The stable Linux kernel 6.18 has been officially released, bringing many significant performance improvements and important hardware support. This new kernel is packed with features, touching everything from storage and networking to graphics support and Apple hardware.
Apple users should be happy to see massive support for Apple Silicon. Version 6.18 includes device trees for the M2 Pro, M2 Max and M2 Ultra chips. This is a big step forward in providing full mainstream Linux support for the latest generations of Apple's high-end laptops and workstations.
On the Intel side, the core also continues to provide support for the upcoming Wildcat Lake platform, including initial display and power management features, as well as new capabilities for Intel SPI serial flash. We're also seeing the unification of native haptic touchpad support, which is a fantastic quality of life feature that should make using Linux on many of today's Ultrabooks much faster.
If you're running any kind of server that deals with heavy traffic, the biggest quality of life improvement in version 6.18 will likely be the UDP ingest performance overhaul. This resulted in an additional 50 percent improvement in UDP receive performance under extreme conditions, which is a phenomenal achievement in terms of scalability.
When it comes to storage and memory, there are many key changes that developers and power users will appreciate. The XFS file system now has online file system checking, or fsck, by default.
The developers also integrated DM-PCACHE, a new persistent cache target into the Device Mapper subsystem. This allows persistent memory, such as CXL persistent memory or DAX-enabled devices, to be used as a high-performance cache layer placed in front of slower traditional block devices such as SSDs or HDDs. This should add a very noticeable speed boost on heavy I/O workloads.
Memory management has also improved significantly with the introduction of “Sheaves” in the Slub allocator. Essentially, this acts as each processor's cache for memory allocation. Because distribution can now often be done locally, it requires less synchronization with other CPUs.
The kernel also receives the first phase of the “Swap Table” infrastructure, which improves paging performance. It provides a 5 to 20 percent boost in productivity or build time, and that's not something to scoff at.
On the graphics side, the open source Nouveau driver for NVIDIA GPUs makes big changes. For Ampere and Turing cards, Nouveau now defaults to the system processor's NVIDIA GPU or GSP firmware, if available. This is a crucial step that offloads initialization and other complex tasks to the GPU itself, which should hopefully lead to much better long-term support and stability.
We're also seeing new hardware drivers, such as the Rocket accelerator driver for NPUs, found in the new Rockchip SoCs. This allows the kernel to handle that particular processor.
Kernel security and future development opportunities are also attracting attention. The release added the ability to load BPF programs that have a cryptographic signature. This is a fundamental step towards allowing non-privileged users to download verified BPF programs, thereby increasing security.
There will also be Tyr, a new Rust DRM driver for Arm Mali GPUs that will eventually replace the existing Panthor driver. It's great to see the Rust language continue to evolve in the core ecosystem.
Linus Torvalds confirmed that the release process went fairly smoothly, even with a slight increase in bug fixes at the end. Now that version 6.18 is out, the merge window for Linux 6.19 is already open. Given the timing, the 6.19 release cycle will likely be delayed due to the holiday season, but for now, 6.18 is here and it looks like a solid and feature-rich LTS contender.
Source: Linux kernel mailing list by using Phoronix
