Linux 5.18 Preparing For Release - Especially Heavy With Many Intel & AMD Changes
Linux 5.18 has a great number of changes as usual. Below is a look at some of the items that caught my attention the most, especially as it pertains to the uptick of Intel and AMD work ahead of new product launches and landing other new drivers.
Linux 5.18 has many Intel additions this cycle including the new Hardware Feedback Interface (HFI) driver for hybrid processors like Alder Lake, Software Defined Silicon (SDSi) was merged for activating licensable silicon features with future Intel CPUs, Intel Indirect Branch Tracking (IBT) as part of Control-Flow Enforcement Technology, ENQCMD is re-enabled for Sapphire Rapids, and more. Intel PECI as the Platform Environment Control Interface was also merged for interfacing between the CPU and BMCs on Intel server platforms. Preparations for Intel IPI virtualization also landed in 5.18 while the actual enablement should be here for the v5.19 cycle.
For Intel in the graphics space, Linux 5.18 brings DG2 G12 sub-platform support, Intel Alder Lake N graphics support, and various DG2/Alchemist enablement bits. But it's for Linux 5.19 where it is looking like the Arc Graphics DG2/Alchemist support will be all in good shape for the initial roll-out of the desktop graphics cards in the months ahead.
Over on the AMD side there is scheduler updates around NUMA balancing that in particular can further boost the performance of AMD EPYC servers. There is also the new AMD HSMP driver for the Host System Management Port on AMD server platforms. There are also AMD EDAC preparations for Zen 4 CPUs, AMD nested virtualization enhancements, and other Zen 4 preparations. KVM with Linux 5.18 also now supports AMD virtual machines up to 511 vCPUs, up from the current 255 vCPU limit and ahead of next-gen EPYC servers delivering higher core counts with Bergamo.
When it comes to AMD on the graphics front, Linux 5.18 enables the AMDGPU FreeSync "Video Mode" by default now where as on prior kernels was hidden behind a module option. There is also early IP blocks enabled for next-generation GPUs and APUs but more of that is coming in the 5.19 kernel.
Outside of the AMD and Intel changes, Linux 5.18 brings mainline support for the Raspberry Pi Zero 2 W and Tesla's Full-Self Driving (FSD) chip that is manufactured by Samsung. Some of the other smaller items include improved sensor monitoring on newer ASUS motherboards, ACPI Platform Profile support for AMD-powered ThinkPads, ReiserFS is now deprecated, switching from C89 to C11 as the Linux kernel C language standard, and various file-system enhancements.
Find out more about these and other changes with the much larger complete Linux 5.18 feature overview. More Linux 5.18 benchmarks and then coverage of the Linux 5.19 merge window coming up on Phoronix.