From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760392Ab0LOBIR (ORCPT ); Tue, 14 Dec 2010 20:08:17 -0500 Received: from terminus.zytor.com ([198.137.202.10]:50730 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757455Ab0LOBIQ (ORCPT ); Tue, 14 Dec 2010 20:08:16 -0500 Message-ID: <4D0814AF.7080209@zytor.com> Date: Tue, 14 Dec 2010 17:06:55 -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.fc13 Thunderbird/3.1.7 MIME-Version: 1.0 To: Tejun Heo CC: Christoph Lameter , Eric Dumazet , akpm@linux-foundation.org, Pekka Enberg , linux-kernel@vger.kernel.org, Mathieu Desnoyers Subject: Re: [cpuops cmpxchg V2 5/5] cpuops: Use cmpxchg for xchg to avoid lock semantics References: <20101214162842.542421046@linux.com> <20101214162855.392020353@linux.com> <1292345072.5934.32.camel@edumazet-laptop> <4D07A2B7.8080405@zytor.com> <4D07A7CB.7010205@zytor.com> <4D07A95C.7030703@kernel.org> In-Reply-To: <4D07A95C.7030703@kernel.org> 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 12/14/2010 09:29 AM, Tejun Heo wrote: > Hello, > > On 12/14/2010 06:22 PM, H. Peter Anvin wrote: >> On 12/14/2010 09:19 AM, Christoph Lameter wrote: >>>> >>>> Is it genuinely faster to do the pre-load mov, or can we drop that too? >>>> My guess would be that yes it is, but if it happens not to be it would >>>> be nice to reduce the code size. >>> >>> Dropping the load increases the cycle count from 11 to 16. >> >> Great, that answers that! I'll pick up the patch hopefully today (I'm >> finally ramping back up on arch/x86 again after having been diverted to >> an internal project for a while...) > > How do you want to route these? All patches before this series is > already in the percpu tree. I can pull the generic bits and leave out > the x86 bits so that x86 tree can pull in percpu bits and then put x86 > stuff on top of it. If you wanna go that way, I would drop all x86 > related patches from the previous patchsets too. > It's probably easiest if you just add them with my Acked-by: then. Alternatively, I could pick them up so they go into -tip and the tip test machinery. -hpa