While corporate giants such as IBM, Novell,and Red Hat continue to play a significant role in Linux kernel development, wireless companies and their suppliers are rapidly stepping up, according to a report from the Linux Foundation.
The Linux Kernel Development report, released Dec. 1, examines how fast it's growing and the developers contributing to the project. Since the paper's last update, in August 2009, there have been 1.5 million lines of code added to the kernel, at the rate of 9,058 lines added, 4,495 lines removed, and 1,978 lines changed every day, said Linux Foundation's Amanda McPherson, one of the report's three authors. The other authors were Novell's Greg Kroah-Hartman and LWN.net's Jonathan Carbet.
More mobile and embedded companies are participating and sponsoring the Linux Kernel, according to McPherson, listing wireless companies like Nokia, Texas Instruments, and Renasas. Red Hat, IBM, and Novell remain the three largest corporate sponsors for kernel development, but the list also includes Samsung, Sony and AMD.
"This certainly should not be a surprise given the rise of Linux usage in devices over the last few years," wrote McPherson.
With the growing popularity of Google's Linux-based Android operating system for smartphones and other mobile devices and the excitement surrounding Intel's and Nokia's joint MeeGo project for tablets, Linux is becoming a key player in the mobile market. All top smartphone makers, excluding Nokia and Apple, have at least one Android phone in their product lineup. Nokia is expected to rollout a slew of MeeGo devices in 2011.
Over 6,100 individual developers from over 600 companies have contributed code to the kernel since 2005, according to the Linux Foundation. The number of developers, participating companies, and the rate code is being added, have been increasing steadily for each release since 2008, according to the report.
According to the report, "over 70 percent of all kernel development is demonstrably done by developers who are being paid for their work."
Significant features were added to the 2.6.30 release of the kernel in 2009, including Btrfs, perf, and ftrace. The report found that less code was submitted for the latest 2.6.35 release, and the number of developers has also dropped slightly. There's a "step back from the frenzied activity" of the 2.6.30 release, according to the report.
There were 11,989 patches for 2.6.30, compared to a mere 9,801 patches for the 2.6.35 release, according to the report. While acknowledging that development rates are "naturally variable" and that kernel development rate has often dipped over time, the authors noted that since 2.6.30, several long-term projects have been completed. The projects include the ext4 and btrfs filesystems, ftrace and perf events subsystems, and the reimplementation of the graphics layer.
"Rates of change will naturally slow as the finishing touches are put on these developments," the authors wrote.
"The pace of kernel development as a whole can be expected to increase as developers take on new challenges in the future," said the authors.
On average, a new release of the kernel is released every 8 to 12 weeks, or on average, about 81 days. The most recent kernel version, 2.6.35, was released in August.