From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755599AbaCQRr6 (ORCPT ); Mon, 17 Mar 2014 13:47:58 -0400 Received: from g6t1526.atlanta.hp.com ([15.193.200.69]:30285 "EHLO g6t1526.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752668AbaCQRr5 (ORCPT ); Mon, 17 Mar 2014 13:47:57 -0400 Message-ID: <53273532.1010003@hp.com> Date: Mon, 17 Mar 2014 13:47:30 -0400 From: Waiman Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.12) Gecko/20130109 Thunderbird/10.0.12 MIME-Version: 1.0 To: Paolo Bonzini CC: Jeremy Fitzhardinge , Raghavendra K T , kvm@vger.kernel.org, Peter Zijlstra , virtualization@lists.linux-foundation.org, Andi Kleen , "H. Peter Anvin" , Michel Lespinasse , Alok Kataria , linux-arch@vger.kernel.org, Gleb Natapov , x86@kernel.org, Ingo Molnar , xen-devel@lists.xenproject.org, "Paul E. McKenney" , Arnd Bergmann , Scott J Norton , Steven Rostedt , Chris Wright , Thomas Gleixner , Aswin Chandramouleeswaran , Chegu Vinod , Boris Ostrovsky , Oleg Nesterov , linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC v6 10/11] pvqspinlock, x86: Enable qspinlock PV support for KVM References: <1394650498-30118-1-git-send-email-Waiman.Long@hp.com> <1394650498-30118-11-git-send-email-Waiman.Long@hp.com> <5321B9BE.7050209@redhat.com> <5322035B.5000205@hp.com> <5322C0F7.2090604@redhat.com> In-Reply-To: <5322C0F7.2090604@redhat.com> 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 03/14/2014 04:42 AM, Paolo Bonzini wrote: > Il 13/03/2014 20:13, Waiman Long ha scritto: >>>> >>> >>> This should also disable the unfair path. >>> >>> Paolo >>> >> >> The unfair lock uses a different jump label and does not require any >> special PV ops. There is a separate init function for that. > > Yeah, what I mean is that the patches that enable paravirtualization > should also take care of decreasing the unfair-lock jump label when > paravirtualization is enabled. > > Paolo As there are people who don't like unfair lock at all, I prefer to give them the option to turn this on or off instead of forcing them to always use unfair lock in a PV guest. -Longman From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: Re: [PATCH RFC v6 10/11] pvqspinlock, x86: Enable qspinlock PV support for KVM Date: Mon, 17 Mar 2014 13:47:30 -0400 Message-ID: <53273532.1010003@hp.com> References: <1394650498-30118-1-git-send-email-Waiman.Long@hp.com> <1394650498-30118-11-git-send-email-Waiman.Long@hp.com> <5321B9BE.7050209@redhat.com> <5322035B.5000205@hp.com> <5322C0F7.2090604@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5322C0F7.2090604@redhat.com> 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: Paolo Bonzini Cc: Jeremy Fitzhardinge , Raghavendra K T , Gleb Natapov , Peter Zijlstra , virtualization@lists.linux-foundation.org, Andi Kleen , "H. Peter Anvin" , Michel Lespinasse , Alok Kataria , linux-arch@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, Ingo Molnar , xen-devel@lists.xenproject.org, "Paul E. McKenney" , Arnd Bergmann , Scott J Norton , Steven Rostedt , Chris Wright , Thomas Gleixner , Aswin Chandramouleeswaran , Chegu Vinod , Boris Ostrovsky , Oleg Nesterov , linux-kernel@vger. List-Id: linux-arch.vger.kernel.org On 03/14/2014 04:42 AM, Paolo Bonzini wrote: > Il 13/03/2014 20:13, Waiman Long ha scritto: >>>> >>> >>> This should also disable the unfair path. >>> >>> Paolo >>> >> >> The unfair lock uses a different jump label and does not require any >> special PV ops. There is a separate init function for that. > > Yeah, what I mean is that the patches that enable paravirtualization > should also take care of decreasing the unfair-lock jump label when > paravirtualization is enabled. > > Paolo As there are people who don't like unfair lock at all, I prefer to give them the option to turn this on or off instead of forcing them to always use unfair lock in a PV guest. -Longman