Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261304AbTI3JvD (ORCPT ); Tue, 30 Sep 2003 05:51:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261309AbTI3JvD (ORCPT ); Tue, 30 Sep 2003 05:51:03 -0400 Received: from ns.suse.de ([195.135.220.2]:43716 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S261304AbTI3JvB (ORCPT ); Tue, 30 Sep 2003 05:51:01 -0400 To: Gabriel Paubert Cc: jamie@shareable.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Athlon Prefetch workaround for 2.6.0test6 References: <20030929125629.GA1746@averell.suse.lists.linux.kernel> <20030929170323.GC21798@mail.jlokier.co.uk.suse.lists.linux.kernel> <20030929174910.GA90905@colin2.muc.de.suse.lists.linux.kernel> <20030929200820.GA23444@mail.jlokier.co.uk.suse.lists.linux.kernel> <20030930093556.GB12970@iram.es.suse.lists.linux.kernel> From: Andi Kleen Date: 30 Sep 2003 11:50:53 +0200 In-Reply-To: <20030930093556.GB12970@iram.es.suse.lists.linux.kernel> Message-ID: Lines: 15 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 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 Gabriel Paubert writes: > On Mon, Sep 29, 2003 at 09:08:20PM +0100, Jamie Lokier wrote: > > Btw, you assume that regs->xcs is a valid segment value. I think that > > the upper 16 bits are not guaranteed to be zero in general on the > > IA32, although they clearly are zero for the majority of IA-32 chips. > > Are they guaranteed to be zero on AMD's processors? > > At least for pushes of segment registers a 486 decrements > the stack pointer by 4 but only writes the 2 least significant > bytes, leaving garbage in the upper half. The code only runs on newer AMD CPUs (K7/K8) -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/