From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753310Ab2DQHWT (ORCPT ); Tue, 17 Apr 2012 03:22:19 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:36818 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751762Ab2DQHWR (ORCPT ); Tue, 17 Apr 2012 03:22:17 -0400 Message-ID: <4F8D168B.7090806@linux.vnet.ibm.com> Date: Tue, 17 Apr 2012 12:36:51 +0530 From: Raghavendra K T Organization: IBM User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120216 Thunderbird/10.0.1 MIME-Version: 1.0 To: Marcelo Tosatti CC: Ingo Molnar , "H. Peter Anvin" , X86 , Avi Kivity , Jeremy Fitzhardinge , Konrad Rzeszutek Wilk , Greg Kroah-Hartman , Alexander Graf , Stefano Stabellini , Gleb Natapov , Randy Dunlap , linux-doc@vger.kernel.org, LKML , KVM , Virtualization , Xen , Sasha Levin , Srivatsa Vaddagiri Subject: Re: [PATCH RFC V5 2/6] kvm hypervisor : Add a hypercall to KVM hypervisor to support pv-ticketlocks References: <20120323080503.14568.43092.sendpatchset@codeblue> <20120323080701.14568.97779.sendpatchset@codeblue> <20120412000629.GA32051@amt.cnet> <20120412002909.GD32051@amt.cnet> In-Reply-To: <20120412002909.GD32051@amt.cnet> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit x-cbid: 12041621-5140-0000-0000-000001156796 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/12/2012 05:59 AM, Marcelo Tosatti wrote: > On Wed, Apr 11, 2012 at 09:06:29PM -0300, Marcelo Tosatti wrote: >> On Fri, Mar 23, 2012 at 01:37:04PM +0530, Raghavendra K T wrote: >>> From: Srivatsa Vaddagiri >>> [...] barrier(); >> >> Is it always OK to erase the notification, even in case an unrelated >> event such as interrupt was the source of wakeup? > > Note i am only asking whether it is OK to lose a notification, not > requesting a change to atomic test-and-clear. Yes.. got your point. IMO, this is the only (safe) place where it can clear kicked(pv_unhalted) flag. Since it is going to be runnable. and you are also right in having concern on unwanted clear of flag since that would result in vcpu /vm hangs eventually. Hope I did not miss anything. > > It would be nice to have a comment explaining it. > Sure will do that >> From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raghavendra K T Subject: Re: [PATCH RFC V5 2/6] kvm hypervisor : Add a hypercall to KVM hypervisor to support pv-ticketlocks Date: Tue, 17 Apr 2012 12:36:51 +0530 Message-ID: <4F8D168B.7090806@linux.vnet.ibm.com> References: <20120323080503.14568.43092.sendpatchset@codeblue> <20120323080701.14568.97779.sendpatchset@codeblue> <20120412000629.GA32051@amt.cnet> <20120412002909.GD32051@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Cc: Jeremy Fitzhardinge , Greg Kroah-Hartman , KVM , Gleb Natapov , Konrad Rzeszutek Wilk , X86 , linux-doc@vger.kernel.org, Alexander Graf , LKML , Randy Dunlap , Ingo Molnar , Srivatsa Vaddagiri , Avi Kivity , "H. Peter Anvin" , Virtualization , Xen , Stefano Stabellini , Sasha Levin To: Marcelo Tosatti Return-path: In-Reply-To: <20120412002909.GD32051@amt.cnet> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org List-Id: kvm.vger.kernel.org On 04/12/2012 05:59 AM, Marcelo Tosatti wrote: > On Wed, Apr 11, 2012 at 09:06:29PM -0300, Marcelo Tosatti wrote: >> On Fri, Mar 23, 2012 at 01:37:04PM +0530, Raghavendra K T wrote: >>> From: Srivatsa Vaddagiri >>> [...] barrier(); >> >> Is it always OK to erase the notification, even in case an unrelated >> event such as interrupt was the source of wakeup? > > Note i am only asking whether it is OK to lose a notification, not > requesting a change to atomic test-and-clear. Yes.. got your point. IMO, this is the only (safe) place where it can clear kicked(pv_unhalted) flag. Since it is going to be runnable. and you are also right in having concern on unwanted clear of flag since that would result in vcpu /vm hangs eventually. Hope I did not miss anything. > > It would be nice to have a comment explaining it. > Sure will do that >>