of configurations may have left holes in the testing. > Upper zones much larger than lower zones basically want the things > to be unequal. It probably wants the replacement load spread > proportionally in general or some such nonsense. Yeah. In some configurations 2.4-rmap takes care of this automagically since part of the replacement isn't as pressure driven as in 2.4 mainline and 2.6, ie. some of the aging is done independantly of allocation pressure. Still, inter-zone balancing is HARD to get right. I'm currently trying to absorb all of the 2.6 VM balancing into my mind (*sound effects of brain turning to slush*) to find any possible imbalances. Some of the test results I have seen make me very suspicious... -- "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