py_flow.d - snoop Python execution showing function flow. py_flow.d This traces Python activity from all Python programs on the system running with Python provider support. This watches Python function entries and returns, and indents child function calls. 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_flow.d

C CPU-id

TIME(us) Time since boot, us

FILE Filename that this function belongs to

FUNC Function name

-> 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_flow.d will run until Ctrl-C is hit. Brendan Gregg [CA, USA] dtrace(1M)