Book Image

Mastering Linux Kernel Development

By : CH Raghav Maruthi
Book Image

Mastering Linux Kernel Development

By: CH Raghav Maruthi

Overview of this book

Mastering Linux Kernel Development looks at the Linux kernel, its internal arrangement and design, and various core subsystems, helping you to gain significant understanding of this open source marvel. You will look at how the Linux kernel, which possesses a kind of collective intelligence thanks to its scores of contributors, remains so elegant owing to its great design. This book also looks at all the key kernel code, core data structures, functions, and macros, giving you a comprehensive foundation of the implementation details of the kernel’s core services and mechanisms. You will also look at the Linux kernel as well-designed software, which gives us insights into software design in general that are easily scalable yet fundamentally strong and safe. By the end of this book, you will have considerable understanding of and appreciation for the Linux kernel.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Introducing exclusion locks


Hardware-specific atomic instructions can operate only on CPU word- and doubleword-size data; they cannot be directly applied on shared data structures of custom size. For most multi-threaded scenarios, often it can be observed that shared data is of custom sizes, for example, a structure with n elements of various types. Concurrent code paths accessing such data usually comprise a bunch of instructions that are programmed to access and manipulate shared data; such access operations must be executed atomically to prevent races. To ensure atomicity of such code blocks, mutual exclusion locks are used. All multi-threading environments provide implementation of exclusion locks that are based on exclusion protocols. These locking implementations are built on top of hardware-specific atomic instructions.

The Linux kernel implements operation interfaces for standard exclusion mechanisms such as mutual and reader-writer exclusions. It also contains support for various...