Linus Torvalds and the Linux kernel maintainers on stage today at LinuxCon and CloudOpen covered a range of topics, from personal hobbies to advice for getting patches upstream. But one consistent theme emerged in the discussion: Growing the size and diversity of the Linux kernel developer community -- on the kernel side as well as in user space -- will help push continued innovation even as technology changes.
More than 10,000 developers from more than 1,000 companies have contributed to the Linux kernel since tracking began in 2005, according to the Linux Foundation's annual development report released this week. The sheer size of the project may be intimidating for newcomers, but the number of developers involved also shows just how many people have found ways to contribute, Torvalds said.
"The kernel can be hard to get involved with because it's big and complicated," Torvalds said during the keynote panel. "But it can be easier than other open source projects because we have so many things you can do."
Unlike proprietary projects overseen and built within a single corporation, the Linux kernel will take contributions from anyone who submits good code. Before Tejun Heo, became a kernel developer, he was passionate about operating systems. But he lived in Korea and wasn't sure how he'd get a job at one of the companies building them. There was no Microsoft or Sun in Korea and he didn't speak enough English to qualify, he said.
"But with Linux it didn't matter where I came from or what degree I had. If you can do it, you can do it. It doesn't matter who you are are where you came from," said Heo, who now works for Red Hat.
Heo says he's seen an increasing interest and level of contribution from developers and China, which he predicts will be the next hot country from which Linux developers are recruited.
The kernel community this year has also ramped up its recruiting efforts among women. Kernel developer Sarah Sharp, who works on the USB subsystem for Intel, oversaw the first Outreach Program for Women Linux kernel internships this summer. Women accepted into the program were paired with mentors in the kernel development community to learn more about the Linux development process and gain direct experience writing and submitting patches.
Linux stable kernel maintainer Greg Kroah-Hartman, who was a mentor in the Outreach Program for Women, said the intern working with him submitted more than 60 patches this summer and many will be merged.
"My goal is to see Linux continue to succeed. We need to keep changing along with the rest of the world and make sure that more people are contributing," Kroah-Hartman said.
Recruiting efforts to increase kernel contributions extends beyond individuals to companies as well. For companies that base their products and processes on Linux, getting involved in the kernel community by submitting their own patches upstream is one way to help increase the quality of their own offerings as well as the kernel as a whole.
Kroah-Hartman urged companies to get involved with the kernel community really early in the design and integration cycle to ensure the patches they need to get upstream for their hardware have time for review.
"Intel really understands this, we ripped code out of the kernel for an Intel chip that never shipped," Kroah-Hartman said.
Torvalds agreed that being early was helpful, but just as important was being really involved in the community in the first place. Instead of building patches within the walls of your company, work with the kernel community to find common problems and solve them together.
"In order to get things merged you need to solve not just your problem," Torvalds said. "Realize the kernel is bigger than your company."