From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965088AbXGLA2z (ORCPT ); Wed, 11 Jul 2007 20:28:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964974AbXGLASa (ORCPT ); Wed, 11 Jul 2007 20:18:30 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:40968 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964950AbXGLASZ (ORCPT ); Wed, 11 Jul 2007 20:18:25 -0400 Date: Thu, 12 Jul 2007 02:18:07 +0200 From: Ingo Molnar To: Andi Kleen Cc: Linus Torvalds , Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org, Arjan van de Ven , Chris Wright Subject: Re: x86 status was Re: -mm merge plans for 2.6.23 Message-ID: <20070712001807.GB1946@elte.hu> References: <20070711174252.GA16793@elte.hu> <1184191488.12353.160.camel@chaos> <1184194219.12353.170.camel@chaos> <20070711233618.GD25510@one.firstfloor.org> <20070711235852.GA625@elte.hu> <20070712000720.GA26585@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070712000720.GA26585@one.firstfloor.org> User-Agent: Mutt/1.5.14 (2007-02-12) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7-deb -1.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Andi Kleen wrote: > > i dont think "clean, modern x86 code" will ever happen - x86_64 has > > and is going to have the exact same type of crap. And i'll say a > > weird thing > > Yes, but it will be new crap, but no old crap anymore. > > If you always pile the new crap on the old crap at some point the > whole thing might fall over. 64bit was intended as a fresh start. I think there's no such thing as a fresh start for a diverse architecture - the ia64 failure has proven that. x86_64 CPUs still do A20 emulation today (!). We still have people running industrial boards on real i386 DX CPUs, with the latest upstream kernel. 15 years ago an i386 DX was already quite obsolete. 32-bit is not going to go away in our lifetime, and we'll want to support it in a first-grade way. We better realize that prospect and have it right before our eyes in a single tree wherever it makes sense to share code - i'm certainly not talking about sharing mtrr/centaur.c or k8.c. (and i'm not necessarily suggesting to share io_apic.c either - although it's certainly borderline.) Ingo