Main development phase of Linux kernel 2.6.38 completed
Exactly 14 days after Linux version 2.6.37 was released, Linus Torvalds has published the first beta version of kernel 2.6.38, which is expected to be completed at the end of March or beginning of April. With this release, the merge window for the development cycle has come to an end and Torvalds has now integrated most of the changes for this version into the main development branch's source code management system.
As usual, the nearly 7,600 commits include a number of changes which even users who do not generally deal with the kernel in their Linux distribution will eventually notice and benefit from. One such change is the so called "wonder patch", which in certain situations can redistribute processor load in order to visibly speed up the reaction time of desktop applications.
Torvalds explicitly mentions the SCHED_AUTOGROUP feature in his email on the release along with the patches to improve the scalability of the VFS (Virtual File System); these have been under development for some time now and have finally been added to 2.6.38 after it was left out of 2.6.36 and 2.6.37.
Patches to support AMD's Bobcat processors are included, and the DRM Radeon drivers now also handle some of the graphics chips' 2D and 3D acceleration functions on the Radeon HD 62xx to 68xx models. The Nouveau DRM driver offers experimental, rudimentary 3D support for the Fermi chips in a number of current 400 series GeForce graphics cards, although the driver still relies on proprietary firmware. The driver for Intel graphics chips now has better support for the power saving functions in Core-i processors.
The live media for distributions will probably soon include a few more programs, because SquashFS (as of version 2.6.38), which many of them use, supports the XZ format derived from LZMA and is known for its great compression density. The new Transparent Huge Pages, which were already used in Red Hat Enterprise Linux (RHEL) 6, are intended to speed up workloads that benefit from the use of such huge pages – one example being virtualisation. In contrast, the back ends for Xen's Dom0 mode are not included, which means that we will probably have to wait for kernel 2.6.39 to be able to work as a Xen host.
As always, a large number of drivers were added or revised; for example, the rtl8192ce driver for Realtek's WLAN chips has been added for the first time. During the next few weeks, the kernel log on The H will provide more details about these and other changes.