Linux 4.20 Released in Time for Christmas (betanews.com) 47
Besides new hardware support when it comes to graphics processors, in the DRM driver space there is also VCN JPEG acceleration for Raven Ridge, GPUVM performance work resulting in some nice Vulkan gaming boosts, Intel DRM now has full PPGTT support for Haswell/IvyBridge/ValleyView, and HDMI 2.0 support for the NVIDIA/Nouveau driver. On the CPU front there are some early signs of AMD Zen 2 bring-up, nested virtualization now enabled by default for AMD/Intel CPUs, faster context switching for IBM POWER9, and various x86_64 optimizations. Fortunately the STIBP work for cross-hyperthread Spectre V2 mitigation was smoothed out over the release candidates that the performance there is all good now.
Btrfs performance improvements, new F2FS features, faster FUSE performance, and MDRAID improvements for RAID10 round out the file-system/storage work. One of the technical highlights of Linux 4.20 that will be built up moving forward is the PCIe peer-to-peer memory support for device-to-device memory copies over PCIe for use-cases like data going directly from NICs to SSD storage or between multiple GPUs.