From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753927Ab3JMIJa (ORCPT ); Sun, 13 Oct 2013 04:09:30 -0400 Received: from e23smtp04.au.ibm.com ([202.81.31.146]:34547 "EHLO e23smtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753759Ab3JMIJZ (ORCPT ); Sun, 13 Oct 2013 04:09:25 -0400 Message-ID: <525A5519.2050205@linux.vnet.ibm.com> Date: Sun, 13 Oct 2013 13:38:57 +0530 From: Raghavendra K T Organization: IBM User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: mingo@redhat.com, hpa@zytor.com, tglx@linutronix.de CC: Raghavendra K T , x86@kernel.org, gleb@redhat.com, pbonzini@redhat.com, konrad.wilk@oracle.com, habanero@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, mtosatti@redhat.com, Steven Rostedt Subject: Re: [PATCH] kvm fix: Enable pvspinlock after jump_label_init() to avoid VM hang References: <1381309401-23663-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> In-Reply-To: <1381309401-23663-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13101308-9264-0000-0000-000004B472FF Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/09/2013 02:33 PM, Raghavendra K T wrote: > We use jump label to enable pv-spinlock. With the changes in > (442e0973e927 Merge branch 'x86/jumplabel'), the jump label behaviour has changed > that would result in evntual hang of the VM since we would end up in a situation > where slowpath locks would halt the vcpus but we will not be able to wakeup the > vcpu by lock releaser using unlock kick. > > Similar problem in Xen and more detailed description is available in > a945928ea270 (xen: Do not enable spinlocks before jump_label_init() has executed) > > This patch splits kvm_spinlock_init to separate jump label changes with pvops > patching and also make jump label enabling after jump_label_init(). > > Signed-off-by: Raghavendra K T Ingo, Could you please take this fix? This is reviewed by Paolo and Steven.