Operating System Concepts Essentials, Second Edition

The Linux System

Updated by Robert Love

This chapter presents an in-depth examination of the Linux operating system. By examining a complete, real system, we can see how the concepts we have discussed relate both to one another and to practice.

Linux is a variant of UNIX that has gained popularity over the last several decades, powering devices as small as mobile phones and as large as roomfilling supercomputers. In this chapter, we look at the history and development of Linux and cover the user and programmer interfaces that Linux presents—interfaces that owe a great deal to the UNIX tradition. We also discuss the design and implementation of these interfaces. Linux is a rapidly evolving operating system. This chapter describes developments through the Linux 3.2 kernel, which was released in 2012.

CHAPTER OBJECTIVES

• To explore the history of the UNIX operating system from which Linux is derived and the principles upon which Linux's design is based.
• To examine the Linux process model and illustrate how Linux schedules processes and provides interprocess communication.
• To look at memory management in Linux.
• To explore how Linux implements file systems and manages I/O devices.

15.1 Linux History

Linux looks and feels much like any other UNIX system; indeed, UNIX compatibility has been a major design goal of the Linux project. However, Linux is much younger than most UNIX systems. ...