Linux 6.9-rc1 provides a glimpse into the future of the open source kernel

Linus Torvalds has officially announced the release of Linux 6.9-rc1, marking the end of the merge window for this version. As usual, the update brings a ton of changes, with a significant portion attributed to AMD GPU header files. But let's not get bogged down by the sheer volume of these updates; the real excitement lies in the core improvements that promise to enhance the kernel's performance.

Two major updates steal the spotlight in this release: the timer subsystem and the workqueue subsystem. The timer subsystem has undergone a substantial rewrite, introducing per-CPU timer wheels. This enhancement is poised to boost the performance of timers, which is especially crucial for networking operations. On the other hand, the workqueue subsystem now supports BH workqueue support, providing a much-needed alternative to the long-deprecated tasklet interface.

These core updates are designed to be invisible to end-users, focusing solely on expanding the kernel's capabilities without altering its semantics. However, they're significant enough to have caused a few hiccups during development, which have presumably been ironed out by now.

Apart from the core updates, Linux 6.9-rc1 is packed with the usual suspects: driver updates, architecture tweaks, filesystem adjustments, and networking enhancements. Notably, the old NTFS core has been removed, marking the end of an era and the beginning of a more streamlined kernel.

One of the highlights of this release is the vast array of contributors, with updates spanning from VFIO and RTC to SCSI, power management, and sound. This collaborative effort underscores the diverse and dynamic nature of the Linux kernel development community.

Linus Torvalds has put out a call for testing, urging the community to dive into the new release and ensure its stability and performance. As the kernel continues to evolve, community involvement remains a crucial part of its development process.