Understanding the Linux Kernel, Third Edition From I/O Ports to Process Management

"In order to thoroughly understand what makesLinux tick and why it works so well on a wide variety of systems, you need todelve deep into the heart of the kernel. The kernel handles all interactionsbetween the CPU and the external world, and determines which programs willshare processor time, in what order. It manages limited memory so well thathundreds of processes can share the system efficiently, and expertly organizesdata transfers so that the CPU isn't kept waiting any longer than absolutelynecessary for the relatively slow disks.