Resource governour, howto see/proof setup is working ?

Hi all,
I have a SQL 2008 R2 server with 20 databases in one instance.
Users in one of those db's are causing somtimes high cpu usage and I want to avoid that.

So I set up resource governour with a new workload group, ressource pool (max cpu 10 %)  and classifier function to assign users with default db  (LOGINPROPERTY(suser_name(), 'DefaultDatabasse') = 'MyDB') to the newly created workload group.

My problem now is how can I proof/see that my setup is working ??

When I run a high cpu load as a user with default db 'MyDB' it goes to 100 % cpu (because sql server wont stop the solo runner).
If I generate the same load as a non 'MyDB' user the cpu goes to 100 % as well and if I start the same load again as 'MyDB' user the load stays at 100 % of course.
How can I see that the resource governour is kicking in and limiting my 'MyDB' user's load to 10 % ??

Any help is highly appreciated.
TIA
acki4711