Nice post, Chris, and it's definitely a problem that many people are confused about (as the comments in this thread show). People who think the GIL is a proble

Nice post, Chris, and it's definitely a problem that many people are confused about (as the comments in this thread show). People who think the GIL is a problem either have no idea what they're talking about, or they really know what they're talking about. People who don't think the GIL is a problem either have no idea what they're talking about, or they really know what they're talking about. :-p One of the lesser-appreciated facts about the GIL is that it is an implementation detail of CPython. That is, it is entirely possible to implement a Python that does not have process-level globals and C statics. There is no structural reason why a C or C++ implementation of Python needs to have a GIL. It's just a legacy of the implementation that has stayed around for a long, long time. For instance, Trent Nelson has done some work to show that you can move to thread-local storage for the free lists and whatnot, and get nice multicore scaling, even with the existing CPython codebase[1]. There are still concurrency primitives that the language would need to offer at the C API level to manage the merger of these thread-local objects, but it's a whole lot better than only being able to use a single core in modern days. Fortunately I mostly get to work in the scientific field with (mostly) data parallel problems. [1] https://speakerdeck.com/trent/parallelizing-the-python-interpreter-an-alternate-approach-to-async https://speakerdeck.com/trent/parallelizing-the-python-inter...