Understanding The Linux Virtual Memory Manager by Mel Gorman

Reviewed by Ron Steinke

This book is one of the Bruce Perens' Open Source Series.

Of the 726 pages in this book, 215 describe the concepts, principles, and "real world" considerations in the design and implementation of the Linux VMM.

Thirteen appendices, a page on references, and a 16 page index comprise the remainder of the book. Although the book is written for VM 2.4 it also sets the stage for 2.6 by describing current directions and expectations for that release.

Gorman starts with a short tutorial on downloading and using the source code - including how to submit patches. He continues with a description of concepts used to describe physical memory including zones, nodes and pages. He goes on to Page Table Management and subsequently covers everything from Process Address Space through Swap Management and Shared Memory Virtual Filesystems. Gorman then comes full circle back to the source code.

The remainder of the book consists of appendices, each corresponding to one of the preceding chapters, with a commentary on the core code for that chapter . Each appendix has a detailed table of contents which makes it very easy to find any particular piece of code. The code itself is presnted short sections with a line by line commentay.

I have to say that I was a little skeptical of Gormans approach when I noted the length of the apppendices in relation to the text. Reading the book dispelled my skepticism. Gorman's approach combines the right amount of theory and "real world" considerations with the actual implemtation commented in a way to make it highly readable and comprehensible. This book is a welcome addition to my Linux reference library.