Open-source developers on Sunday released the latest stable version of the Linux kernel, version 2.6.26, adding improvements for wireless, virtualisation, multimedia and other features.
New kernel editions are normally adopted as rapidly as possible into mainstream Linux operating system distributions, bringing the new features directly into use on production systems.
The new kernel appears three months after version 2.6.25, a longer-than-usual release cycle, Linux creator Linus Torvalds said in an email announcing the release.
Among the most significant improvements are changes to the Kernel-based Virtual Machine (KVM) virtualisation software, first included in the kernel in February of last year. KVM normally uses the technique of full virtualisation, which simulates all the underlying hardware necessary to run a given client system, with the support of virtualisation technologies built into AMD and Intel chips. The latest kernel update adds limited support for paravirtualisation, a technique that only partially virtualises the hardware in order to improve performance.
KVM has also, for the first time, been ported to non-x86 hardware platforms Intel IA64 and IBM PPC and S/390, developers said.
The new kernel builds on the wireless stack added in version 2.6.22 by adding support for the draft wireless mesh standard 802.11s, using work provided by the Open80211s project. Mesh is a network topology in which nodes act as relays for each other, providing the potential of better redundancy and higher overall throughput than in a traditional star topography.
With version 2.6.26, the kernel for the first time gets a built-in debugger, despite Linus Torvalds's previous warnings against such things. In an email quoted with the new kernel's release notes, Torvalds said not having a built-in debugger forces users to be more careful. "I happen to believe that not having a kernel debugger forces people to think about their problem on a different level than with a debugger," he wrote. The remote debugger KGDB will nevertheless appear in the kernel due to popular demand, developers said.
Other additions to the kernel include improved webcam support with a driver for UVC devices, a built-in memory tester, support for the One Laptop per Child (OLPC) project, new features for a virtualisation technology called containers, and various new drivers.
The kernel is available from the Linux kernel website.