The shape of 2.6.26
On May 3, Linus announced the release of the 2.6.26-rc1 prepatch and the closure of the merge window for this development cycle. So now we know what will be in 2.6.26, which, I predict, will be released sometime around the beginning of July.
Many developers will be pleased by the addition of the KGDB debugger for the x86 architecture at last. For as long as I have been following Linux development, Linus has opposed interactive debuggers; he fears that they cause developers to look at symptoms and miss the true causes of bugs. After all this time, a dedicated group of developers was able to put together a version of KGDB that Linus could stand, though, and so in it went. The merged version lacks some useful features, such as KGDB-over-ethernet, but those can be obtained with external patches and, with luck, will make it into the mainline sometime in the future.
When the OLPC folks made mesh networking work on the XO laptop, they put the bulk of the code into the “Libertas” driver for the XO’s Marvell-based network chip. That code ran into difficulties at merge time because the networking developers thought that the mesh features should be implemented at a higher level where they would be useful for a wider range of devices. So Libertas was merged without mesh networking. Now, though, a more generic mesh networking implementation has found its way into the mac80211 layer. That, too, will be part of 2.6.26.
Other nice features include page attribute table (PAT) support, which should help ease a number of hardware-related hassles. There’s a braille screen reader layer. A lot of containers work has gone in, pushing that capability closer to completion. And so on.
But one thing that is notable about this cycle is that it is relatively small. 2.6.25 finished out at over 12,000 individual changes; 2.6.26, at this point, has some 7500. It would appear that, after two cycles of intensive merging, the developers are slowing down just a little bit. So there’s rather fewer new features this time around. That may lead to a shorter development cycle for 2.6.26 and, perhaps, fewer problems to fix on the way there.