printk() - The Most Useful Tool is Now Showing its Age

Explore the evolution and challenges of printk(), the essential debugging tool for the Linux kernel, in this informative conference talk. Delve into the history and growth of printk(), examining its critical role in kernel debugging, from displaying the kernel banner at startup to showing the final message at shutdown. Understand how this versatile utility serves multiple, sometimes conflicting functionalities, and learn about the issues it faces in modern multi-CPU environments, including potential live locks. Gain insights into why printk() has become a source of concern for kernel developers and discover the complexities behind this seemingly simple yet crucial component of the Linux ecosystem.