On Mon, 2011-01-24 at 21:34 +0100, Frederic Weisbecker wrote:

But instead of a global tracing ABI number, I would rather suggest
one number per tracepoint subsystem (sched, power, etc...).

Ideally it would be per event, but sometimes those events tend to be
renamed or a whole tracepoint subsystem refactored (see workqueue
lately). Hence it might be better per subsystem. 

What's wrong with what we have? the /format file is pretty unique to
function as a version number of you use a hash over it.