Linus Torvalds announced the release candidate 4 (RC4) of the upcoming Linux kernel version 6.15. Linus expresses a generally positive sentiment regarding this release candidate. He also seems quite pleased with how things are shaping up.
In the Kernel 6.15-rc4 release announcement, he noted that things appear "pretty normal" and there were no significant last-minute issues caused by system upgrades.
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That Pesky Locking Issue is Sorted!
Did you aware of the locking mishap with something called local_trylock that Phoronix reported? Well, great news – it's been sorted out!
Apparently, this issue didn't pop up for everyone depending on the compiler they were using, but it's been squashed now, which is crucial for avoiding potential headaches with how the kernel manages things internally.
Focus on Future Changes
Torvalds noted that a lot of the current discussions among developers are actually focused on "future changes". He considers this a "good sign," implying that the current state of the kernel is relatively stable and allows developers to think ahead.
A Pretty Flat Report Card
Looking at the technical bits, the rc4 diffstat (basically a summary of all the changes) is described as "pretty good - mostly flat". This means there haven't been a massive number of huge changes this week.
The main things that stand out are some "untimely, but still fairly small" updates for OpenRISC (an open-source processor architecture) and patches for bcachefs case-insensitivity.
The rest of the updates are characterised as "a lot of tiny fixes," but nothing out of the ordinary for this stage of the release cycle.
Key Improvements in Kernel 6.15-rc4
There's still a good chunk of work that's gone into this RC4 release. The commit log shows a wide range of fixes and minor improvements across different parts of the kernel.
Here are some of the key areas that have seen attention:
Driver Updates and Fixes
This is always a big one! Lots of work has been done to improve support and fix issues for various hardware. This includes:
- USB: Adding support for new gadgets like the Sierra Wireless EM9291 and the OWON HDS200 series oscilloscope. There are also fixes for potential crashes and quirks for specific USB devices. Issues related to power management and mobile broadband devices have also been addressed.
- Networking: Plenty of fixes for specific network card drivers like stmmac, mt7530, dp83822, enetc, and mlx5. There are also important fixes for potential security vulnerabilities in traffic control and general improvements in other networking components.
- Graphics (DRM): If you're using Exynos, AMD, or Meson graphics, there are fixes in this release related to display drivers. These include addressing things like spelling errors (I didn't kernel code has typos!), calculation issues, and how the system handles display information.
- Storage: A significant amount of work continues on bcachefs, including the exciting addition of case-insensitivity support. There are also numerous other fixes for bcachefs related to startup, errors, internal checks, and how it manages data. Other filesystems like XFS, btrfs, ceph, and ext4 have also received bug fixes and improvements.
- CPU Frequency (cpufreq): Fixes have been implemented to prevent potential crashes in drivers for Apple, SCMI, and SCPI CPUs.
- Other Core Bits: Many smaller fixes and improvements have been made to other fundamental parts of the kernel like I2C, serial communication, PCI devices, how the system manages memory, and more.
Kernel Virtual Machine (KVM) Enhancements and Fixes
For those who use virtual machines with KVM, there are several improvements and bug fixes related to how it handles interrupts and other internal mechanisms.
Filesystem Fine-Tuning
Beyond the big bcachefs changes, other filesystems have seen attention, mostly in the form of bug fixes to improve stability and reliability.
Security
The Landlock security module, which helps with sandboxing applications, has received several fixes and improvements.
Continued Support for LoongArch
Work continues to refine support for the LoongArch processor architecture with various fixes.
Driver Core Improvements
A new helper function called device_set_driver() has been introduced, and there are fixes for potential issues when handling device events.
Build and Testing
Minor tweaks and additions have been made to the kernel's self-testing framework and build configurations.
Try Linux Kernel 6.15 RC4
While things are looking positive, Torvalds still recommends everyone to "keep testing". He specifically mentions that the "untimely" OpenRISC updates and the bcachefs case-insensitivity patches might need a closer look to ensure they haven't introduced any new problems.
You can download the latest Linux Kernel 6.15 RC4 from the Kernel.org website or the Linus Torvalds's git tree.
As always, the journey isn't over until the final release, but for now, things seem to be on the right track. Keep an eye out for more updates as we get closer to Linux Kernel 6.15!
