DTrace FBT provider heads-up

[Darran Hunt <darran%NetBSD.org@localhost>]

Hi all,

I've committed the Function Boundary Trace provider to NetBSD  
current.  This DTrace provider automatically instruments every  
function in the kernel with an entry and exit probe.  The probes have  
true zero-probe effect (i.e. they don't affect the system when  
disabled), as they don't actually exist in the code until they're  
enabled.  When enabled a probe directly patches the function to add a  
jump into FBT provider at the function's entry or exit points.

This gives us over 29,000 instrumentation points available for tracing  
with DTrace.  The full argument list is passed to the probe on  
function entry, and the return result is passed on exit.

More info available here: 
http://docs.sun.com/app/docs/doc/817-6223/chp-fbt?a=view

Regards,
Darran.