PERFORCE change 132685 for review

[John Birrell]

http://perforce.freebsd.org/chv.cgi?CH=132685

Change 132685 by jb at jb_freebsd1 on 2008/01/07 07:45:23

	Add a DTrace-debug-specific printf function that can be called in a
	probe context with all Function Boundary Trace (fbt) probes enabled.
	The function uses per-cpu circular buffers and is very careful not
	to call any functions outside the dtrace module while buffering.
	
	The output function will be called from dtrace's deadman cyclic
	callback function.

Affected files ...

.. //depot/projects/dtrace/src/sys/cddl/dev/dtrace/dtrace_debug.c#1 add

Differences ...