From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: Re: [PATCH v9 03/19] qspinlock: Add pending bit Date: Fri, 18 Apr 2014 13:07:14 -0400 Message-ID: <53515BC2.6000602@hp.com> References: <1397747051-15401-1-git-send-email-Waiman.Long@hp.com> <1397747051-15401-4-git-send-email-Waiman.Long@hp.com> <20140417154200.GN11096@twins.programming.kicks-ass.net> <5350459F.5010903@hp.com> <20140418081345.GX11096@twins.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140418081345.GX11096@twins.programming.kicks-ass.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Peter Zijlstra Cc: linux-arch@vger.kernel.org, Rik van Riel , Raghavendra K T , Gleb Natapov , kvm@vger.kernel.org, Konrad Rzeszutek Wilk , Scott J Norton , x86@kernel.org, Paolo Bonzini , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Ingo Molnar , Chegu Vinod , David Vrabel , "H. Peter Anvin" , xen-devel@lists.xenproject.org, Thomas Gleixner , "Paul E. McKenney" , Linus Torvalds , Oleg Nesterov List-Id: linux-arch.vger.kernel.org On 04/18/2014 04:13 AM, Peter Zijlstra wrote: > On Thu, Apr 17, 2014 at 05:20:31PM -0400, Waiman Long wrote: >>>> + while ((val = atomic_read(&lock->val))& _Q_LOCKED_MASK) >>>> + arch_mutex_cpu_relax(); >>> That was a cpu_relax(). >> Yes, but arch_mutex_cpu_relax() is the same as cpu_relax() for x86. > Yeah, so why bother typing more? > > Let the s390 people sort that if/when they try and make this work for > them. OK, I can revert the change if you wish. I have no objection for that. -Longman From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from g2t2352.austin.hp.com ([15.217.128.51]:25892 "EHLO g2t2352.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751646AbaDRRHd (ORCPT ); Fri, 18 Apr 2014 13:07:33 -0400 Message-ID: <53515BC2.6000602@hp.com> Date: Fri, 18 Apr 2014 13:07:14 -0400 From: Waiman Long MIME-Version: 1.0 Subject: Re: [PATCH v9 03/19] qspinlock: Add pending bit References: <1397747051-15401-1-git-send-email-Waiman.Long@hp.com> <1397747051-15401-4-git-send-email-Waiman.Long@hp.com> <20140417154200.GN11096@twins.programming.kicks-ass.net> <5350459F.5010903@hp.com> <20140418081345.GX11096@twins.programming.kicks-ass.net> In-Reply-To: <20140418081345.GX11096@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Peter Zijlstra Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, kvm@vger.kernel.org, Paolo Bonzini , Konrad Rzeszutek Wilk , "Paul E. McKenney" , Rik van Riel , Linus Torvalds , Raghavendra K T , David Vrabel , Oleg Nesterov , Gleb Natapov , Scott J Norton , Chegu Vinod Message-ID: <20140418170714.-HCRs86_NQ0rdSue_9R9xhSTSqjybbzez2rI1f2d5BM@z> On 04/18/2014 04:13 AM, Peter Zijlstra wrote: > On Thu, Apr 17, 2014 at 05:20:31PM -0400, Waiman Long wrote: >>>> + while ((val = atomic_read(&lock->val))& _Q_LOCKED_MASK) >>>> + arch_mutex_cpu_relax(); >>> That was a cpu_relax(). >> Yes, but arch_mutex_cpu_relax() is the same as cpu_relax() for x86. > Yeah, so why bother typing more? > > Let the s390 people sort that if/when they try and make this work for > them. OK, I can revert the change if you wish. I have no objection for that. -Longman