From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755120Ab0ANHD3 (ORCPT ); Thu, 14 Jan 2010 02:03:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754904Ab0ANHD2 (ORCPT ); Thu, 14 Jan 2010 02:03:28 -0500 Received: from terminus.zytor.com ([198.137.202.10]:37389 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754835Ab0ANHD2 (ORCPT ); Thu, 14 Jan 2010 02:03:28 -0500 Message-ID: <4B4EC1A5.4010701@zytor.com> Date: Wed, 13 Jan 2010 23:03:01 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-3.fc11 Thunderbird/3.0 MIME-Version: 1.0 To: Linus Torvalds CC: Ingo Molnar , Thomas Gleixner , Linux Kernel Mailing List Subject: Re: x86: clean up rwsem type system References: <4B4D1865.5000107@zytor.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/12/2010 06:16 PM, Linus Torvalds wrote: > > In case anybody wants to test, the final piece is appended. > > Again, note the 32767-thread limit here. So this really does need that > whole "make rwsem_count_t be 64-bit and fix the BIAS values to match" > extension on top of it, but that is conceptually a totally independent > issue. > > NOT TESTED! The original patch that this all was based on were tested by > KAMEZAWA Hiroyuki, but maybe I screwed up something when I created the > cleaned-up series, so caveat emptor.. > > Also note that it _may_ be a good idea to mark some more registers > clobbered on x86-64 in the inline asms instead of saving/restoring them. > They are inline functions, but they are only used in places where there > are not a lot of live registers _anyway_, so doing for example the > clobbers of %r8-%r11 in the asm wouldn't make the fast-path code any > worse, and would make the slow-path code smaller. > Hi Linus, I have put these into a separate topic branch in the tip tree, which should get them some test coverage. I will look at 64-bit counters to support 2^31 threads hopefully later this week, unless you prefer to do it yourself. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.