From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266083AbTIKEz3 (ORCPT ); Thu, 11 Sep 2003 00:55:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266086AbTIKEz3 (ORCPT ); Thu, 11 Sep 2003 00:55:29 -0400 Received: from amdext2.amd.com ([163.181.251.1]:40695 "EHLO amdext2.amd.com") by vger.kernel.org with ESMTP id S266083AbTIKEzX (ORCPT ); Thu, 11 Sep 2003 00:55:23 -0400 Message-ID: <99F2150714F93F448942F9A9F112634C0638B197@txexmtae.amd.com> From: richard.brunner@amd.com To: linux-kernel@vger.kernel.org Subject: RE: [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata Date: Wed, 10 Sep 2003 23:55:09 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) X-WSS-ID: 137EDFA41955605-01-01 Content-Type: text/plain Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jun, I have to agree with what Andi says. It is in a slow path, and we want to guard against user programs that could hit it. Making it conditional doesn't buy a lot and would cause lots of re-validation of the patch that we would like to avoid so we can get this in to the 2.6 kernel ASAP. Don't worry! I am pretty certain the patch won't impact the performance of the 2.6 kernel on processors from other vendors ;-) Thanks! ]-Rich ... ]AMD Fellow > From: Nakajima, Jun [mailto:jun.nakajima@intel.com] > > > I would hate to break this again just to save a few hundred bytes in > > this function. Also the overhead is very low so it is also not > > interesting to make it conditional for speed reasons. > > For maintenance and testing purposes, I think it's still > better to make it conditional. If the errata are fixed, you > might want to kill the condition depending on the stepping, > for example. During the transition time, you need to support > both the steppings until old ones go away (then remove the > workaround). > > Thanks, > Jun