From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark McLoughlin Subject: Re: KVM guest lockup Date: Mon, 12 Jan 2009 17:09:20 +0000 Message-ID: <1231780160.4290.164.camel@localhost.localdomain> References: <20081219174401.GA2730@squirrel.roonstrasse.net> <20081221115538.GA25958@x61s.gondor.com> <20081222105738.GA27409@squirrel.roonstrasse.net> Reply-To: Mark McLoughlin Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Jan Niehusmann , kvm@vger.kernel.org To: Max Kellermann Return-path: Received: from mx2.redhat.com ([66.187.237.31]:39511 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752822AbZALRJh (ORCPT ); Mon, 12 Jan 2009 12:09:37 -0500 In-Reply-To: <20081222105738.GA27409@squirrel.roonstrasse.net> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, 2008-12-22 at 11:57 +0100, Max Kellermann wrote: > On 2008/12/21 12:55, Jan Niehusmann wrote: > > As I observed such behaviour only when the host has frequency > > scaling activated: Could it be that in this case, > > clocksource_read(clock) on the guest is misbehaving? > > Indeed, the host had governor=ondemand. After the switch to > "performance", the guest seems to run stable. > > So this is a bug in the guest kernel, by making wrong assumptions on > the clock values retrieved from the host, right? FWIW, several Fedora users are also seeing guest lockups with kvm-clock in the guest and frequency scaling enabled in the host. See: https://bugzilla.redhat.com/475598 Cheers, Mark.