Re: Strange error in domU after dom0 update

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 10/22/09 04:55, Andreas Florath wrote:
> What I recognized is, that the domU on xen-unstable is somewhat slower
> than on the working xen-3.2.1 system. Had a closer look at the boot
> messages and found one difference:
>
> xen-3.2.1 system:
> [    0.000000] Xen reported: 2793.000 MHz processor.
>
> xen-unstable:
> [    0.000000] Xen reported: 1000.000 MHz processor.
>
> Except from /proc/cpuinfo of the dom0 (both versions):
> model name    : Intel(R) Pentium(R) 4 CPU 2.80GHz
> cpu MHz        : 2793.002
>
> I'm completely unsure if this has something to do with the problem -
> but at least it can explain something.
>
> Can anybody please tell me, if this is a bug or a feature - or maybe
> even a configuration parameter?

xen-unstable currently always traps and emulates rdtsc, so that tsc
appears to be running at 1GHz.  Set "tsc_native = 1" in your config file
to return to the old behaviour.  It shouldn't have a dramatic effect on
your domain's performance (perhaps a few percent improvement).

    J