From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752199AbcGFKTF (ORCPT ); Wed, 6 Jul 2016 06:19:05 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:51105 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751223AbcGFKTC (ORCPT ); Wed, 6 Jul 2016 06:19:02 -0400 X-IBM-Helo: d28dlp01.in.ibm.com X-IBM-MailFrom: xinhui.pan@linux.vnet.ibm.com X-IBM-RcptTo: kvm@vger.kernel.org;linux-kernel@vger.kernel.org;linux-s390@vger.kernel.org Date: Wed, 06 Jul 2016 18:18:27 +0800 From: xinhui User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.8.0 MIME-Version: 1.0 To: Wanpeng Li , Peter Zijlstra CC: "linux-kernel@vger.kernel.org" , linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux-foundation.org, linux-s390 , Ingo Molnar , mpe@ellerman.id.au, Paul Mackerras , benh@kernel.crashing.org, Paul McKenney , Waiman Long , will.deacon@arm.com, boqun.feng@gmail.com, Davidlohr Bueso , schwidefsky@de.ibm.com, Paolo Bonzini , kvm Subject: Re: [PATCH v2 2/4] powerpc/spinlock: support vcpu preempted check References: <1467124991-13164-1-git-send-email-xinhui.pan@linux.vnet.ibm.com> <1467124991-13164-3-git-send-email-xinhui.pan@linux.vnet.ibm.com> <577C8FE3.3010208@linux.vnet.ibm.com> <20160706075814.GF30921@twins.programming.kicks-ass.net> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16070610-0016-0000-0000-000002C11CF1 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16070610-0017-0000-0000-000024B8D856 Message-Id: <577CDAF3.4030401@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-07-06_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1607060092 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016年07月06日 16:32, Wanpeng Li wrote: > 2016-07-06 15:58 GMT+08:00 Peter Zijlstra : >> On Wed, Jul 06, 2016 at 02:46:34PM +0800, Wanpeng Li wrote: >>>> SO it's easy for ppc to implement such interface. Note that yield_count is >>>> set by powerVM/KVM. >>>> and only pSeries can run a guest for now. :) >>>> >>>> I also review x86 related code, looks like we need add one hyer-call to get >>>> such vcpu preemption info? >>> >>> There is no such stuff to record lock holder in x86 kvm, maybe we >>> don't need to depend on PLE handler algorithm to guess it if we can >>> know lock holder vCPU directly. >> >> x86/kvm has vcpu->preempted to indicate if a vcpu is currently preempted >> or not. I'm just not sure if that is visible to the guest or how to make >> it so. > > Yeah, I miss it. I can be the volunteer to do it if there is any idea, > ping Paolo. :) > glad to know that. :) > Regards, > Wanpeng Li >