1. 9/28/2016 The Linux Kernel Developers Community Jean DELVARE SuSE R&D, Kernel support Solutions Linux 2007, January 31st, 2007

2. Organization

3. Global Organization (1) ● Linux Foundation ● Merge of the OSDL (Open Source Development Labs) and the FSG (Free Standards Group) in January 2007 ● Employs 45 people including Linus Torvalds ● Works on the distributions standardization (LSB) ● Offers a legal protection ● kernel.org ● Distributes the kernel source code ● Offers services to the developers

4. Global Organization (2) ● Large companies ● Red Hat, Novell, Oracle... ● IBM, Intel, SGI, HP... ● All the others ● Small businesses ● Universities, researchers, students ● Public services ● Individuals

5. Some Figures

6. Statistics for year 2006 2005 ● 20,788 changes ("patches") ● 1356 contributors 2006 ● 27,689 changes (+33%) ● 1771 contributors (+30%) ● 400 maintainers ● 116,040 posts to the LKML (+17%)

7. Contributors casualonce a quarter once a month once a week several each week

8. Contributions Core contributors (76%) Regular contributors (20%) Casual contributors (4%)

9. Development Flow Core maintainers Subsystem maintainer Subsystem maintainer Subsystem maintainer Driver maintainer Driver Maintainer Developer Driver Maintainer Driver Maintainer

10. Development Model

11. In Search Of The Perfect Model Users want: ● A stable kernel ● Fixes for bugs that affect them ● Support for their new hardware ● Optimizations which help them ● No regression on upgrade Developers want: ● To see their work tested and used quickly ● To avoid doing the same thing twice

12. Old Development Model Two branches: ● Stable branch (e.g. 2.4) ● Development branch (e.g. 2.5) If the separation is strict: ● Development branch receives little testing and quickly becomes unstable (vicious circle) ● Major improvements awaited for a long time ● New hardware unsupported by the stable branch ● Divergence makes it difficult to backport bugs ● Stable branch not functional enough for some If the separation is loose: ● Developers time shared between both branches ● Stable branch not stable enough for some

13. Code Volume

14. New Development Model (1) To each one his/her job: ● Developers of the community develop. ● Distributions do support and maintenance. ● Users who want stability over all should trust their distribution. New model: ● Single branch ● Stable enough to be broadly used and serve as a base for future distributions. ● Model can be refined over time.

15. New Development Model (2).1 9 - rc 1.1 8 - rc 2 - rc 6 - rc 1.1 8. 1.1 8. 2.1 8. 6.1 9. 1 -mm-mm -mm-mm -mm-mm Stable branches Testing branch Integration branch 20 sept. 200629 nov. 2006

16. New Development Model (3) 2.6.19 2.6.18 2.6.17 2.6.16 2.6.15 2.6.14

17. Questions?