The most complete, authoritative technical guide to the FreeBSD kernel’s internal structure has now been extensively updated to cover all major improvements between Versions 5 and 11. Approximately one-third of this edition’s content is completely new, and another one-third has been extensively rewritten.

Three long-time FreeBSD project leaders begin with a concise overview of the FreeBSD kernel’s current design and implementation. Next, they cover the FreeBSD kernel from the system-call level down–from the interface to the kernel to the hardware. Explaining key design decisions, they detail the concepts, data structures, and algorithms used in implementing each significant system facility, including process management, security, virtual memory, the I/O system, filesystems, socket IPC, and networking.

This Second Edition

• Explains highly scalable and lightweight virtualization using FreeBSD jails, and virtual-machine acceleration with Xen and Virtio device paravirtualization

• Describes new security features such as Capsicum sandboxing and GELI cryptographic disk protection

• Fully covers NFSv4 and Open Solaris ZFS support

• Introduces FreeBSD’s enhanced volume management and new journaled soft updates

• Explains DTrace’s fine-grained process debugging/profiling

• Reflects major improvements to networking, wireless, and USB support

Readers can use this guide as both a working reference and an in-depth study of a leading contemporary, portable, open source operating system. Technical and sales support professionals will discover both FreeBSD’s capabilities and its limitations. Applications developers will learn how to effectively and efficiently interface with it; system administrators will learn how to maintain, tune, and configure it; and systems programmers will learn how to extend, enhance, and interface with it.

Marshall Kirk McKusick writes, consults, and teaches classes on UNIX- and BSD-related subjects. While at the University of California, Berkeley, he implemented the 4.2BSD fast filesystem. He was research computer scientist at the Berkeley Computer Systems Research Group (CSRG), overseeing development and release of 4.3BSD and 4.4BSD. He is a FreeBSD Foundation board member and a long-time FreeBSD committer. Twice president of the Usenix Association, he is also a member of ACM, IEEE, and AAAS.

George V. Neville-Neil hacks, writes, teaches, and consults on security, networking, and operating systems. A FreeBSD Foundation board member, he served on the FreeBSD Core Team for four years. Since 2004, he has written the “Kode Vicious” column for Queue and Communications of the ACM. He is vice chair of ACM’s Practitioner Board and a member of Usenix Association, ACM, IEEE, and AAAS.

Robert N.M. Watson is a University Lecturer in systems, security, and architecture in the Security Research Group at the University of Cambridge Computer Laboratory. He supervises advanced research in computer architecture, compilers, program analysis, operating systems, networking, and security. A FreeBSD Foundation board member, he served on the Core Team for ten years and has been a committer for fifteen years. He is a member of Usenix Association and ACM.

这本关于FreeBSD内核内部结构的最完整、最权威的技术指南，现在已经进行了广泛的更新，以涵盖第5版和第11版之间的所有主要改进。本版约有三分之一的内容是全新的，另有三分之一的内容是经过广泛的重写的。

三位长期从事FreeBSD项目的领导人首先对FreeBSD内核目前的设计和实现做了一个简明的概述。接下来，他们介绍了FreeBSD内核从系统调用层面到硬件的接口。在解释了关键的设计决策之后，他们详细介绍了在实现每个重要的系统设施时使用的概念、数据结构和算法，包括进程管理、安全、虚拟内存、I/O 系统、文件系统、套接字 IPC 和网络。

本书第二版

- 解释了使用FreeBSD jails的高度可扩展和轻量级的虚拟化，以及使用Xen和Virtio设备准虚拟化的虚拟机加速功能

- 描述了新的安全特性，如Capsicum沙箱和GELI加密磁盘保护

- 全面介绍NFSv4和Open Solaris ZFS支持

- 介绍了 FreeBSD 增强的卷管理和新的日志式软更新

- 解释了 DTrace 的细粒度进程调试/剖析功能

- 反映了对网络、无线和 USB 支持的重大改进

读者可以将本指南作为工作参考，并深入研究一个领先的当代、可移植的开源操作系统。技术和销售支持人员将发现 FreeBSD 的能力和它的局限性。应用程序开发人员将学习如何有效地与之对接；系统管理员将学习如何维护、调整和配置它；而系统程序员将学习如何扩展、增强和与之对接。

马歇尔-柯克-麦库锡克（Marshall Kirk McKusick）在UNIX和BSD相关科目上进行写作、咨询和授课。在加利福尼亚大学伯克利分校时，他实现了4.2BSD快速文件系统。他是伯克利计算机系统研究小组(CSRG)的研究计算机科学家，负责监督4.3BSD和4.4BSD的开发和发布。他是FreeBSD基金会的董事会成员，也是FreeBSD的长期投入者。两次担任Usenix协会的主席，他也是ACM、IEEE和AAAS的成员。

George V. Neville-Neil 在安全、网络和操作系统方面从事黑客活动、写作、教学和咨询。作为FreeBSD基金会的董事会成员，他曾在FreeBSD核心团队任职四年。自2004年以来，他为ACM的Queue和通讯撰写了 "Kode Vicious "专栏。他是ACM实践者委员会的副主席，也是Usenix协会、ACM、IEEE和AAAS的成员。

Robert N.M. Watson是剑桥大学计算机实验室安全研究小组的系统、安全和架构方面的大学讲师。他负责指导计算机结构、编译器、程序分析、操作系统、网络和安全方面的高级研究。作为FreeBSD基金会的董事会成员，他在核心团队中服务了十年，并担任了十五年的承诺人。他是Usenix协会和ACM的成员。