From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rkxYf5RZhzDr07 for ; Wed, 6 Jul 2016 20:19:02 +1000 (AEST) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u66AIwGY146347 for ; Wed, 6 Jul 2016 06:19:00 -0400 Received: from e28smtp05.in.ibm.com (e28smtp05.in.ibm.com [125.16.236.5]) by mx0a-001b2d01.pphosted.com with ESMTP id 240nm9974q-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 06 Jul 2016 06:18:59 -0400 Received: from localhost by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 6 Jul 2016 15:48:51 +0530 Received: from d28relay10.in.ibm.com (d28relay10.in.ibm.com [9.184.220.161]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id D190DE0040 for ; Wed, 6 Jul 2016 15:52:45 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay10.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u66AInva29491254 for ; Wed, 6 Jul 2016 15:48:49 +0530 Received: from d28av01.in.ibm.com (localhost [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u66AIhtL014458 for ; Wed, 6 Jul 2016 15:48:49 +0530 Date: Wed, 06 Jul 2016 18:18:27 +0800 From: xinhui 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 Message-Id: <577CDAF3.4030401@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 >