The Many Interesting Changes & Features So Far For Linux 4.20 (Or Perhaps Linux 5.0)

While we still don't know yet whether Linus Torvalds intends to call this next kernel Linux 4.20 or Linux 5.0, we do know that whatever the version ends up being, this is going to be a very big kernel release with a lot of new features.

Some of the work merged already or at least in pull requests waiting to land include some of the following work over week one:

- The Big DRM graphics driver updates from AMD Vega 20 features like xGMI to ongoing Intel Icelake graphics support to a lot of other open-source GPU driver activity.

- Intel's 2.5G Ethernet driver was merged.

- The Speck crypto code has been removed as the controversial NSA algorithm.

- Support for programmable LED patterns via sysfs in the LED subsystem.

- PCI peer-to-peer memory support is quite interesting for some current hardware use-cases like RDMA NICs directly to NVMe storage or multi-GPU adapters while this tech should get more interesting (and more widely supported hardware) moving forward.

- New sound hardware support including the Creative Sound Blaster ZxR, Sound Blaster AE-5, and other audio chips.

- VLAs are dead! For better security, performance, and compiler portability.

- The new XArray data structure was finally accepted into the mainline Linux kernel.

- Xbox One S controller rumble support, Logitech high resolution scrolling, and Apple Trackpad 2 support among other input device work.

- Support for AMD Zen-Based Hygon Dhyana CPUs as the new Chinese server processors being used and built within the country.

- Support for the new C-SKY 32-bit CPU architecture in Linux is queued while still awaiting a pull by Linus.

- KVM gets nested virtualization by default on x86 architectures.

- Early indications of AMD developers starting on Zen 2 / EPYC 2 upstreaming work.

- Scheduler improvements to deal with tasks on an asymmetric CPU system like ARM big.LITTLE where they were assigned to a "small" CPU core but really should have been slotted with one of the bigger cores.

- Ongoing Year 2038 preparations for the "UNIX Y2K"-like event.

- Much faster context switching on IBM POWER9.

- New IBM s390 features.

- RAID10 improvements for MD RAID / Linux Software RAID.

- Performance improvements for Btrfs.

- XFS and EXT4 mostly maintenance work.

- New F2FS file-system features.

- Better Intel IOMMU debugging experience with DebugFS support.

- Some Linux x86/x86_64 optimizations.

- Cross-hyperthread Spectre V2 mitigation via Intel STIBP.

- The STACKLEAK plug-in for security.

- The I3C subsystem appears ready for finally merging to mainline.

- Lots of USB updates.

- Better x86 32-bit hibernation support.

Those are the interesting pull requests I've seen thus far and there still is just under one week to go for this next kernel merge window... There is a lot of exciting changes from new hardware support to performance optimizations and other refinements... Doesn't this feature set sound like a good time for Linux 5.0? There is new CPU support, a lot of input hardware and sound cards now supported, better security, peer-to-peer PCI memory, XArrays, death to VLAs, better Btrfs performance, and even infrastructure work for programmable LED patterns.

Stay tuned for what happens during the rest of this merge window followed by the testing and benchmarks for this new kernel. This kernel should ultimately be promoted to a stable release around the very end of 2018 or in the early days of 2019.