From Python 3.3 to today: ending 15 years of subprocess polling
Summary
The article explains why busy-wait polling for subprocess termination is inefficient and presents an event-driven alternative using pidfd_open with poll/epoll on Linux, and kqueue on macOS/BSD, with Windows leveraging WaitForSingleObject. It contrasts Linux/macOS approaches, discusses graceful fallbacks, and shares measurable CPU-efficiency improvements and upstream contributions to CPython and psutil.