py_flowinfo.d - snoop Python function flow with info using DTrace. py_flowinfo.d This traces activity from all Python programs on the system that are running with Python provider support. Filename and function names are printed if available. Any Evolving - uses the DTrace Python provider, which may change as additional features are introduced. Check Python/Readme to see what version these scripts are based on.

Default output, # py_flowinfo.d

C CPU-id

PID Process ID

DELTA(us) Elapsed time from previous line to this line

FILE Filename of the Python program

LINE Line number of filename

TYPE Type of call (func)

FUNC Python function

-> function entry

<- function return

Watch the first column carefully, it prints the CPU-id. If it changes, then it is very likely that the output has been shuffled.

See the DTraceToolkit for further documentation under the Examples, Notes and Docs directories. The example files may be especially useful as they aim to demonstrate how to interpret the output. py_flowinfo.d will run until Ctrl-C is hit. Brendan Gregg [CA, USA] dtrace(1M)