Linux Kernel Architecture

Mauerer runbapp06.tex V1 - 09/04/2008 6:14pm Page 1272

Appendix F: The Kernel Development Process

things work much smoother. The Ext4 filesystem is, for instance, developed in close integration with the

vanilla kernel, and the evolving code was present in the mainline from the very beginning to receive

wide testing. Actually, the code base started out as a copy of Ext3 and was then successively modified to

integrate many new ideas and improvements.

1.10^7

1.10^7

9.10^6

8.10^6

7.10^6

6.10^6

5.10^6

4.10^6

3.10^6

2.10^6

1.10^6

12 13 14 15 16 17 18 19 20 21 22 23 24

# lines affected

Kernel Release 2.6.x

Insertions

Deletions

Both

Figure F-3: Cumulative changes in the development of the Linux kernel. The effect of the

merge window and the following stabilization period emerge very clearly.

F.2.3 Online Resources

There are numerous web sites devoted to Linux kernel development which provide useful information.

Because of the web’s rapidly changing structure, it does not really make sense to present a comprehensive

survey here, since most links will tend to become outdated rather quickly. However, relying only on

your favorite search engine to grab useful links about kernel development is also not the easiest path to

success, especially when it comes to judging relevance and quality of the results. Therefore, the following

list presents a selection of some fine links that are among the author’s personal favorites (naturally, this

selection is subjectively biased, but it’s a good starting point):

❑ The current kernel source code as well as many essential userspace tools are available from

http://www.kernel.org. Numerous git source code repositories are listed ongit.kernel.org.

❑ http://www.lwn.netisthepremier source for regular, weekly updates on the kernel development

process. And these updates are not just for the kernel. Interesting news about all aspects of

Linux development and related events in the IT community are collected on this site, and

well-researched articles provide insightful updates on the state of the art of various projects.