From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 23 May 2002 18:28:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 23 May 2002 18:28:48 -0400 Received: from twilight.ucw.cz ([195.39.74.230]:27042 "EHLO twilight.ucw.cz") by vger.kernel.org with ESMTP id ; Thu, 23 May 2002 18:28:46 -0400 Date: Fri, 24 May 2002 00:28:29 +0200 From: Vojtech Pavlik To: Chris , linux-kernel@vger.kernel.org Subject: Re: It hurts when I shoot myself in the foot Message-ID: <20020524002829.A27005@ucw.cz> In-Reply-To: <200205221615.g4MGFCH30271@directcommunications.net> <20020523034821.GK458@turbolinux.com> <20020523044933.GB4006@matchmail.com> <20020523054219.GL458@turbolinux.com> <20020523173305.GC4006@matchmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 23, 2002 at 10:33:05AM -0700, Mike Fedyk wrote: > On Wed, May 22, 2002 at 11:42:19PM -0600, Andreas Dilger wrote: > > On May 22, 2002 21:49 -0700, Mike Fedyk wrote: > > > On Wed, May 22, 2002 at 09:48:21PM -0600, Andreas Dilger wrote: > > > > There was a kernel patch posted about 5 or so months ago which would > > > > "handle" this setup (CPUs with the same clock speed, but different > > > > multipliers). Alan Cox said it probably was a bad idea, so it wouldn't > > > > go into the kernel, but the patch may still be usable. > > > > > > > > This is sometimes called "asymmetric multiprocessing", and the thread > > > > is at http://marc.theaimsgroup.com/?l=linux-kernel&m=98519070331478&w=4 > > > > > > I thought asymmetric multiprocessing would support CPUs with different > > > speeds. ie, 400 & 450mhz. How would you get different multipliers and same > > > Mhz when the CPUs are on the same FSB(ignoring AMD SMP where each processor > > > has an exclusive FSB, and this might be possible)? > > > > That was what I was trying to say: same FSB speed * different multipliers > > = different CPU MHZ, like what the original poster is asking about. > > I don't think it is possible to configure a motherboard to have different > > FSB speeds for two processors. > > > > Me neither, but it seems theoretically possible. It is not, they are both on the same FSB, at least in Pentium II/III case. -- Vojtech Pavlik SuSE Labs