From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 18 May 2001 19:01:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 18 May 2001 19:01:27 -0400 Received: from nat-pool-meridian.redhat.com ([199.183.24.200]:61046 "EHLO devserv.devel.redhat.com") by vger.kernel.org with ESMTP id ; Fri, 18 May 2001 19:01:19 -0400 Date: Fri, 18 May 2001 23:58:52 +0100 From: "Stephen C. Tweedie" To: Rik van Riel Cc: Mike Galbraith , Ingo Oeser , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: Linux 2.4.4-ac10 Message-ID: <20010518235852.R8080@redhat.com> In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from riel@conectiva.com.br on Fri, May 18, 2001 at 07:44:39PM -0300 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Fri, May 18, 2001 at 07:44:39PM -0300, Rik van Riel wrote: > This is the core of why we cannot (IMHO) have a discussion > of whether a patch introducing new VM tunables can go in: > there is no clear overview of exactly what would need to be > tunable and how it would help. It's worse than that. The workload on most typical systems is not static. The VM *must* be able to cope with dynamic workloads. You might twiddle all the knobs on your system to make your database run faster, but end up in such a situation that the next time a mail flood arrives for sendmail, the whole box locks up because the VM can no longer adapt. That's the main problem with static parameters. The problem you are trying to solve is fundamentally dynamic in most cases (which is also why magic numbers tend to suck in the VM.) Cheers, Stephen