From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: smp guest questions Date: Thu, 18 Jun 2009 12:17:52 -0300 Message-ID: <20090618151752.GA5494@amt.cnet> References: <4A38ABA3.2010401@msgid.tls.msk.ru> <4A38B43E.6010704@redhat.com> <4A38C997.5020005@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity , KVM list To: Michael Tokarev , Zachary Amsden Return-path: Received: from mx2.redhat.com ([66.187.237.31]:39945 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752022AbZFRPSB (ORCPT ); Thu, 18 Jun 2009 11:18:01 -0400 Content-Disposition: inline In-Reply-To: <4A38C997.5020005@msgid.tls.msk.ru> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Jun 17, 2009 at 02:46:47PM +0400, Michael Tokarev wrote: > Avi Kivity wrote: >> 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). > > The guest kernel is also 2.6.29[.5], but this time it's x86-32 > (compiled for P4). kvm userspace is also 32bits (historical) -- > only host kernel is 64bit for now. I'll try to do some more > experiments later today on a test machine (this is a production > box) -- "hopefully" that same issue will occur on another > machine :) kernel tries to correlate pm-timer with PIT: http://lxr.linux.no/linux+v2.6.17/arch/i386/kernel/timers/timer_pm.c#L95 http://lxr.linux.no/linux+v2.6.17/include/asm-i386/mach-default/mach_timer.h#L39 Should be fixed before the Brazil world cup.