More of the features of the Linux 3.9 kernel will be known as soon as its merge window opens in the coming weeks following the 3.8 availability, and as the "-next" branches for the different subsystems are finalized, but here's some of the work that's already queued up:
- Kernel mode-setting locking has come courtesy of Intel. This work is to move in the direction of "perfect page-flipping", but it's not there quite yet even after the invasive changes caused by this locking work. The changes are to avoid blocking KMS background functions when ioctls being frequently hit by the compositor are called, in order to reduce dropped frames. So while this isn't some sexy end-user feature, it's an important improvement to the KMS/DRM infrastructure.
- The Intel no-reloc optimization will provide for a possible few percent performance improvement for certain tasks.
- Open-source Radeon driver support for the AMD HD 8000 series GPUs. The Radeon HD 8000 hardware hasn't launched yet, but the required driver changes for the open-source Linux GPU driver aren't too massive over the HD 7000 series, so AMD recently released the code.
- Various other Radeon DRM improvements including a rework to how GPU hardware resetting is dealt with, re-factoring the command submission ioctl, and using an indirect buffer for pumping in the VM PT updates. This next kernel also deprecates Radeon user-space mode-setting support.
- Page-flipping and planes support for the open-source NVIDIA Tegra driver.
- Better support for Intel Haswell processors that are due to launch in the near future. Plus other i965 DRM driver changes.
- The EnhanceIO SSD caching driver for using solid-state drives as caches for rotating media should enter the kernel's staging area.
- Greater support for Google Chromebooks, including the Samsung Series 5 Chromebook with its Exynos 5 Dual (Cortex-A15) ARM SoC.
- It doesn't look like it's been merged into any -next trees yet, but it's possible to see LZ4 kernel compression support.
- The Meta Linux Kernel Port for their processors from the company notorious for their PowerVR graphics drivers, Imagination Technologies.
- Synopsys ARC CPU support for these embedded processors.
- Initial support for Intel Avoton.
- Early support for NVIDIA's Tegra 4 (Wayne) Cortex-A15 SoC.
- ACPI support improvements for bettering Linux power management.
- Intel HDA Audio is massively overhauled to vastly improve the Linux audio support.
- Linux Zswap for compressed swap caching.
Stay tuned for more feature details of the Linux 3.9 kernel in the coming weeks as we get a better idea what else will be merged (especially in the non-graphics areas). What we will still not see with Linux 3.9 is definitely VIA kernel mode-setting or the Reiser4 file-system; I'm beginning to wonder if either of these long-developed features will ever reach a mainline state even though they continue to be toyed with to this day.