From: Orion Poplawski <orion@cora.nwra.com>
To: Alexander Graf <agraf@suse.de>
Cc: Gleb Natapov <gleb@redhat.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: Clock jumps
Date: Wed, 26 May 2010 16:55:48 -0600 [thread overview]
Message-ID: <4BFDA6F4.1080101@cora.nwra.com> (raw)
In-Reply-To: <4D7E210A-4694-4B6E-B721-6024CE96ABC0@suse.de>
On 05/26/2010 11:31 AM, Alexander Graf wrote:
>
> On 26.05.2010, at 19:10, Orion Poplawski wrote:
>
>> On 05/25/2010 12:21 AM, Gleb Natapov wrote:
>>> Adding kvm to CC.
>>>
>>> On Mon, May 24, 2010 at 04:06:32PM +0000, Orion Poplawski wrote:
>>>> I have a KVM virtual machine running 2.6.33.4-95.fc13.x86_64 on a CentOS 5.5
>>>> host whose clock jumps about 8-12 hours a couple times a day. I have no idea
>>>> what is causing it. Fedora 12 and Centos 5.5 KVM machines run fine on the same
>>>> host. Is there any debugging I can enable to see what is jumping the clock?
>>>>
>>>> kvm-clock: cpu 0, msr 0:1ba4741, boot clock
>>>> kvm-clock: cpu 0, msr 0:1e15741, primary cpu clock
>>>> Switching to clocksource kvm-clock
>>>> rtc_cmos 00:01: setting system clock to 2010-05-20 16:59:48 UTC (1274374788)
>>
>>
>> Thanks, though I don't think it made it there. I'm also not sure it's completely limited to KVM, though that is the only running system I am currently seeing the problem on. I also see clock jumps during anaconda installs on physical hardware and apparently they have been present since at least F11. Might be unrelated though.
>>
>> I'm really at a loss of how to debug this though.
>
> Do you have ntpd running inside the guest? I have a bug report lying around about 2.6.33 with kvm-clock jumping in time when ntpd is used: https://bugzilla.novell.com/show_bug.cgi?id=582260
>
> Alex
>
That bug looks just like what I'm seeing. I even see the soft lockup messages
sometimes as well. May actually be seeing it with a Fedora 12 guest as well -
but it results in a hard hang.
--
Orion Poplawski
Technical Manager 303-415-9701 x222
NWRA/CoRA Division FAX: 303-415-9702
3380 Mitchell Lane orion@cora.nwra.com
Boulder, CO 80301 http://www.cora.nwra.com
next prev parent reply other threads:[~2010-05-26 22:56 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-24 16:06 Clock jumps Orion Poplawski
2010-05-25 6:21 ` Gleb Natapov
2010-05-26 17:10 ` Orion Poplawski
2010-05-26 17:31 ` Alexander Graf
2010-05-26 17:50 ` Orion Poplawski
2010-05-26 22:55 ` Orion Poplawski [this message]
2010-05-27 18:32 ` Bernhard Schmidt
2010-05-27 18:32 ` Bernhard Schmidt
2010-05-27 19:08 ` john stultz
2010-05-27 21:48 ` Bernhard Schmidt
2010-05-28 0:00 ` john stultz
2010-05-28 0:33 ` Bernhard Schmidt
2010-05-28 0:46 ` john stultz
2010-05-28 0:49 ` Bernhard Schmidt
2010-05-27 21:53 ` Zachary Amsden
2010-05-27 22:12 ` Bernhard Schmidt
2010-05-27 22:20 ` Zachary Amsden
2010-05-27 22:22 ` Zachary Amsden
2010-06-02 22:54 ` Orion Poplawski
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