Re: kvm somehow exempt from frequency scaling?

David Abrahams
2007-04-11T16:37:54Z

on Wed Apr 11 2007, David Abrahams <dave-UB3wUj7V41K5azolltMz9laTQe2KTcn/-AT-public.gmane.org> wrote:

> on Tue Apr 10 2007, Michael Riepe <michael-0QoEqw4nQxo-AT-public.gmane.org> wrote:
>
>> Hi!
>>
>> Avi Kivity wrote:
>>
>>> Sounds like ondemand is broken.
>>
>> Maybe it only switches when the load rises in user space. With KVM, it
>> appears in system space. Got to cross-check that on my Core Duo.
>
> More data: it definitely seems to make a difference whether the VM's
> desktop is showing. If I switch Gnome workspaces so it's not visible,
> it doesn't seem to drive the frequency up.

In fact, kvm doesn't seem to make any progress at all :(. I'm
currently going through the "microsoft update" dance on a VM there,
and I literally left for an hour during which there was no progress
because the QEMU window wasn't visible.

Even stranger, if I minimize the QEMU window and then switch
workspaces, it gets plenty of cycles.

--
Dave Abrahams
Boost Consulting