A year after Linux kernel development was cleft in three, users and vendors report the process has improved the speed and quality of development.
When developers opted to nix a separate 2.7 kernel development at the Linux Kernel Developers Summit last summer, the decision spawned three 2.6 trees: the mainline or stable kernel, known as 2.6.x, maintained by Linux founder Linus Torvalds; the 2.6-mm, or staging tree, where technologies are tested before being added to the mainline kernel; and the 2.6.x.y kernel, for bug fixes.
"The hierarchy in the community has flattened, so now you have small teams of experts working at consensus level rather than having a maintainer and all the subordinates," said Dan Frye, director of IBMs Linux Technology Center in Beaverton, Ore.
"We are just delighted. The stuff our enterprise customers need is getting done, and that is translating into shipments of high quality from the distributions," Frye said.
The companies that produced the Linux distributions, such as Red Hat Inc. and Novell Inc., also now have greater choice about which build of the kernel best suits their customer needs rather than having to wait for the final stable release, Frye said.
Some large enterprise Linux customers welcome the development changes as well. John Engates, chief technology officer for Rackspace Ltd., a managed-hosting provider in San Antonio, said incremental technology updates along with the introduction of enterprise Linux distributions had slowed the endless upgrade treadmill of the past.
One of the biggest consequences of the three-pronged development approach, "was that Linus started trusting the subsystem maintainers more, which helped speed up the process," according to Greg Kroah-Hartman, a Linux kernel developer with Novell, in Portland, Ore.
The number of unique kernel developers has risen to more than 1,000 with the 2.6 kernel from the 961 working on the 2.4 kernel, all of whom were sending patches up the chain, Kroah-Hartman said.
Torvalds said Linux vendors tended to appreciate more gradual upgrades, rather than the huge, painful jumps of the past.
"Im certainly pleased, and judging from the reactions we had at the Linux Kernel Developers Summit in Ottawa a few weeks ago, most everybody else is, too," Torvalds said.
While Torvalds was upbeat about the past years changes to the development plan, which he said have significantly improved the kernel development process, he left the door open to create a 2.7 tree "if we hit some fundamental change that makes us split into a 2.7.x tree."
"We havent hit anything yet, but if something really fundamental rears its ugly head, we still accept the possibility that wed have to do a full unstable branch split," Torvalds said.