Pyflame: A Ptracing Profiler For Python

(This project is deprecated and not maintained.)

Pyflame is a high performance profiling tool that generates flame graphs for Python. Pyflame is implemented in C++, and uses the Linux ptrace(2) system call to collect profiling information. It can take snapshots of the Python call stack without explicit instrumentation, meaning you can profile a program without modifying its source code. Pyflame is capable of profiling embedded Python interpreters like uWSGI. It fully supports profiling multi-threaded Python programs.

Pyflame usually introduces significantly less overhead than the builtin

profile

cProfile

Full Documentation: https://pyflame.readthedocs.io

Quickstart

Building And Installing

For Debian/Ubuntu, install the following:

# Install build dependencies on Debian or Ubuntu.
sudo apt-get install autoconf automake autotools-dev g++ pkg-config python-dev python3-dev libtool make

Once you have the build dependencies installed:

./autogen.sh
./configure
make

The

make

src/pyflame

Optionally, if you have

virtualenv

make check

Using Pyflame

The full documentation for using Pyflame is here. But here's a quick guide:

# Attach to PID 12345 and profile it for 1 second
pyflame -p 12345

Attach to PID 768 and profile it for 5 seconds, sampling every 0.01 seconds
pyflame -s 5 -r 0.01 -p 768
Run py.test against tests/, emitting sample data to prof.txt
pyflame -o prof.txt -t py.test tests/

In all of these cases you will get flame graph data on stdout (or to a file if you used

-o

flamegraph.pl

FAQ

The full FAQ is here.

What's The Deal With (idle) Time?

Full answer here. tl;dr: use the

-x

What About These Ptrace Errors?

See here.

How Do I Profile Threaded Applications?

Use the

--threads

Is There A Way To Just Dump Stack Traces?

Yes, use the

-d