[PATCH RFC idle 2/3] arm: Avoid invoking RCU when CPU is idle

[Steven Rostedt]

On Fri, 2012-02-03 at 11:40 -0800, Paul E. McKenney wrote:

> So the idea is that if you have a trace event that is to be used in idle,
> you use TRACE_EVENT_IDLE() rather than TRACE_EVENT() to declare that
> trace event?  That would work for me, and might make for fewer changes
> for the architecture guys.  Also, this should address the code-size
> concerns we discussed yesterday.
> 
> So sounds good!
> 
> Is a DEFINE_EVENT_IDLE() also needed?  Or prehaps a
> DECLARE_EVENT_CLASS_IDLE()?  My guess is "yes" for at least one of the
> two based on include/trace/events/power.h.

I'll have to take a look. I may even find a better way to do this too.

> 
> I will keep RCU_NONIDLE() for at least a little while (reworking comments
> to point out TRACE_EVENT_IDLE() and friends) in case there turn out to
> be non-tracepoint uses of RCU in the idle loop.

OK, I'll take a crack at this next Monday.

-- Steve