Understanding The Linux Kernel

by Bovet, Daniel Plerre

• ISBN13: 9780596005658
• ISBN10: 0596005652
• Edition: 3rd
• Format: Paperback
• Copyright: 2005-11-01
• Publisher: Oreilly & Associates Inc

Summary

This new edition covers Version 2.6 of the Linux kernel, which has seen significant changes to nearly every kernel subsystem, particularly in the areas of memory management and block devices. Understanding the Linux Kernel provides a guided tour of the code that forms the core of all Linux operating systems. Beyond the functioning of the code, the book explains the theoretical underpinnings for why Linux, and many other operating systems, do things the way they do.

Author Biography

Daniel P. Bovet got a Ph.D. in computer science at UCLA in 1968 and is now full Professor at the University of Rome, "Tor Vergata," Italy. He had to wait over 25 years before being able to teach an operating system course in a proper manner because of the lack of source code for modern, well-designed systems. Now, thanks to cheap PCs and to Linux, Marco and Dan are able to cover all the facets of an operating system from booting to tuning and are able to hand out tough, satisfying homework to their students. (These young guys working at home on their PCs are really spoiled; they never had to fight with punched cards.) In fact, Dan was so fascinated by the accomplishments of Linus Torvalds and his followers that he spent the last few years trying to unravel some of Linux's mysteries. It seemed natural, after all that work, to write a book about what he found.

Marco Cesati received a degree in mathematics in 1992 and a Ph.D. in computer science (University of Rome, "La Sapienza") in 1995. He is now a research assistant in the computer science department of the School of Engineering (University of Rome, "Tor Vergata"). In the past, he served as system administrator and Unix programmer for the university (as a Ph.D. student) and for several institutions (as a consultant).

Table of Contents

Preface	xi
Introduction	1	(34)
Linux Versus Other Unix-Like Kernels	2	(4)
Hardware Dependency	6	(1)
Linux Versions	7	(1)
Basic Operating System Concepts	8	(4)
An Overview of the Unix Filesystem	12	(7)
An Overview of Unix Kernels	19	(16)
Memory Addressing	35	(44)
Memory Addresses	35	(1)
Segmentation in Hardware	36	(5)
Segmentation in Linux	41	(4)
Paging in Hardware	45	(12)
Paging in Linux	57	(22)
Processes	79	(52)
Processes, Lightweight Processes, and Threads	79	(2)
Process Descriptor	81	(21)
Process Switch	102	(12)
Creating Processes	114	(12)
Destroying Processes	126	(5)
Interrupts and Exceptions	131	(58)
The Role of Interrupt Signals	132	(1)
Interrupts and Exceptions	133	(10)
Nested Execution of Exception and Interrupt Handlers	143	(2)
Initializing the Interrupt Descriptor Table	145	(3)
Exception Handling	148	(3)
Interrupt Handling	151	(20)
Softirqs and Tasklets	171	(9)
Work Queues	180	(3)
Returning from Interrupts and Exceptions	183	(6)
Kernel Synchronization	189	(38)
How the Kernel Services Requests	189	(5)
Synchronization Primitives	194	(23)
Synchronizing Accesses to Kernel Data Structures	217	(5)
Examples of Race Condition Prevention	222	(5)
Timing Measurements	227	(31)
Clock and Timer Circuits	228	(4)
The Linux Timekeeping Architecture	232	(8)
Updating the Time and Date	240	(1)
Updating System Statistics	241	(3)
Software Timers and Delay Functions	244	(8)
System Calls Related to Timing Measurements	252	(6)
Process Scheduling	258	(36)
Scheduling Policy	258	(4)
The Scheduling Algorithm	262	(4)
Data Structures Used by the Scheduler	266	(4)
Functions Used by the Scheduler	270	(14)
Runqueue Balancing in Multiprocessor Systems	284	(6)
System Calls Related to Scheduling	290	(4)
Memory Management	294	(57)
Page Frame Management	294	(29)
Memory Area Management	323	(19)
Noncontiguous Memory Area Management	342	(9)
Process Address Space	351	(47)
The Process's Address Space	352	(1)
The Memory Descriptor	353	(4)
Memory Regions	357	(19)
Page Fault Exception Handler	376	(16)
Creating and Deleting a Process Address Space	392	(3)
Managing the Heap	395	(3)
System Calls	398	(22)
POSIX APIs and System Calls	398	(1)
System Call Handler and Service Routines	399	(2)
Entering and Exiting a System Call	401	(8)
Parameter Passing	409	(9)
Kernel Wrapper Routines	418	(2)
Signals	420	(36)
The Role of Signals	420	(13)
Generating a Signal	433	(6)
Delivering a Signal	439	(11)
System Calls Related to Signal Handling	450	(6)
The Virtual Filesystem	456	(63)
The Role of the Virtual Filesystem (VFS)	456	(6)
VFS Data Structures	462	(19)
Filesystem Types	481	(2)
Filesystem Handling	483	(12)
Pathname Lookup	495	(10)
Implementations of VFS System Calls	505	(5)
File Locking	510	(9)
I/O Architecture and Device Drivers	519	(41)
I/O Architecture	519	(7)
The Device Driver Model	526	(10)
Device Files	536	(4)
Device Drivers	540	(12)
Character Device Drivers	552	(8)
Block Device Drivers	560	(39)
Block Devices Handling	560	(6)
The Generic Block Layer	566	(6)
The I/O Scheduler	572	(13)
Block Device Drivers	585	(10)
Opening a Block Device File	595	(4)
The Page Cache	599	(32)
The Page Cache	600	(11)
Storing Blocks in the Page Cache	611	(11)
Writing Dirty Pages to Disk	622	(7)
The sync( ), fsync( ), and fdatasync( ) System Calls	629	(2)
Accessing Files	631	(45)
Reading and Writing a File	632	(25)
Memory Mapping	657	(11)
Direct I/O Transfers	668	(3)
Asynchronous I/O	671	(5)
Page Frame Reclaiming	676	(62)
The Page Frame Reclaiming Algorithm	676	(4)
Reverse Mapping	680	(9)
Implementing the PFRA	689	(23)
Swapping	712	(26)
The Ext2 and Ext3 Filesystems	738	(37)
General Characteristics of Ext2	738	(3)
Ext2 Disk Data Structures	741	(9)
Ext2 Memory Data Structures	750	(3)
Creating the Ext2 Filesystem	753	(2)
Ext2 Methods	755	(2)
Managing Ext2 Disk Space	757	(9)
The Ext3 Filesystem	766	(9)
Process Communication	775	(33)
Pipes	776	(11)
FIFOs	787	(2)
System V IPC	789	(17)
POSIX Message Queues	806	(2)
Program Execution	808	(27)
Executable Files	809	(15)
Executable Formats	824	(3)
Execution Domains	827	(1)
The exec Functions	828	(7)
A. System Startup	835	(7)
B. Modules	842	(10)
Bibliography	852	(5)
Source Code Index	857	(48)
Index	905