o	What is RCU?  Overview, block diagram.
	o	RCU read-side critical sections.
	o	RCU quiescent states (momentary and extended).
	o	RCU grace periods.
	o	RCU idleness (no grace period in progress)
	Why preemptible RCU?  History, including isolcpus monastery approach.
	Why keep RCU-sched if there is preemptible RCU?
	Why RCU-bh?
	Why SRCU?
	Why workqueue RCU?
	Note: these articles not only contain trick questions, they
	contain more than a few trick answers.  My goal in writing
	this was to find bugs in RCU, and you are less likely to
	be able to do this if you aren't thinking on your feet.  And
	there is nothing quite like a few trick questions and answers
	to help you think on your feet!

What is RCU?
o	Materials from LWN series and from SRCU LWN article.

RCU as state machine, inputs and outputs:
Inputs:
o	Explicit quiescent states
o	Dyntick-idle transitions
o	CPU-hotplug events
o	Scheduling-clock interrupts
o	Requests for grace periods: normal (sync/async), expedited
Outputs:
o	Grace periods (awaken waiters, invoke callbacks)
o	Control dyntick-idle entry
Configuration:
o	NR_CPUS, 64BIT, ...
