From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933965AbcLIQK1 (ORCPT ); Fri, 9 Dec 2016 11:10:27 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37594 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933943AbcLIQKY (ORCPT ); Fri, 9 Dec 2016 11:10:24 -0500 Subject: Re: [PATCH-tip] locking/pvqspinlock: Relax cmpxchg's to improve performance on some archs To: Peter Zijlstra References: <1481051682-29438-1-git-send-email-longman@redhat.com> <20161209160534.GX3124@twins.programming.kicks-ass.net> Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Pan Xinhui , Boqun Feng , Will Deacon From: Waiman Long Organization: Red Hat Message-ID: <192df241-642b-9b04-dd5c-31597bf9c574@redhat.com> Date: Fri, 9 Dec 2016 11:10:23 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20161209160534.GX3124@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 09 Dec 2016 16:10:24 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/09/2016 11:05 AM, Peter Zijlstra wrote: > On Tue, Dec 06, 2016 at 02:14:42PM -0500, Waiman Long wrote: >> A number of cmpxchg calls in qspinlock_paravirt.h were replaced by more >> relaxed versions to improve performance on architectures that use LL/SC. > I would feel so much better if each change were to have some rationale > included. Either enumerate them in the changelog, or split them up into > smaller patches. > > OK, I will update the patch to either document them with comments or enumerate them in the change log. Cheers, Longman