Frequently Asked Question

Who maintains the kernel? What is Linus's role, and what are subsystem maintainers?

The Linux kernel is developed by roughly 4,000 people each year, but its governance is not a vote: it is a tree of trust. At the top is Linus Torvalds, who maintains the mainline tree on kernel.org and decides what gets merged into each new release. Below him sit roughly a hundred subsystem maintainers, each responsible for one area; networking, the scheduler, USB, a CPU architecture, a filesystem, the stable branch; and below them sit the maintainers of individual drivers and components.

Patches flow upward. A driver fix goes to the driver maintainer, who sends pull requests to the subsystem maintainer, who sends a pull request to Linus during the two-week merge window. Greg Kroah-Hartman runs the stable branch, which back-ports fixes into older kernel series, and is one of three full-time Linux Foundation Fellows alongside Linus and Shuah Khan. The MAINTAINERS file in the kernel tree lists who owns what; running scripts/get_maintainer.pl on a patch tells you whom to send it to.