Understanding the Linux Kernel (2nd Edition)

To thoroughly understand what makes Linux tick and why it's so efficient, you need to delve deep into the heart of the operating system—into the Linux kernel itself. The kernel is Linux—in the case of the Linux operating system, it's the only bit of software to which the term "Linux" applies. The kernel handles all the requests or completed I/O operations and determines which programs will share its processing time, and in what order. Responsible for the sophisticated memory management of the whole system, the Linux kernel is the force behind the legendary Linux efficiency. The new edition of Understanding the Linux Kernel takes you on a guided tour through the most significant data structures, many algorithms, and programming tricks used in the kernel. Probing beyond the superficial features, the authors offer valuable insights to people who want to know how things really work inside their machine. Relevant segments of code are dissected and discussed line by line. The book covers more than just the functioning of the code, it explains the theoretical underpinnings for why Linux does things the way it does. The new edition of the book has been updated to cover version 2.4 of the kernel, which is quite different from version 2.2: the virtual memory system is entirely new, support for multiprocessor systems is improved, and whole new classes of hardware devices have been added. The authors explore each new feature in detail. Other topics in the book include: Memory management including file buffering, process swapping, and Direct memory Access (DMA) The Virtual Filesystem and the Second Extended Filesystem Process creation and scheduling Signals, interrupts, and the essential interfaces to device drivers Timing Synchronization in the kernel Interprocess Communication (IPC) Program execution Understanding the Linux Kernel , Second Edition will acquaint you with all the inner workings of Linux, but is more than just an academic exercise. You'll learn what conditions bring out Linux's best performance, and you'll see how it meets the challenge of providing good system response during process scheduling, file access, and memory management in a wide variety of environments. If knowledge is power, then this book will help you make the most of your Linux system. In order to thoroughly understand what makes GNU/Linux tick, and why it works so well on a wide variety of systems, you need to delve deep into the heart of the operating system -- that is, into the Linux kernel itself. The kernel handles all the requests or completed I/O operations and determines which programs will share its processing time, and in what order. Responsible for the sophisticated management of the whole system, the Linux kernel is the force behind the legendary Linux efficiency. The new edition of Understanding the Linux Kernel takes you on a guided tour of the most significant data structures, algorithms, and programming tricks used in the kernel. Important Intel-specific features are discussed. But the book covers more than just the functioning of the code; it explains the theoretical underpinnings for why Linux does things the way it does. Understanding the Linux Kernel will acquaint you with all the inner workings of Linux, but it's not just an academic exercise. You'll learn what conditions bring out Linux's best performance, and you'll see how it meets the challenge of providing good system response during process scheduling, file access, and memory management in a wide variety of environments. Knowledge is power, and this book will help you make the most of your Linux system. Cover 1 Table of Contents 2 Copyright 6 Preface 7 Chapter 1 - Introduction 17 Chapter 2 - Memory Addressing 49 Chapter 3 - Processes 90 Chapter 4 - Interrupts and Exceptions 129 Chapter 5 - Kernel Synchronization 182 Chapter 6 - Timing Measurements 215 Chapter 7 - Merory Mangement 242 Chapter 8 - Process Address Space 285 Chapter 9 - System Calls 327 Chapter 10 - Signals 343 Chapter 11 - Process Scheduling 378 Chapter 12 - The Virtual Filesystem 400 Chapter 13 - Managing I/O Devices 466 Chapter 14 - Disk Caches 518 Chapter 15 - Accessing Files 542 Chapter 16 - Swapping: Methods for Freeing Memory 571 Chapter 17 - The Ext2 and Ext3 Filesystems 622 Chapter 18 - Networking 662 Chapter 19 - Process Communication 686 Chapter 20 - Program Execution 718 Appendix A - System Startup 744 Appendix B - Modules 753 Appendix C - Source Code Structure 765 Bibliography 773 Colophon 779 Index 780 This text allows the reader to understand when Linux performs best and how it meets the challenge of different environments that assign varying importance to the system's responsiveness in process scheduling, file access and memory management.