FunctionTrace - Low overhead Python Profiler

[Thomas Passin]

I stumbled upon an interesting profiler today - FunctionTrace.  It works together with Firefox so as to make use of Firefox's profiling UI, and supposedly incurs almost no slowdown while profiling.  It's currently Linux.Mac only.

FunctionTrace Home Page

Building FunctionTrace, a graphical Python profiler

I've never done any Python profiling, but this looks worth looking at, especially the second link.

[Edward K. Ream]

On Saturday, November 5, 2022 at 9:16:56 AM UTC-5 tbp1...@gmail.com wrote:

I stumbled upon an interesting profiler today - FunctionTrace.  It works together with Firefox so as to make use of Firefox's profiling UI, and supposedly incurs almost no slowdown while profiling.  It's currently Linux.Mac only.

FunctionTrace Home Page

Building FunctionTrace, a graphical Python profiler

Thanks for these links. The sources are here.

Edward

[Edward K. Ream]

> The sources [for FunctionTrace] are here.

FunctionTrace is likely a python wrapper around system tracing tools. Surely there is no way to get the performance claimed using only python (or rust).

Edward

[Jacob MacDonald]

It looks to be a C extension module
(https://gitlab.com/mbryant/functiontrace/-/blob/770340083a06b46c6dfe6cd8128600a11a47d3dc/py-functiontrace/_functiontrace.c)
which uses profiling hooks built into Python
(https://docs.python.org/3/c-api/init.html#c.PyEval_SetProfile, among
others).

[Edward K. Ream]

On Monday, November 7, 2022 at 9:17:25 AM UTC-6 jacc...@gmail.com wrote:

It looks to be a C extension module which uses profiling hooks built into Python

Thanks for your comments. As I read/skim the code, the magic must be elsewhere, that it, in the code that calls the callbacks. Imo, that code must be very low level (system/compiler dependent) code. But of course I could be mistaken.

Many years ago there was a unix tool called (iirc) systrace. That tool might have evolved into the Android systrace tool, but if so it has evolved considerably.

Edward