The rapid release cycle of the Linux kernel shows no signs of slowing down anytime soon.
Linux founder Linus Torvalds this week released the new Linux 2.6.39 kernel, barely three months after the 2.6.38 kernel came out. The 2.6.39 kernel is the third major kernel release so far in 2011.
The 2.6.38 kernel release cycle included seven release candidates and Torvalds noted in a mailing list posting that he had debated whether or not to issue another candidate to provide more testing time.
"I really was struggling with the decision of whether I wanted to cut a final release at all: it could easily have made more sense to just do an -rc8," Torvalds wrote.
"However, since I'm going to be at LinuxCon Japan in two weeks, the choice for me ended up whether I should just release, or drag it out *three* more weeks, or have some really messy merge window with a break in between."
Torvalds noted that there were more code changes after the seventh release candidate than he was happy with.
"Doing another rc wouldn't necessarily have been a bad idea, but then I just decided that if I held off making the release, next week my timing choices would have been even worse," Torvalds added.
In terms of new features, the 2.6.39 kernel includes a new block device plugging model. The new plugging model is based on a per-thread approach and is intended to prevent code locking in an effort to improve Linux performance.
From a virtualization perspective, the KVM hypervisor now handles asynchronous page fault processing. Some of the virtualization improvements have already been backported by Red Hat into their new Red Hat Enterprise Linux 6.1 release.
"We are backporting things like virtualization enhancements in KVM that optimize for how level networking is handled," Tim Burke, vice president of Linux Engineering at Red Hat, told InternetNews.com. "Both in terms of how it deals with low level network queues and with the CPU scheduling efficiency of virtualized guests."
From the outset of the 2.6.39 kernel development process in March, Torvalds indicated that this wasn't going to be a release with any large new features.
"On the whole I think this should be one of those 'solid, boring progress' releases," Torvalds wrote. "Knock wood. I like boring."