LinuxTwo weeks later, with the release of kernel 3.8, Linus Torvalds has closed the window receiving changes to the kernel Linux 3.9 and released the first release candidate (3.9-rc1).

The announcement marked separately integration into the core support two new architectures – metag and arc, and a large number of improvements related to architecture ARM. About 60% of all changes made to the core concern of device drivers (drivers for the GPU, the networking subsystem, staging, pinctrl, sound system, etc.).

The most notable changes in the kernel 3.9:

– Experimental support for RAID5 / 6 in the file system Btrfs, the improvement of the snapshot and the acceleration of the system call fsync ();

– In EXT4 enabled realization of the possibility “punch hole” for the inode, which allows to use the files without the map extents. “Punch hole” allows you to mark the area of ​​the file as a non-binding, which can be clean if necessary. Included developments to improve the efficiency of caching extent and speed up the system call fsync ();

– A number of fixes, optimizations and improvements to F2FS, quite fast file system, focused on Flash-drives;

– Support for a new family of embedded processors – Synopsys ARC700;

– In the scheduler has some minor corrections, will significantly improve the efficiency of work in situations where the number of processors exceeds the number of active processes running. By reducing the migration process, which prevents optimal use of CPU cache after changing performance in some tests has risen to 15 times;

– The system trace ftrace added support for snapshots trace buffer with control debugfs. Snapshots allow you to fix the buffer status to study it without stopping the trace, which will continue with a separate working buffer.

Many improvements concerning energy saving:

– Includes support for optical drives with zero-energy (zero power optical disc drive) – a special mode in which the optical drive can draw power from near zero at times when not in use;

– A number of improvements and changes concerning the ACPI power management and ASPM;

– A number of other improvements and additions to the management systems of different frequencies of processors;

– Implementation of a lightweight sleep (lightweight suspend mode).

Many  improvements to support architecture ARM:

– Initial support Soc Tegra 4, which will be released in a few months;

– Support for multiple cards for developers Tegra 3 and Tegra 4;
Several patches to improve support virtualization Xen and KVM on architecture ARMv7;

– Powered by Marwell Kirkwood supports hot plug for bus PCI-E;

– Many other bug fixes and enhancements for supported ARM SoC. Increased the number of SoC, the Kernel compiled as multi-platform (one core for different SoC);

– Many improvements in the audio subsystem ALSA: Recycled support Intel HDA audio. Many drivers have been standardized and consolidated, thereby greatly reducing the cost of their continued support. A number of improvements and support for new chips in Alsa SoC (ASoC);

– Supports Google Goldfish. Goldfish – virtual processor, aimed at providing emulation platform Android, used in the development of a given platform.

Several improvements in subsystem DRM (Direct Rendering Manager):

– Improve driver Ti OMAP, such as support OMAP5 and power management;

– Changed the mechanism locking subsystem KMS;

– Optimizing (no reloc) for DRM-driver Intel, which can give a few percent increase in speed;

– Enhancements to support chip Intel Haswell, mainly dealing with power management;

– Support for page flipping in DRM-driver Tegra;

– Initial support for AMD graphics cards series HD8000;

– Many  improvements in DRM-driver Radeon: revised logic reset, use DMA rings to update VM PT etc. Additionally, support for switching video modes at the user level (UMS) finally declared obsolete and no longer be maintained;

– Speed ​​up several times LZO compression algorithm using modern processors i386/x86_64/ARM;

– Support for SBC Technologic Systems TS-5500 and systems SGI Ultraviolet System 3;

– Support touchpads Cypress PS / 2 and trackpads Cypress APA I2C;

– At the same time came the next corrective releases kernel Linux: 3.0.68 (29 patches), 3.4.35 (46 patches) and 3.8.2 (78 patches). As usual, in the announcement of new versions emphasizes mandatory update. Changes have affected such subsystems as Ext4, XFS, OCFS2, NFS, USB, ATA, cgroup, cpuset, FUSE, nbd, Xen, quota, UFI, ALSA.

Additionally, you can mark the commissioning updated website, the transition to the mandatory use of HTTPS on (for unencrypted HTTP content is now not given), and migrating from gitweb-caching on cgit to navigate Git-repository via the Web. The structure and composition of the is the same, only the changed design. For the operation of the site is now used engine Pelican, designed to generate static sites from templates with the markup, reminiscent Wiki. Lack of dynamically generated content to simplify mirroring and distribute content without losing functionality. Code generation templates can be downloaded from this repository.