From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261214AbTIKOPZ (ORCPT ); Thu, 11 Sep 2003 10:15:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261221AbTIKOPZ (ORCPT ); Thu, 11 Sep 2003 10:15:25 -0400 Received: from pc1-cwma1-5-cust4.swan.cable.ntl.com ([80.5.120.4]:32145 "EHLO dhcp23.swansea.linux.org.uk") by vger.kernel.org with ESMTP id S261214AbTIKOPW (ORCPT ); Thu, 11 Sep 2003 10:15:22 -0400 Subject: Re: [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata From: Alan Cox To: Linus Torvalds Cc: Andi Kleen , richard.brunner@amd.com, Linux Kernel Mailing List , akpm@osdl.org In-Reply-To: References: Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1063289641.2967.3.camel@dhcp23.swansea.linux.org.uk> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.4 (1.4.4-5) Date: Thu, 11 Sep 2003 15:14:02 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Iau, 2003-09-11 at 14:54, Linus Torvalds wrote: > This patch is fragile and looks pointless. > > What's wrong with the current status quo that just says "Athlon prefetch > is broken"? Firstly performance, secondly user space exceptions. We work around lots of other broken CPU things this one triggers a path that only matters on Athlon. There is *one* change needed. We shouldnt call is_prefetch unless the current CPU is an Athlon. That way its a performance improvement for PIV, and Athlon in general, fixes the bug and causes no fancy athlon fixup code for non AMD processors. Alan