From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762314AbXKTCNf (ORCPT ); Mon, 19 Nov 2007 21:13:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760627AbXKTCAm (ORCPT ); Mon, 19 Nov 2007 21:00:42 -0500 Received: from terminus.zytor.com ([198.137.202.10]:50700 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760480AbXKTCAl (ORCPT ); Mon, 19 Nov 2007 21:00:41 -0500 Message-ID: <47423FB7.20800@zytor.com> Date: Mon, 19 Nov 2007 18:00:23 -0800 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Christoph Lameter CC: ak@suse.de, akpm@linux-foundation.org, travis@sgi.com, Mathieu Desnoyers , linux-kernel@vger.kernel.org Subject: Re: [rfc 37/45] x86_64: Support for fast per cpu operations References: <20071120011132.143632442@sgi.com> <20071120011340.569486037@sgi.com> In-Reply-To: <20071120011340.569486037@sgi.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Christoph Lameter wrote: > Support fast cpu ops in x86_64 by providing a series of functions that > generate the proper instructions. Define CONFIG_FAST_CPU_OPS so that core code > can exploit the availability of fast per cpu operations. > > Signed-off-by: Christoph Lameter There was, at some point, discussion about using the gcc TLS mechanism, which should permit even better code to be generated. Unfortunately, it would require gcc to be able to reference %gs instead of %fs (and vice versa for i386), which I don't think is available in anything except maybe the most cutting-edge version of gcc. However, if we're doing a masssive revampt it would be good to get an idea of how to migrate to that model eventually, or why it doesn't make sense at all. -hpa