Kernel release status [LWN.net]

The current development kernel is 2.5.70, which was released, at long last, on May 26. This massive patch includes the beginning of Alexander Viro's character device rework for a larger dev_t type (see below), some NFS fixes, sysfs support for network devices, an XFS update, some scheduler fixes, a change to the request_module() prototype, some framebuffer fixes, more annotations of user-space pointers and makefile support for Linus's kernel source analyzer, 48-bit IDE addressing support, a (hopefully) working IDE tagged command queueing implementation, the BIO "walking" and splitting APIs, more devfs cleanups (devfs_register() is gone), the USB "gadget" subsystem, a wireless networking update (and quite a bit of networking work in general), dynamic block I/O request allocation, a fair amount of SCSI cleanup work, a generic x86 subarchitecture, a number of TTY layer cleanups, a USB update, several architecture updates, and a vast number of other fixes. See the announcement from Linus for the details, or long-format changlog for lots of really gory details.

As of this writing, Linus's BitKeeper repository contains a FAT filesystem rework (if you have been waiting to be able to create FAT partitions greater than 128GB, this patch is for you), a v850 subarchitecture merge, a RAID update, the removal of the long-deprecated callout TTY device (/dev/cua) support, and several other fixes and updates.

Andrew Morton's -mm tree is currently even more interesting than usual in that it contains a major rework of the ext3 filesystem and generic journaling code. ext3 now uses fine-grained locking - the big kernel lock is no longer used there. "These are major changes to a major filesystem. I would ask that interested parties now subject these patches to stresstesting and to performance testing. The performance gains on SMP will be significant."

For those who are curious about the source checking program that Linus has been working on, a preliminary version is now available via BitKeeper. "It's unfinished enough that I'm a bit embarrassed about some of it, but I've gotten the permission from Transmeta to make it open source".

The current stable kernel is 2.4.20, though 2.4.21 may be out by the time you read this. As of this writing, the fifth 2.4.21 release candidate is available with a small set of fixes. This release has an issue with pauses related to the block subsystem; a small patch exists (and is merged into 2.4.21-rc5-ac1) which fixes this problem.