The Linux Foundation today pulled back the covers on the kernel to show just who is writing all that code. The Linux Foundation released a report titled “Linux Kernel Development: How Fast it is Going, Who is Doing It, What They are Doing, and Who is Sponsoring It.” Jonathan Corbet, Greg Kroah-Hartman and Amanda McPherson dissected years of code commits to answer this question at the Linux Collaboration Summit in San Francisco.
In previous years, the “Who Writes Linux” report has focused on business entities and their relative contributions. This year’s report, however, breaks things down on a more individual basis.
According to the report, most of the code in the Linux kernel is written by a handful of dedicated contributors. “Despite the large number of individual developers, there is still a relatively small number who are doing the majority of the work,” said the report.
“In any given development cycle, approximately 1/3 of the developers involved contribute exactly one patch. Over the past 5.5 years, the top 10 individual developers have contributed 9% of the total changes, and the top 30 developers have contributed just over 20% of the total.”
The report did detail corporate contributions, however. Overall, Red Hat remained the top contributor to the kernel, with over 7,000 patches submitted since kernel version 2.6.36, and 11.9% of the overall code in the kernel. But after Red Hat, the picture is changing. If all committed changes to the kernel are considered, Novell is the second most prolific contributor of all time, with a 6.4% share of the code written. However, since the release of 2.6.36, Intel has unseated Novell, with over 5,000 patches committed upstream since that release.
During that same period of time, Novell only contributed 3,050 patches. That places it in third place for corporate entities contributing to Linux. IBM and Texas Instruments round out the top five respectively.
The 2.6.36 release is used as a cutoff date because last year’s “Who Writes Linux” report was released shortly after the release of kernel 2.6.35 in August of 2010.
In the one year since the last report, the top individual contributing to the Linux kernel was IBM’s Mark Brown. In his work at IBM’s Linux Technology Center, he has managed to crank out 887 changes to the kernel since last year.
Thomas Gleixner, of the Open Source Automation Development Lab, took second place with a hair under 800 changes committed since last year.
The report also pointed out that over 75% of all the developers committing code to Linux are being paid to do so by a third party, such as IBM, Oracle or Red Hat.
Finally, the Linux kernel’s workhorses—Greg Kroah-Hartman and David S. Miller—continue to power the project with their enthusiasm and supervision. Between them, they’ve signed off on over 14,000 lines of code for the kernel since the release of 2.6.36. The pair account for over 9% of all commit code reviews.