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Re: [Xen-users] 47s clock skew in domUs every so often, Debian squeeze p

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Subject: Re: [Xen-users] 47s clock skew in domUs every so often, Debian squeeze packaged hypervisor 4.0.1-2
From: Steve Allison <stalks@xxxxxxxxxxx>
Date: Wed, 21 Sep 2011 18:01:48 +0100
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On 21/09/2011 16:56, Andy Smith wrote:
Hi Steven,

On Wed, Sep 21, 2011 at 08:55:08AM -0500, Steven Timm wrote:
What's your setting for /proc/sys/xen/independent_wallclock?
Not sure if that was for Steve or myself, but since most of the
domUs I have access to are using pvops kernels they don't have an
independent_wallclock setting at all.

Steve,

On Wed, 21 Sep 2011, Steve Allison wrote:
On 20/09/2011 22:02, Andy Smith wrote:
         Current      Available
         clocksource  clocksources
-----------------------------------
dom0   xen          xen
foo2   tsc          xen tsc
test0  xen          xen tsc jiffies
bar0   xen          xen tsc
[...]

Add this to /etc/default/grub

GRUB_CMDLINE_XEN_DEFAULT="clocksource=pit"
Will that actually work given that dom0 does not list "pit" as an
available clocksource?

If/when I do reboot the dom0, what should I be looking for in the xm
dmesg and dom0 dmesg that will give some info about clock sources?

Cheers,
Andy

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I think dom0 will only ever list "xen" as its clocksource because of the type of virtual machine it is. I think to get the true clocksource listing you need to boot without the hypervisor.

Whilst using pit I get the following lines...

> xm dmesg|grep -i pit
(XEN) Command line: placeholder clocksource=pit
(XEN) Platform timer is 1.193MHz PIT

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