All of the major subsystems with updates for the Linux 3.16 merge window appear to now be addressed and Linux 3.16-rc1 is likely hours away. As I'm about to leave for Russia again, I'm writing my summary of the features I'm most interested in with the Linux 3.16 kernel and other changes/improvements that you as Phoronix readers will also be most pleased to see with this new kernel stabilizing over the summer.
- Nouveau has initial GK20A GPU support. The GK20A is the Kepler GPU found within the Tegra K1 SoC. NVIDIA contributed this GK20A support themselves and there's also outstanding Nouveau Mesa patches to allow for this latest NVIDIA ARM chip to work with a fully-open driver stack!
- Also big for the Nouveau driver in Linux 3.16 is initial support for re-clocking with Kepler hardware and other select chipsets. However, the support is still considered experimental, performance levels are statically controlled via sysfs, and how well it works may vary a lot.... I've tested all my Kepler GPUs already and have two articles coming out in the next few days covering the support: an article tomorrow covering for Linux enthusiasts how to actually use the re-clocking support and its limitations, etc, then an article later in the week with my actual Linux 3.16 Nouveau re-clocking results for Kepler GPUs. But if you try the support out yourself before then, watch out for bugs.
- The Nouveau changes round out with an assortment of other work including support for newer GK110 Kepler GPUs, DisplayPort rework, and fixes for other recent NVIDIA GPUs.
- On the Intel DRM graphics side is the usual big amount of work given their large, paid staff at the Open-Source Technology Center. There we have cursor support for up to 256x256 pixels to better handle cursors on HiDPI displays, Cherryview graphics support for the new Atom SoCs coming out in a few months with Broadwell-based graphics, better Broadwell support, and various other improvements.
- The big changes on the AMD side are GPU VM and PTE optimizations along with HDMI deep color support and various bug-fixes. Coming up soon I already have conducted Linux 3.15 vs. 3.16 performance benchmarks of the Radeon DRM performance optimizations, which can be very noticeable for those with Radeon HD 7000 series hardware and newer.
- Other DRM updates including the AST DRM driver now supporting the AST2400 hardware.
- 64-bit ARM EFI stub support.
- Samsung Exynos multi-platform kernel support. The multi-platform ARM kernel image support allows for a single Linux kernel image to work on many different ARM SoCs like the Exynos, Tegra, i.MX, and OMAP chips.
- The NVIDIA Tegra K1 upstream support is now in better shape along with the support for the Jetson TK1 development board.
Other Processor / Architecture Work
- KVM improvements mainly for S390, PowerPC, and MIPS.
- ARM Xen virtualization improvements that include suspend and resume support.
- Broadwell support within Intel's P-State driver, a ARM big.LITTLE cpufreq driver on ARM64, and other power management updates.
- There's many MIPS architecture changes, including support for the Octeon III processor.
- Scheduler changes and improvements.
- Linux 3.16 now can detect if your Dell Latitude laptop is falling. The freefall sensors found within many Latitude laptops is now supported under the Linux kernel in a similar way to the HP freefall driver.
- A new Synaptics input driver and better support for the Sony DualShock 4 controller.
- Updates to many audio / sound drivers.
- Blk-mq is nearly feature-complete as the multi-queue block layer.
- Nokia N900 modem support.
- Much work on the kernel's staging drivers.
- Notable updates to Btrfs and XFS. (EXT4 really wasn't exciting this round.)
- F2FS was updated as Samsung's Flash-Friendly File-System. With F2FS in Linux 3.16 comes readahead flow enhancements, enhanced I/O flushes, support for trace-maps, support for volumes over two Terabytes, and various other fixes/improvements.
That should cover most of the interesting features and changes for Linux 3.16... See my many other Linux 3.16 kernel articles for more coverage. There's also many kernel tests coming up this month, which you can read about now, and plenty more kernel benchmarks for July.