Epoll and Kqueue: How Operating Systems Learned to Wait Efficiently
Modern operating systems use event‑notification mechanisms such as Linux’s epoll and BSD’s kqueue to replace inefficient polling loops. These interfaces allow applications to register interest in file‑descriptor events and receive notifications only when activity occurs, reducing CPU usage and latency. The article traces their development, compares design choices, and explains why they are essential for high‑performance networking and I/O‑bound workloads.