KernelNewbies:

Linux 3.12 [https://lkml.org/lkml/2013/11/3/160 was released on November 2, 2013]

Summary: /!\ /!\ /!\ This page is being written. Sorry for the delay /!\ /!\ /!\

Other news sites that track the changes of this release: LWN [https://lwn.net/Articles/565715/ part 1], [https://lwn.net/Articles/566122/ part 2], [https://lwn.net/Articles/566546/ part 3]

TableOfContents()

1. Prominent features

1.1. Offline data deduplication support in Btrfs

The Btrfs filesystem has gained support for offline data deduplication. Deduplication consists in removing copies of repeated data in the filesystem, since the data is the same only one copy is neccesary. In some particular workloads, like virtualization VMs -which often contain similar copies of operating systems- the gains can be enormous. By "offline", it means that the deduplication process is done when the file system is mounted and running, but it's not done automatically and transparently as processes write data, but rather it's triggered by userspace software at a time controlled by the system administrator. Online deduplication will be added future releases.

Gabriel de Perthuis also has a branch in his bedup deduplication tool which works against this support. The branch can be found at: https://github.com/g2p/bedup/tree/wip/dedup-syscall

The author of the deduplication support, Mark Fasheh, has also written an sample deduplication tool, duperemove, which can be found here: https://github.com/markfasheh/duperemove

Code: [http://git.kernel.org/linus/416161db9b63e353a8fb79d1369779175102fca1 commit]

1.2. Massive graphic performance boost for AMD Radeon hardware

The website [http://Phoronix.com Phoronix.com] found that graphic performance in modern AMD Radeon GPUs had improved a lot in Linux 3.12. However, there hasn't been any important modification on in the Radeon driver that can cause such massive gains. After [http://www.phoronix.com/scan.php?page=article&item=linux_312_performance&num=1 some investigation], Phoronix found out that the responsible change for this boost wasn't a change in the Radeon driver itself, but [http://anzwix.com/a/Linux%20Kernel/CpufreqOndemandChangeTheCalculationOfTargetFrequ a change to the algorithms in the cpufreq ondemand governor]. Apparently, the ondemand governor was oscillating too much between frequencies, and this oscillation harmed graphic performance for Radeon GPUs. The new algorithm added a better frequency algorithm that eliminates this problem.

Code: [http://git.kernel.org/linus/dfa5bb622555d9da0df21b50f46ebdeef390041b commit]

1.3. DOCUMENT BEING REDACTED RIGHT NOW, MORE FEATURES WILL BE ADDED

2. Drivers and architectures

All the driver and architecture-specific changes can be found in the [http://kernelnewbies.org/Linux_3.12-DriversArch Linux_3.12-DriversArch page]

3. Core

4. Memory management

5. Block layer

6. File systems

7. Networking

8. Crypto

9. Virtualization

10. Security

11. Tracing/perf

KernelNewbies: Linux_3.12 (last edited 2013-11-04 16:07:10 by diegocalleja)