Deepin Linux

Nov 27, 2025 · Backend Development

How epoll Scales to Millions of Connections Using Red‑Black Trees and Ready Lists

This article explains the inner workings of Linux's epoll mechanism, detailing how red‑black trees manage registered file descriptors and how a ready‑list delivers events in O(1) time, covering core APIs, data structures, insertion‑deletion logic, and the full kernel‑space to user‑space flow.