Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261245AbTIKO30 (ORCPT ); Thu, 11 Sep 2003 10:29:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261258AbTIKO3Z (ORCPT ); Thu, 11 Sep 2003 10:29:25 -0400 Received: from pix-525-pool.redhat.com ([66.187.233.200]:64158 "EHLO lacrosse.corp.redhat.com") by vger.kernel.org with ESMTP id S261245AbTIKO3V (ORCPT ); Thu, 11 Sep 2003 10:29:21 -0400 Date: Thu, 11 Sep 2003 15:28:09 +0100 From: Dave Jones To: Andi Kleen Cc: Alan Cox , torvalds@osdl.org, richard.brunner@amd.com, linux-kernel@vger.kernel.org, akpm@osdl.org Subject: Re: [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata Message-ID: <20030911142809.GB20434@redhat.com> Mail-Followup-To: Dave Jones , Andi Kleen , Alan Cox , torvalds@osdl.org, richard.brunner@amd.com, linux-kernel@vger.kernel.org, akpm@osdl.org References: <1063289641.2967.3.camel@dhcp23.swansea.linux.org.uk> <20030911162421.419f4432.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030911162421.419f4432.ak@suse.de> User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 742 Lines: 18 On Thu, Sep 11, 2003 at 04:24:21PM +0200, Andi Kleen wrote: > I considered that when writing the patch, but: is_prefetch is a single byte > memory access for something already in cache. Checking for an Athlon > CPU needs two memory accesses in boot_cpu_data at least (checking vendor > and model) You only need to check it once when the path is first taken, and then set a variable that makes you exit as soon as you enter it again. Dave -- Dave Jones http://www.codemonkey.org.uk - 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/