Linux kernel 6.9 has been released after several months of delay on May 12, 2024. Linus Torvalds announced this via the Linux kernel mailing list on this post.
The Linux 6.9 release introduces support for AMD P-State ‘preferred core’ in the AMD P-State driver for AMD Zen 2 and newer processors. These preferred cores are capable of reaching a higher maximum frequency compared to other cores. With this kernel support, the Linux scheduler can allocate high-priority tasks to these specific cores.
Linux kernel 6.9 also incorporates support for the Named Address Spaces feature within GCC (GNU Compiler Collection). This enhancement enables the compiler to optimize per-CPU data access more effectively. Moreover, the kernel now includes initial support for FUSE passthrough, enabling it to directly serve files from a user-space FUSE server. Additionally, the kernel introduces the ability to dynamically update the Energy Model at runtime. Furthermore, a new LPA2 mode is introduced specifically for ARM 64-bit processors.
The F2FS (Flash-Friendly File System) now supports zoned block devices, per-file compression, and enhanced data recovery following sudden power loss on zoned block devices. Additionally, the exFAT file system has improved directory synchronization performance. The EXT4 file system now includes an inode flag for atomic writes and enhancements to online resizing. Furthermore, the Btrfs file system has received additional fixes for zoned mode and minor performance optimizations.
Moreover, improvements have been made to memory management performance, and the perf tool has been enhanced with several new features. BPF token support has been introduced to delegate a subset of BPF subsystem functionality from privileged system-wide daemons such as systemd. Additionally, initial support has been added for the contiguous PTE bit on ARM 64-bit processors, enabling TLBs to map a range larger than a single PTE if the range is physically contiguous.