title: no CPU usage recorded in Java Mission Control Flight Recorder
body: <p>Today I had a look at Mission Control introduced in Java 7 update 45 and tested a bit with Flight Recorder. Everything seems to be working as expected, I get a lot of data about threads, memory and whatever from the application I tested. Only one thing seems strange to me: In the category "General" there's no CPU usage shown, underneath the icon for the CPU usage there's only the sentence "No Events in Recording". When I don't use Flight Recording but the JMX Console, CPU usage is shown in the same application. During creation of the Flight Recording I left most of the settings as their default values, but made sure that on the page "Event Details for Profiling" "Operating System/Processor/CPU Load" is enabled and has a configured Period of 1000 ms, which should be enough to get some data using a test period of some minutes.</p>
  
  <p>Is there anything that I'm missing? Maybe a restriction due to performance reasons, something else I need to activate?</p>
  
  <p>Thanks for your suggestions!</p>