Hey, thank you so much for all your hard work on psutil, it is my goto import!
And this looks like a really interesting development you have created to add to the available tools for detecting those tricky memory leaks.
I have done some work in this space as well such as how to write a Python C extension without leaks in the first place [0].
This also contains a section on memory leaks, using tools like your psutil [1]
This also shows where the Python documentation for C extensions contains errors, omissions or is misleading.
These errors can trap the unwary.
Also I developed a Python memory tracer, pymemtrace, that uses a variety of techniques (including using your psutil!) to track memory usage at different costs and levels of granularity [2].
Now psutil 7.2.0 is out I'll update both those projects.
Your C extension guide looks very useful and I quite like the foreword/history behind it. Have you considered updating the resource to account for the freethreaded mode (which will eventually become the default) on 3.14+?