The first release-candidate of the 2.6.22 Linux kernel has been released into the wild. 2.6.22 at first glance seems to be an ‘everything but the kitchen sink release’, as according to Linus:

The diffstat and shortlogs are way too big to fit under the kernel mailing list limits, and the changes are all over the place. Almost seven thousand files changed, and that’s not double-counting the files that got moved around.

Later in the mailing-list mail he discusses some high level indicators of what has changed (see above for the link). For those curious, here is, I believe, the full change-log - and it is certainly a doozie.

Here are some notes of interest:

SLUB

SLUB is a new memory allocator for Linux. This is a pretty significant change, as Linux has had the SLAB allocator since the 2.2 kernel - so several years. You can read about traditional SLAB algorithm allocation on Wikipedia.

On the other hand, SLUB (which basically stands for unqueued SLAB). While the SLUB codebase brings with it a huge number of changes, the original claim-to-fame of SLUB is the removal of the queues that SLAB uses to manage allocation. Apparently for anyone close to the current SLAB memory manager, the queue implementation can get a little hairy from a complexity standpoint.

You can read about SLUB here.

New Firewire Stack

I’m not a firewire user, so I didn’t track this actively, but there were over 50 patches with the keyword ‘firewire’ in their summary. All indicators of the new firewire stack in the kernel.

Blackfin Processor Support

The Blackfin Processor is a relatively new embedded multimedia CPU that can be used in devices like a camcorder or a handheld video player.

New Wireless Configuration Infrastructure

I had to dig a little bit for this one, as I was certainly curious. Wireless networking is a big deal for continued Linux adoption, and so I tried to track down a little bit of info. The biggest changes involve ‘cfg80211’, which is the new configuration layer for the ‘d80211’ wireless layer. There is a good article about this from Steven J Vaughan Nichols here.

I seriously doubt I will move to 2.6.22-rc1 in the very near future; I’ll probably wait until it goes final and then subsequently is adopted in a distribution, but all the same it’s good to see another aggressive release happen; it’s just what Linux needs.