From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752636Ab1LSM71 (ORCPT ); Mon, 19 Dec 2011 07:59:27 -0500 Received: from mx1.redhat.com ([209.132.183.28]:1563 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752478Ab1LSM7Z (ORCPT ); Mon, 19 Dec 2011 07:59:25 -0500 Message-ID: <4EEF351E.8040002@redhat.com> Date: Mon, 19 Dec 2011 14:59:10 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111115 Thunderbird/8.0 MIME-Version: 1.0 To: Marcelo Tosatti CC: Eric B Munson , mingo@redhat.com, hpa@zytor.com, arnd@arndb.de, ryanh@linux.vnet.ibm.com, aliguori@us.ibm.com, jeremy.fitzhardinge@citrix.com, levinsasha928@gmail.com, Jan Kiszka , kvm@vger.kernel.org, linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/5 V5] Avoid soft lockup message when KVM is stopped by host References: <1323116344-17911-1-git-send-email-emunson@mgebm.net> <4EDF7B0D.4060001@redhat.com> <20111214121622.GB18317@amt.cnet> <4EE8B53C.6070502@redhat.com> <20111214182101.GB21945@amt.cnet> <4EE9CA1C.3010801@redhat.com> <20111216093149.GA26982@amt.cnet> In-Reply-To: <20111216093149.GA26982@amt.cnet> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/16/2011 11:31 AM, Marcelo Tosatti wrote: > > > > > > Slow enough that progress of the watchdog thread is unable to keep up > > > with timer interrupt processing. This is considered a hang and > > > should be reported. > > > > It's not a guest hang though! > > No, but your host system is in such a load state that for the sake of > system usability you better print out a warning message. What's the point in printing it in the guest? The guest can't observe host conditions. > I don't see the advantage of preempt notifiers over the simple, paravirt > solution proposed? Note kvmclock is already paravirt. Right. > What do you want to be done in preempt notifiers? Measure what to > consider setting this flag? Preemption while TASK_RUNNING or TASK_UNINTERRUPTIBLE. -- error compiling committee.c: too many arguments to function