From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: smp guest questions Date: Wed, 17 Jun 2009 12:15:42 +0300 Message-ID: <4A38B43E.6010704@redhat.com> References: <4A38ABA3.2010401@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: KVM list , Marcelo Tosatti To: Michael Tokarev Return-path: Received: from mx2.redhat.com ([66.187.237.31]:50942 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753751AbZFQJPt (ORCPT ); Wed, 17 Jun 2009 05:15:49 -0400 In-Reply-To: <4A38ABA3.2010401@msgid.tls.msk.ru> Sender: kvm-owner@vger.kernel.org List-ID: On 06/17/2009 11:38 AM, Michael Tokarev wrote: > After seeing words from Avi about that smp guests > are ok now, I descided to try. And immediately > got a few questions. > > Running on a Phenom 9750 machine (PhenomI), AMD780G > chipset. Host is 2.6.29 x86-64, qemu-kvm 0.10.5, > guests are linux with kvm paravirt bits enabled, also > dynticks (on both host and guest). > > > When booting a 2-CPU guest, I see in dmesg: > > PM-Timer running at invalid rate: 200% of normal - aborting. > > and indeed, in available_clocksource there's no pmtimer. > Should I be concerned? It does not look healthy. > It's a bug, please post guest details (kernel version, bitness). Copying Marcelo. > > Some time later, I see stuff like: > > hrtimer: interrupt too slow, forcing clock min delta to 47210997 ns > > Which reminds me issues I had with broken hpet (time goes > back-n-forth with similar messages shown in dmesg, but > about hpet not hrtimer). Also does not look healthy. > > > I haven't seen either of the two messages above on any of > single-processor guests so far, at least with recent kernels > and kvm userspace, only on smp (2 cpu for now). Please also post host /proc/cpuifo. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.