Linux 3.8's features staked out
Linus Torvalds has announced the first pre-release version of Linux 3.8, releasing it on the "longest night of the year". As previously reported, it includes support for the Flash-Friendly File System (F2FS), which has been designed for use on flash storage devices such as USB flash drives, memory cards, and internal storage in devices such as cameras, tablets and smartphones.
The developers have also merged a number of basic core functions developed under the "balancenuma" name. These are aimed at enabling future kernels to automatically keep processes and the memory areas they are using in close proximity. This is important for optimum performance on today's popular multiprocessor systems with NUMA (Non-Uniform Memory Access). Further improvements likely to be merged in Linux 3.9 and later versions will significantly improve this automated placement and will build on the foundations merged in 3.8.
Code for a "huge zero page", which can reduce memory usage in some setups, has also been merged. The kmem extension for the "memory" cgroup controller can now be used to limit the memory used by the kernel for processes in a group. Appropriately configuring these limits enables the kernel to keep the lid on any fork bombs run from the shell.
The addition of inline data support means that the Ext4 filesystem is now able to store very small files together with the inode entry, thereby saving storage space. The kernel has also been given a simple driver for the graphics cores on NVIDIA's Tegra family of SoCs (system-on-a-chip). The code for using the acceleration functionality offered by these chips, which is being co-developed by NVIDIA, has, however, not yet made it into the kernel. To simplify maintenance and ongoing development, the kernel developers have removed support for Intel 386 and related CPUs. 486 and other x86-32 processors will continue to be supported.
This is, as usual, the first release of the new version of Linux, coming after the closing of the "merge window" where the majority of the changes for the new version are merged into the main development branch of Linux. The next phase, the stabilisation phase, will mostly include corrections and fixes to the new features and any regressions that appear as developers test the new kernel. Details of these and many other changes will as ever be provided by The H's Kernel Log. Assuming the kernel developers keep to their usual tempo, Linux 3.8 is likely to be released in mid-February.