From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754580AbYISNUu (ORCPT ); Fri, 19 Sep 2008 09:20:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753907AbYISNUj (ORCPT ); Fri, 19 Sep 2008 09:20:39 -0400 Received: from tac.ki.iif.hu ([193.6.222.43]:41286 "EHLO tac.ki.iif.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753623AbYISNUh (ORCPT ); Fri, 19 Sep 2008 09:20:37 -0400 From: Ferenc Wagner To: Jeremy Fitzhardinge Cc: linux-kernel@vger.kernel.org, Xen-devel Subject: Re: doubled idle count References: <87vdwtfxng.fsf@tac.ki.iif.hu> <48D2AD5E.7040602@goop.org> Date: Fri, 19 Sep 2008 15:20:28 +0200 In-Reply-To: <48D2AD5E.7040602@goop.org> (Jeremy Fitzhardinge's message of "Thu, 18 Sep 2008 12:34:54 -0700") Message-ID: <87wsh8nug3.fsf@tac.ki.iif.hu> User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jeremy Fitzhardinge writes: > Ferenc Wagner wrote: > >> After upgrading a Xen virtual machine to Debian's 2.6.26-4 kernel, I >> noticed that the idle counter doubled its pace on one of the machines: >> [...] >> One out of three machines show this effect, with the exact same kernel >> and Xen versions (3.2.0, dom0 is Debian's stock Etch 2.6.18 kernel). >> They aren't hosted by the same machine, though: the misbehaving one is >> on a different installation with very similar hardware (3 vs 2 GHz). >> All the guest are paravirtual. > > So you're saying that they are identical Xen and guest kernel binaries, > but one of three is showing doubled idle time? Now I upgraded another domU, and that also shows this doubling effect, so I've got two domUs (running on xen2-ha) misbehaving, and other two (running on xen2) behaving correctly. On the first: wferi@xen2-ha:~$ sudo xm info host : xen2-ha release : 2.6.18-6-xen-686 version : #1 SMP Mon Aug 18 12:56:50 UTC 2008 machine : i686 nr_cpus : 4 nr_nodes : 1 cores_per_socket : 1 threads_per_core : 2 cpu_mhz : 3056 hw_caps : bfebfbff:00000000:00000000:00000080:00004400 total_memory : 3071 free_memory : 991 node_to_cpu : node0:0-3 xen_major : 3 xen_minor : 2 xen_extra : -1 xen_caps : xen-3.0-x86_32p xen_scheduler : credit xen_pagesize : 4096 platform_params : virt_start=0xf5800000 xen_changeset : unavailable cc_compiler : gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21) cc_compile_by : fs cc_compile_domain : debian.org cc_compile_date : Mon Mar 10 15:50:27 UTC 2008 xend_config_format : 4 while on the other the differing lines are: host : xen2 cpu_mhz : 1993 total_memory : 4991 free_memory : 2464 Hope this adds some useful info. -- Regards, Feri.