How to monitor thread scheduling and the criticality of tasks?

Hi L4 hackers,

How can you monitor how threads are scheduled for execution in L4Re?
The trace buffer does not seem to offer information about the
criticality of tasks.
The l4re-snapshot-2014092821, however, refers to a monitoring framework
named "ferret" in  /obj/l4linux/ux/source/arch/l4/Kconfig but does not
provide its source code.
Is ferret publicly available?
Do you know of any alternatives?

Thanks and regards,
Karl