Re: cpufreq status information

["Jan Beulich" <jbeulich@novell.com>]

>>> Keir Fraser <keir.fraser@eu.citrix.com> 08.09.08 16:00 >>>
>After all, guest performance is at least as affected by CPU (and other
>resources) contention from other guests as it is by power-management
>governors in the hyeprvisor. Indeed, if the governors are doing their job
>right then guest performance should not be considerably impacted by them
>even in absolute terms.

Right you say 'if' - what if not? How do I tell, especially when I can't touch
the system and easily put a patched hypervisor and/or kernel on. If we
get a complaint from a customer that he thinks frequency scaling doesn't
do what it's expected to, we'll need to have a simple mechanism at hand
to determine what's going on with his box.

And even for development purposes I think a one-look proof that things
work as expected is quite useful (I'm doing the same for a few other basic
things - the interrupt rate being one of those that helped spot problems
that otherwise would have gone unnoticed for a much longer period of
time).

Jan