为了彻底理解是什么使得Linux能正常运行以及其为何能在各种不同的系统中运行良好，你需要深入研究内核最本质的部分。内核处理CPU与外界间的所有交互，并且决定哪些程序将以什么顺序共享处理器时间。它如此有效地管理有限的内存，以至成百上千的进程能高效地共享系统。它熟练地统筹数据传输，这样CPU不用为等待速度相对较慢的硬盘而消耗比正常耗时更长的时间。

《深入理解Linux内核，第三版》指导你对内核中使用的最重要的数据结构、算法和程序设计诀窍进行一次遍历。通过对表面特性的探究，作者给那些想知道自己机器工作原理的人提供了颇有价值的见解。书中讨论了Intel特有的重要性质。相关的代码片段被逐行剖析。然而，本书涵盖的不仅仅是代码的功能，它解释了Linux以自己的方式工作的理论基础。

为了彻底理解是什么使得Linux能正常运行以及其为何能在各种不同的系统中运行良好，你需要深入研究内核最本质的部分。内核处理CPU与外界间的所有交互，并且决定哪些程序将以什么顺序共享处理器时间。它如此有效地管理有限的内存，以至成百上千的进程能高效地共享系统。它熟练地统筹数据传输，这样CPU不用为等待速度相对较慢的硬盘而消耗比正常耗时更长的时间。

《深入理解Linux内核，第三版》指导你对内核中使用的最重要的数据结构、算法和程序设计诀窍进行一次遍历。通过对表面特性的探究，作者给那些想知道自己机器工作原理的人提供了颇有价值的见解。书中讨论了Intel特有的重要性质。相关的代码片段被逐行剖析。然而，本书涵盖的不仅仅是代码的功能，它解释了Linux以自己的方式工作的理论基础。

本书新版涵盖2.6版本，其在内核的几乎每个子系统中都有重要的变化，尤其是在内存管理和块设备领域。本书侧重于以下主题：

·内存管理，包括文件缓存、进程交换和直接内存存取（DMA）

·虚拟文件系统层和第二、第三扩展文件系统

·进程创建和调度

·信号、中断和设备驱动程序的主要接口

·定时

·内核中的同步

·进程间通信（IPC）

·程序的执行

《深入理解Linux内核》将使你了解Linux的所有内部工作，它不仅仅是一个理论上的练习。你将学习到哪些情况下Linux性能最佳，并且你将看到，在大量的不同环境里进行进程调度、文件存取和内存管理时，它如何满足提供良好的系统响应的需要。这本书将帮助你充分利用Linux系统。

Preface

The Audience for This Book

Organization of the Material

Level of Description

Overview of the Book

Background Information

Conventions in This Book

How to Contact Us

Safari? Enabled

Acknowledgments

Chapter 1. Introduction

Section 1.1. Linux Versus Other Unix-Like Kernels

Section 1.2. Hardware Dependency

Section 1.3. Linux Versions

Section 1.4. Basic Operating System Concepts

Section 1.5. An Overview of the Unix Filesystem

Section 1.6. An Overview of Unix Kernels

Chapter 2. Memory Addressing

Section 2.1. Memory Addresses

Section 2.2. Segmentation in Hardware

Section 2.3. Segmentation in Linux

Section 2.4. Paging in Hardware

Section 2.5. Paging in Linux

Chapter 3. Processes

Section 3.1. Processes, Lightweight Processes, and Threads

Section 3.2. Process Descriptor

Section 3.3. Process Switch

Section 3.4. Creating Processes

Section 3.5. Destroying Processes

Chapter 4. Interrupts and Exceptions

Section 4.1. The Role of Interrupt Signals

Section 4.2. Interrupts and Exceptions

Section 4.3. Nested Execution of Exception and Interrupt Handlers

Section 4.4. Initializing the Interrupt Descriptor Table

Section 4.5. Exception Handling

Section 4.6. Interrupt Handling

Section 4.7. Softirqs and Tasklets

Section 4.8. Work Queues

Section 4.9. Returning from Interrupts and Exceptions

Chapter 5. Kernel Synchronization

Section 5.1. How the Kernel Services Requests

Section 5.2. Synchronization Primitives

Section 5.3. Synchronizing Accesses to Kernel Data Structures

Section 5.4. Examples of Race Condition Prevention

Chapter 6. Timing Measurements

Section 6.1. Clock and Timer Circuits

Section 6.2. The Linux Timekeeping Architecture

Section 6.3. Updating the Time and Date

Section 6.4. Updating System Statistics

Section 6.5. Software Timers and Delay Functions

Section 6.6. System Calls Related to Timing Measurements

Chapter 7. Process Scheduling

Section 7.1. Scheduling Policy

Section 7.2. The Scheduling Algorithm

Section 7.3. Data Structures Used by the Scheduler

Section 7.4. Functions Used by the Scheduler

Section 7.5. Runqueue Balancing in Multiprocessor Systems

Section 7.6. System Calls Related to Scheduling

Chapter 8. Memory Management

Section 8.1. Page Frame Management

Section 8.2. Memory Area Management

Section 8.3. Noncontiguous Memory Area Management

Chapter 9. Process Address Space

Section 9.1. The Process's Address Space

Section 9.2. The Memory Descriptor

Section 9.3. Memory Regions

Section 9.4. Page Fault Exception Handler

Section 9.5. Creating and Deleting a Process Address Space

Section 9.6. Managing the Heap

Chapter 10. System Calls

Section 10.1. POSIX APIs and System Calls

Section 10.2. System Call Handler and Service Routines

Section 10.3. Entering and Exiting a System Call

Section 10.4. Parameter Passing

Section 10.5. Kernel Wrapper Routines

Chapter 11. Signals

Section 11.1. The Role of Signals

Section 11.2. Generating a Signal

Section 11.3. Delivering a Signal

Section 11.4. System Calls Related to Signal Handling

Chapter 12. The Virtual Filesystem

Section 12.1. The Role of the Virtual Filesystem (VFS)

Section 12.2. VFS Data Structures

Section 12.3. Filesystem Types

Section 12.4. Filesystem Handling

Section 12.5. Pathname Lookup

Section 12.6. Implementations of VFS System Calls

Section 12.7. File Locking

Chapter 13. I/O Architecture and Device Drivers

Section 13.1. I/O Architecture

Section 13.2. The Device Driver Model

Section 13.3. Device Files

Section 13.4. Device Drivers

Section 13.5. Character Device Drivers

Chapter 14. Block Device Drivers

Section 14.1. Block Devices Handling

Section 14.2. The Generic Block Layer

Section 14.3. The I/O Scheduler

Section 14.4. Block Device Drivers

Section 14.5. Opening a Block Device File

Chapter 15. The Page Cache

Section 15.1. The Page Cache

Section 15.2. Storing Blocks in the Page Cache

Section 15.3. Writing Dirty Pages to Disk

Section 15.4. The sync( ), fsync( ), and fdatasync( ) System Calls

Chapter 16. Accessing Files

Section 16.1. Reading and Writing a File

Section 16.2. Memory Mapping

Section 16.3. Direct I/O Transfers

Section 16.4. Asynchronous I/O

Chapter 17. Page Frame Reclaiming

Section 17.1. The Page Frame Reclaiming Algorithm

Section 17.2. Reverse Mapping

Section 17.3. Implementing the PFRA

Section 17.4. Swapping

Chapter 18. The Ext2 and Ext3 Filesystems

Section 18.1. General Characteristics of Ext2

Section 18.2. Ext2 Disk Data Structures

Section 18.3. Ext2 Memory Data Structures

Section 18.4. Creating the Ext2 Filesystem

Section 18.5. Ext2 Methods

Section 18.6. Managing Ext2 Disk Space

Section 18.7. The Ext3 Filesystem

Chapter 19. Process Communication

Section 19.1. Pipes

Section 19.2. FIFOs

Section 19.3. System V IPC

Section 19.4. POSIX Message Queues

Chapter 20. Program ExZecution

Section 20.1. Executable Files

Section 20.2. Executable Formats

Section 20.3. Execution Domains

Section 20.4. The exec Functions

Appendix A. System Startup

Section A.1. Prehistoric Age: the BIOS

Section A.2. Ancient Age: the Boot Loader

Section A.3. Middle Ages: the setup( ) Function

Section A.4. Renaissance: the startup_32( ) Functions

Section A.5. Modern Age: the start_kernel( ) Function

Appendix B. Modules

Section B.1. To Be (a Module) or Not to Be?

Section B.2. Module Implementation

Section B.3. Linking and Unlinking Modules

Section B.4. Linking Modules on Demand

Bibliography

Books on Unix Kernels

Books on the Linux Kernel

Books on PC Architecture and Technical Manuals on Intel Microprocessors

Other Online Documentation Sources

Research Papers Related to Linux Development

About the Authors

Colophon

Index