In a statement sent out to the Linux kernel developer mailing list (LKML) introducing Linux Kernel 6.2, Linus Torvalds enthusiastically invites people to try it out. He reminds them that even though this may not be as exciting an LTS release as 6.1 was, all standard kernels need some love too!
The 2022 Long-Term Support kernel, Linux 6.2, has officially succeeded the previous version (Linux 6.1) and will be maintained until at least 2026’s end! Once integrated into this LTS version, many of its improvements will also get backported to the prior one for those who haven’t already benefited from these fixes.
Linux 6.2: New Features
Linux 6.2 is here with an array of updates and advancements, such as enhanced hardware support, new drivers, fresh capabilities, and much more!
The kernel has undergone a major update with the introduction of Zstd compression code. The Intel IFS driver is now fully functional, and Call Depth Tracking offers Skylake-era CPUs Retbleed mitigation at a minimal cost. In addition, preparations are underway for WiFi 7 and 800 Gbps wired networking capabilities; plus, more Rust code integration has been successfully completed.
Developers and administrators now have access to AMD Zen 4 pipeline utilization data with newly released Ryzen 7000 series and EPYC 9004 series processors, allowing them to quickly and accurately identify performance bottlenecks while profiling.
Ampere Altra’s remarkable SMPro co-processor has seen several drivers uploaded to the Linux 6.2 kernel, making it even easier for users to take advantage of its many capabilities.
Not only has the strcmp() implementation for the Motorola 68000 series been broken in a subtle way on m68k, but it has gone unnoticed until now. Fortunately, fixes are already being implemented to ensure that this issue is finally resolved.
IBM did not forget about its Power/PowerPC systems when it released Linux 6.2, as the update includes a major scalability improvement for large IBM Power systems: the introduction of qspinlock! This new implementation was specifically crafted to enhance system scalability on larger architectures, providing improved performance and reliability.
With the Linux 6.2 kernel, RISC-V now supports Non-Volatile Memory devices, specifically with PMEM for memory mapping and accessing. For these capabilities to be available, both Svpbmt and Zicbom extensions in RISC-V must be enabled.
Furthermore, this version of Linux adds ftrace support for RV32 architectures, T-Head PMU support within perf subsystems, as well as many other small changes that make it a worthy upgrade from its predecessors!
Intel’s Linear Address Masking (LAM) feature was initially accepted and merged into the Linux Git repository. Unfortunately, Linus Torvalds felt that there were some serious issues present in the code and promptly retracted it from being included in version 6.2 of Linux. This means that Intel will need to go back to the drawing board with LAM before re-submitting for approval at a later date.
Intel IFS has been optimized to accommodate the In-Field Scan feature, which grants users access to CPU silicon testing capabilities for Intel’s upcoming CPUs.
Intel On Demand Driver is now available with more features and a new name, Intel On Demand, instead of the previous “Software Defined Silicon”. This exciting feature allows customers to activate select CPU features on upcoming Xeon Scalable processors.
The newest Trust Domain Extensions (TDX) developments have incorporated Intel TDX guest confirmation support.
KVM is rolling out a power savings tweak to optimize Alder Lake N and Raptor Lake P processors in anticipation of the new Intel CPU instructions. Additionally, thanks to Intel SGX Async Exit Notification (AEX Notify), users will be further safeguarded against certain kinds of SGX attacks.
Significant AArch64 enhancements, particularly dynamic shadow call stack backing, have been incorporated to improve system performance. Additionally, the split-lock detector control has been redesigned due to a previous kernel change that adversely affected the running of certain Steam Play games.
Linux 6.2 now supports a vast array of Qualcomm Snapdragon SoCs and Apple M1 Pro/Ultra/Max, making it the most comprehensive Linux version yet! Furthermore, this new update also features an upgraded CPUFreq driver that enables users to maximize their system’s performance potential.
Announced early this year, Spectre-BHB/BHI made a splash as an execution vulnerability similar to Spectre V2 and impacted Intel and ARM CPUs. In response, software mitigations were immediately needed for Neoverse N2 / N1 /V1 cores like Cortex-A15 / A57 72, among others. Recently released AmpereOne is not exempt either: vulnerable to the same security flaw, it now has a patch available on the Linux kernel with which one can mitigate this Spectre variant.
Linux 6.2 is receiving a major Nouveau driver update, which will bring improved NVIDIA support and unprecedented RTX 30 “Ampere” GPU acceleration – although the performance may not be as good initially.
Linux 6.2 provides essential support to Intel HuC, OA, PS64 & Sensor Monitoring for Arc Graphics; its energy sensor monitoring is enabled for DG2/Alchemist graphics through HWMON interfaces.
Intel has successfully implemented the Meteor Lake graphics support without needing a module flag, significantly influencing Intel Arc Graphics, Flex Series, and other DG2-based Intel GPUs. The stability of this process is now guaranteed, advancing current computing power to unprecedented heights!
The Linux Kernel 6.2 is packed with a multitude of DRM graphics driver updates, including FBDEV support for the “nomodeset” option and Raspberry Pi 4K @ 60Hz display compatibility.
Furthermore, the Sun4i DRM driver has added Allwinner A100 and D1 device displays to its repertoire; this ties into another new feature – the compute accelerator “accel” subsystem/framework. Together with these additions, users can expect an improved experience when using their devices!
For thorough information on the recent release, take a look at Phoronix’s feature overview for basic info or delve into further details with LWN merge report 1 and 2.
