From mboxrd@z Thu Jan 1 00:00:00 1970 From: "SourceForge.net" Subject: [ kvm-Bugs-3055533 ] guest clock runs 2 times faster than the host clock Date: Sun, 29 Aug 2010 20:55:14 +0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" To: noreply@sourceforge.net Return-path: Received: from ch3.sourceforge.net ([216.34.181.60]:31017 "EHLO ch3.sourceforge.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753720Ab0H2UzS (ORCPT ); Sun, 29 Aug 2010 16:55:18 -0400 Sender: kvm-owner@vger.kernel.org List-ID: Bugs item #3055533, was opened at 2010-08-29 18:07 Message generated for change (Comment added) made by bcv You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=3055533&group_id=180599 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: intel Group: None Status: Open Resolution: None Priority: 7 Private: No Submitted By: Bhasker C V (bcv) Assigned to: Nobody/Anonymous (nobody) Summary: guest clock runs 2 times faster than the host clock Initial Comment: Host: processor: Intel(R) Core(TM)2 Quad CPU @ 2.66GHz OS : debian squeeze Qemu : qemu-kvm-88 Kernel : Linux bcv 2.6.35.3 #1 SMP PREEMPT Mon Aug 23 17:55:19 BST 2010 x86_64 GNU/Linux Guest: processsor: Intel core2duo smp 2 OS : SUSE linux enterprise 10 64bit so running a 64 bit OS on 64 bit debian host. The clock runs double fast than the host OS. This results in guest gaining time and going ahead the host ---------------------------------------------------------------------- >Comment By: Bhasker C V (bcv) Date: 2010-08-29 21:55 Message: A quick workaround for this solution would be to use the following in the kernel command line along with using -clock dynticks append this notsc divider=10 clock=pmtmr the clock= option may change for various distributions and can be lookedup from http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006427 Albeit this fairly makes the clock not to go haywire and keep counting fast, there is still a small gain which can be well managed using ntp or periodic rdate updates ---------------------------------------------------------------------- Comment By: Michael Tokarev (mjtsf) Date: 2010-08-29 19:45 Message: Come on, kvm-88 is ancient unsupported development snapshot. It isnt' even an alpha version. Please try current code (at least qemu-kvm-0.12.4 as available on backports.org) and file a new bugreport if the problem is still here. And if the issue _is_ present in real version, please file a bug in launchpad.net against qemu project, not here. This bugtracker is dead. Thanks. ---------------------------------------------------------------------- Comment By: Bhasker C V (bcv) Date: 2010-08-29 18:25 Message: Running a 32 bit OS instead of the 64 bit OS maintains time properly. It is just that running the 64 bit OS inside this qemu-kvm makes the guest to gain time. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=3055533&group_id=180599