10 October 2008, 08:38

Kernel Log: Linux 2.6.27 Released

What's new in Linux 2.6.27

Thorsten Leemhuis

New and improved Wi-Fi drivers now allow the kernel to routinely deal with a considerably higher number of 802.11n Wi-Fi chips than before. Add the gspca webcam driver and a host of further changes to kernel drivers and infrastructure and you get a Linux kernel with much better hardware support and a much wider range of features; in addition, 2.6.27 is said to be faster and better scalable than its predecessors.

Almost twelve weeks after the release of Linux kernel 2.6.26, Linus Torvalds has now released 2.6.27, the next kernel version to emerge from the main development branch of Linux. With more than a million new, changed or rearranged lines of source code once again offers many changes which will eventually benefit normal users even if they don't usually deal with the central structures of their Linux systems.

Two new and several improved Wi-Fi drivers considerably improve the Wi-Fi support in Linux. While the uvcvideo USB webcam driver was added in 2.6.26, version 2.6.27 now also offers the gspca webcam driver to further improve webcam support under Linux – future Linux kernels and the corresponding distributions can, therefore, communicate with a wide variety of Wi-Fi chips and webcams "just like that", without requiring the user to take care of any driver configuration or installation. A large number of more, less or even less important driver adaptations as well as numerous changes to the infrastructure surrounding the drivers extend or further improve the Linux kernel's hardware support.

As with every new Linux version from the main development line there is also a large number of improvements to the infrastructure of the kernel itself. For example, Linux version 2.6.27 is the first to support the UBIFS file system suitable for Flash memory – the kernel hackers also continue to develop the Ext3 successor Ext4, which is soon expected to be ready for everyday use. Some restructuring measures initiated by open source purists optimise the kernel's internal firmware handling, while numerous Big Kernel Lock (BKL) calls were edited out to further improve the operating system's performance and scalability. There are also numerous improvements to the utilisation of the ACPI S3 (standby) sleep state as well as a new framework called khibernate which allows the system to go to sleep completely (hibernate). However, these are only a few of the most important improvements selected from a wealth of further more or less important changes to the infrastructure of Linux kernel 2.6.27.

The detailed changelog lists all the changes since version 2.6.26 for all those who want to know the nitty-gritty and have enough time for studying this document which is several megabytes in size. The following Kernel Log offers easier reading and presents most of the important new features of the latest kernel version. This kernel will soon operate on a great number of systems in the upcoming distributions Fedora 10 (Cambridge), OpenSuse 11.1 and Ubuntu 8.10 (Intrepid Ibex) expected in the coming few weeks and months. We'll also deal with important events during the development of 2.6.27 and provide an outlook on 2.6.28:

Kernel trends: Outlook on 2.6.28

The sections linked above describe the improvements to infrastructure and drivers which are relevant to the majority of Linux users. There is also an appendix which has a more detailed listing of the numerous further changes in 2.6.27:

Changes to the infrastructure