From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 6 Jun 2001 04:23:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 6 Jun 2001 04:23:28 -0400 Received: from AMontpellier-201-1-3-224.abo.wanadoo.fr ([193.252.1.224]:10489 "EHLO microsoft.com") by vger.kernel.org with ESMTP id ; Wed, 6 Jun 2001 04:23:22 -0400 Subject: Re: Break 2.4 VM in five easy steps From: Xavier Bestel To: Derek Glidden Cc: Andrew Morton , Jeffrey "W." Baker , linux-kernel@vger.kernel.org In-Reply-To: <20010605231908.A10520@illusionary.com> In-Reply-To: <3B1D5ADE.7FA50CD0@illusionary.com> <3B1D927E.1B2EBE76@uow.edu.au> <20010605231908.A10520@illusionary.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Mailer: Evolution/0.10 (Preview Release) Date: 06 Jun 2001 10:19:30 +0200 Message-Id: <991815578.30689.1.camel@nomade> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 05 Jun 2001 23:19:08 -0400, Derek Glidden wrote: > On Wed, Jun 06, 2001 at 12:16:30PM +1000, Andrew Morton wrote: > > "Jeffrey W. Baker" wrote: > > > > > > Because the 2.4 VM is so broken, and > > > because my machines are frequently deeply swapped, > > > > The swapoff algorithms in 2.2 and 2.4 are basically identical. > > The problem *appears* worse in 2.4 because it uses lots > > more swap. > > I disagree with the terminology you're using. It *is* worse in 2.4, > period. If it only *appears* worse, then if I encounter a situation > where a 2.2 box has utilized as much swap as a 2.4 box, I should see the > same results. Yet this happens not to be the case. Did you try to put twice as much swap as you have RAM ? (e.g. add a 512M swapfile to your box) This is what Linus recommended for 2.4 (swap = 2 * RAM), saying that anything less won't do any good: 2.4 overallocates swap even if it doesn't use it all. So in your case you just have enough swap to map your RAM, and nothing to really swap your apps. Xav