From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751574Ab1AXGCT (ORCPT ); Mon, 24 Jan 2011 01:02:19 -0500 Received: from terminus.zytor.com ([198.137.202.10]:50880 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751410Ab1AXGCS (ORCPT ); Mon, 24 Jan 2011 01:02:18 -0500 Message-ID: <4D3D15AF.30508@zytor.com> Date: Sun, 23 Jan 2011 22:01:19 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7 MIME-Version: 1.0 To: Tejun Heo CC: Mathieu Desnoyers , Pekka Enberg , Christoph Lameter , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Eric Dumazet Subject: Re: [cpuops cmpxchg double V2 1/4] Generic support for this_cpu_cmpxchg_double References: <20110107180419.GB23082@Krystal> <20110108172453.GF13269@mtj.dyndns.org> <4D393636.4040607@cs.helsinki.fi> <20110121092649.GA2832@htj.dyndns.org> <4D39A6EB.70705@zytor.com> <20110121154831.GE2832@htj.dyndns.org> <20110121165425.GB11687@Krystal> <20110121170847.GH2832@htj.dyndns.org> <1da7491b-6e7d-4453-9c6f-0e7767421ec4@email.android.com> <20110121171914.GJ2832@htj.dyndns.org> In-Reply-To: <20110121171914.GJ2832@htj.dyndns.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/21/2011 09:19 AM, Tejun Heo wrote: > On Fri, Jan 21, 2011 at 09:13:41AM -0800, H. Peter Anvin wrote: >> We could do cmpxchg with a structure... the problem with a lon int >> type is that Cristoph ran into bugs with __int128 on 64 bits. > > But, IIRC, the problem with int128 was with passing it as parameter > and return value. We don't have to do that. We'll be just using it > as a data storage / container type. Or even that is broken? Well, part of the point was to pass in registers. No idea on the data storage type. -hpa