Byte Queue Limits: A Little-Known Networking Optimization Story
2025-01-16
This article recounts the story of Byte Queue Limits (BQL), a lesser-known networking optimization technique in the Linux kernel. BQL tackles bufferbloat by dynamically adjusting device queue limits, thereby reducing latency. The author, drawing on key concepts learned during their time at Sun Microsystems, details BQL's design philosophy, implementation, and algorithm, using diagrams and data to analyze its performance improvements and potential shortcomings. While newer hardware may eventually supersede BQL, its value for billions of low-end devices remains significant.