SOLARIS INTERNALS Core Kernel Components i SOLARIS INTERNALS Core Kernel Components Jim Mauro and Richard McDougall Sun Microsystems Press A Prentice Hall Title © 2000 Sun Microsystems, Inc — Printed in the United States of America 901 San Antonio Road, Palo Alto, California 94303 U.S.A All rights reserved This product and related documentation are protected by copyright and distributed under licenses restricting its use, copying, distribution and decompilation No part of this product or related documentation may be reproduced in any form by any means without prior written authorization of Sun and its licensors, if any RESTRICTED RIGHTS LEGEND: Use, duplication, or disclosure by the United States Government is subject to the restrictions as set forth in DFARS 252.227-7013 (c)(1)(ii) and FAR 52.227-19 The product described in this manual may be protected by one or more U.S patents, foreign patents, or pending applications TRADEMARKS—Sun, Sun Microsystems, the Sun logo, HotJava, Solaris, SunExpress, SunScreen, SunDocs, SPARC, SunOS, and SunSoft are trademarks or registered trademarks of Sun Microsystems, Inc All other products or services mentioned in this book are the trademarks or service marks of their respective companies or organizations 10 ISBN 0-13-022496-0 Sun Microsystems Press A Prentice Hall Title For Traci for your love and encouragement Richard For Donna, Frankie and Dominick All my love, always Jim ACKNOWLEDGEMENTS It ‘s hard to thank all people that helped us with this book As a minimum, we owe: • Thanks to Brian Wong, Adrian Cockcroft, Paul Strong, Lisa Musgrave and Fraser Gardiner for all your help and advise for the structure and content of this book • Thanks to Tony Shoumack, Phil Harman, Jim Moore, Robert Miller, Martin Braid, Robert Lane, Bert Beals, Magnus Bergman, Calum Mackay, Allan Packer, Magnus Bergman, Chris Larson, Bill Walker, Keith Bierman, Dan Mick and Raghunath Shenbagam for helping to review the material • A very special thanks to David Collier-Brown, Norm Shulman, Dominic Kay, Jarod Jenson, Bob Sneed, and Evert Hoogendoorn for painstaking page by page reviews of the whole book • Our thanks to the engineers in the Solaris business unit - Jim Litchfield, Michael Shapiro, Jeff Bonwick, Wolfgang Thaler, Bryan Cantrill, Roger Faulker, Andy Tucker, Casper Dik, Tim Marsland, Andy Rudoff, Greg Onufer, Rob Gingell, Devang Shah, Deepankar Das, Dan Price and Kit Chow for their advise and guidance We’re quite sure there are others, and we apologize up front to those whose names we have missed • Thank you to the systems engineers and technical support staff at Sun for the corrections and suggestions along the way • Thanks to Lou Marchant - for the endless search for engine pictures, and Dwayne Schumate at Lotus Cars USA for coordinating permission to use the images of the Lotus V8 engine • Thanks to the folks at Prentice Hall - Greg Doench for his patience (we did slip this thing a few times) and support vii viii Acknowledgements • Thanks to our enduring copy editor, Mary Lou Nohr for her top notch editorial work and style suggestions Without your help, this book wouldn’t be what it is today From Jim: I wish to personally acknowledge Jeff Bonwick and Andy Tucker of Solaris kernel engineering They demonstrated great patience in clarifying things that were complex to me but second nature to them They answered innumerous emails, which contributed significantly to the accuracy of the text, as well as insuring all the key points were made They also provided some wonderful explanations in various areas of the source code, which definitely helped Roger Faulkner and Jim Litchfield, also of Solaris kernel engineering, deserve and additional note of thanks for their efforts and time Thanks to Nobel Shelby and Casey Palowitch for reviewing sections of the manuscript and providing insightful feedback and suggestions I owe a debt of gratitude to Hal Stern that goes way beyond his support for this work His mentoring, guidance and friendship over the years have had a profound impact on my development at Sun Last, but certainly not least, comes the family acknowledgment This may appear cliche’, as every technical book I’ve ever seen recognizes the writers family in the acknowledgements section Well, there’s a very good reason for that There are only 24 hours in a day and days in a week That doesn’t change just because you decide to write a book, nor the other things that demand your time, like your job, your house, your lawn, etc., all of a sudden become less demanding So the ones that end up getting the short end of the stick is invariably your family Thus, my deepest gratitude goes to my wife Donna, and my sons, Frankie and Dominick Without their love, sacrifice and support, I would not have been able to complete this work Thanks guys, I’m back now (of course, there is that pesky little matter of the updated version for Solaris ) Jim Mauro jim.mauro@eng.sun.com Green Brook, New Jersey June, 2000 Acknowledgements ix From Richard: I would like to thank Adrian Cockcroft and Brian Wong for first giving me the opportunity to join their engineering group in 1995, working from my remote outpost in Australia Their leadership and guidance has meant a lot to me during my career at Sun Thank you to our friends, visitors and family who seemingly understood for years when I abstained from many invites to dinners, day trips and fun events citing “when the books done ” Yes - it is done now! And yes, a special thank you to my wife Traci, who provided a seemingly endless amount of encouragement and personal sacrifice along the way This project would have been forever unfinished without her unquestionable co-operation and support Richard McDougall rmc@eng.sun.com Cupertino, California June, 2000 x Acknowledgements 674 Index Index 675 676 Index Index 677 678 Index Index 679 680 Index Index 681 682 Index Index 683 684 Index Index 685 686 Index Index 687 688 Index ... INTRODUCTION TO SOLARIS INTERNALS An Introduction to Solaris A Brief History Key Differentiators Kernel Overview 10 Solaris Kernel Architecture... Figure 2.11 Figure 2.12 Figure 3.1 Figure 3.2 Figure 3.3 Solaris Kernel Components 12 Core Kernel and Loadable Modules 13 Kernel Threads, Processes, and Lightweight Processes 15... the Solaris kernel framework and architecture It should also be noted that the source available from Sun is Solaris source Although this book covers Solaris versions up to and including Solaris