From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Fjellstrom Subject: Re: kvm linux guest hanging for minutes at a time Date: Tue, 9 Aug 2011 08:46:14 -0600 Message-ID: <201108090846.14525.thomas@fjellstrom.ca> References: <201108070806.59194.thomas@fjellstrom.ca> <201108090831.48423.thomas@fjellstrom.ca> <4E414615.8030201@redhat.com> Reply-To: thomas@fjellstrom.ca Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" To: Avi Kivity Return-path: Received: from mail.tomasu.net ([64.85.170.232]:36063 "EHLO mail.tomasu.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752006Ab1HIOqU (ORCPT ); Tue, 9 Aug 2011 10:46:20 -0400 In-Reply-To: <4E414615.8030201@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On August 9, 2011, Avi Kivity wrote: > On 08/09/2011 05:31 PM, Thomas Fjellstrom wrote: > > On August 9, 2011, Avi Kivity wrote: > > > On 08/09/2011 03:03 PM, Thomas Fjellstrom wrote: > > > > > Your guest isn't using kvmclock for some reason. Is it > > > > > compiled in the guest kernel? What are the contents of > > > > > /sys/devices/system/clocksource/clocksource0/available_clocksou > > > > > rce and > > > > > /sys/devices/system/clocksource/clocksource0/current_clocksour > > > > > ce (in the guest filesystem)? > > > > > > > > Hi, it seems it is using kvm-clock: > > > > > > > > $ cat > > > > /sys/devices/system/clocksource/clocksource0/available_clocksource > > > > kvm-clock hpet acpi_pm > > > > $ cat > > > > /sys/devices/system/clocksource/clocksource0/current_clocksource > > > > kvm-clock > > > > > > Yikes. Please trace such a hang according to > > > http://www.linux-kvm.org/page/Tracing. > > > > Does it matter that I have several vms running? Is there a way to limit > > it to tracing the single kvm process that's been locking up? > > You can use "trace-cmd record -F ... qemu ..." but that misses out on > events the run from workqueues. > > Best to stop those other guests. I would prefer not to do that, those other guests are my web server, mail server, and database server. I have no idea if I can reproduce the problem in a reasonable time frame. -- Thomas Fjellstrom thomas@fjellstrom.ca