Linux Kernel 6.5 is finally released with many new features and improvements. Let’s take a quick look at the new features.
Linus Torvalds released Linux Kernel 6.5, which is the latest mainline Kernel at the moment. You can try out to get the updated fixes and hardware support. After a smooth and quiet testing window, Linux Kernel 6.5 is now available to download.
The key items of this release are the support for modern CPU and GPU lineups, WiFi 7 support and a whole lot of performance improvements.
So nothing particularly odd or scary happened this last week, so there is no excuse to delay the 6.5 release.
I still have this nagging feeling that a lot of people are on vacation and that things have been quiet partly due to that. But this release has been going smoothly, so that’s probably just me being paranoid. The biggest patches this last week were literally just to our selftests.
Linus
Let’s briefly take a look at what’s new.
Table of Contents
Linux Kernel 6.5: What’s New
Processors
Exciting news for users of high-core count Intel Xeon, AMD EPYC, and higher-core HEDT processors. This release is bringing parallel CPU boot support aimed at significantly reducing kernel boot times. This feature will greatly benefit large core count servers, enabling faster boot times, particularly when employing Kexec for seamless kernel version updates.
AMD engineers have been diligently addressing system suspend/resume issues, particularly concerning Ryzen laptops, to enhance reliability. By rectifying a missing check in the USB XHCI driver, a mere one-liner adjustment, they managed to shave off an additional 120ms during system resume time. Though seemingly small, this optimization holds significance within the broader context of AMD’s ongoing efforts to optimize the Linux experience on their Ryzen platform. So, if you are using Ryzen laptops, you might see faster resume time with this Kernel version via various Linux distributions.
With recent additions to the amd64_edac Linux kernel driver, Ryzen 7000 series desktop processors will now receive similar treatment to the EPYC 9004 series in terms of EDAC reporting. This includes ECC error reporting for supported RAM/motherboard configurations.
AMD’s open-source Linux graphics driver team has recently introduced a noteworthy set of patches for their display code, specifically the “DC” codebase within the AMDGPU kernel graphics driver. With the upcoming release of the Linux 6.5 kernel, these patches will bring another attempt at enabling FreeSync Video as the default setting. Previously, there were concerns regarding hang and corruption problems on eDP panels. However, with the latest patches, these issues have been successfully resolved, providing confidence in enabling this feature by default out-of-the-box.
The ASUS ROG CROSSHAIR X670E Hero motherboard sensor monitoring is now available in Linux Kernel 6.5. This is marketed as the high-end motherboard for AMD Ryzen 7000 series / AM5 processors.
More updates and work is complete for the Intel Hybrid CPUs with hyperthreading.
Intel Continues Prepping Meteor Lake Graphics On Linux, Adds VRR eDP Support
Intel continues to push the numerous support for the Meteor Lake graphics, and this release includes variable refresh rate eDP support and HuC loading support.
Storage
The NTFS3 file-system driver, which was upstreamed in 2021 for Linux 5.15, brought significant improvements over the previous NTFS kernel driver and NTFS-3G FUSE driver. Since its initial release, the driver has undergone continuous enhancements to further enhance its capabilities.
With the upcoming Linux 6.5 release, the NTFS3 driver now includes support for volinfo and label attributes, making them accessible under sysfs for NTFS volumes. Additionally, an alternative boot mode has been added to handle corrupted primary boots, along with several optimizations implemented throughout the kernel driver codebase.
The Flash-Friendly File-System (F2FS) has received a few enhancements and new features for this release. One of the key focuses in this development cycle has been the investigation of zoned block device support. Various patches have been introduced to address issues such as rectifying write pointers between f2fs and storage, implementing an asynchronous zone reset flow, and managing the number of open zones. Additionally, F2FS introduces a new mount option, “errors=x,” which allows users to specify how to handle unexpected behaviours detected during runtime. This feature provides flexibility in managing and responding to unforeseen issues encountered while using F2FS. Overall, these improvements contribute to the ongoing optimization and reliability of the Flash-Friendly File-System for Linux users.
In Linux Kernel 6.5, EXT4 will experience significantly improved performance in parallel direct I/O (DIO) overwrites. Brian Foster from Red Hat has contributed to this optimization, enabling concurrent unaligned DIO overwrites and yielding remarkable performance gains. With this patch, his test case using FIO demonstrated a substantial increase from 8724 KiB/s to 1565 MiB/s.
Ports and drivers
MIDI 2.0, a significant update to the widely-used MIDI protocol for musical devices, brings notable enhancements such as higher resolution, improved articulation, and the Universal MIDI Packet (UMP) for streamlined transmission of multiple MIDI messages. Linux Kernel 6.5 brings complete MIDI 2.0 support with better driver coverage and compatibility.
The upcoming Linux Kernel 6.5 is set to include improvements to the Broadcom VC4 DRM driver, particularly in relation to HDMI controllers. These enhancements, which were previously only available in the downstream Raspberry Pi kernel, are now being upstreamed to the mainline tree. Notable features include the introduction of a Broadcast RGB property, allowing users to override the HDMI pixel range if the monitor’s data is inaccurate. Additionally, the support for BT.601 and BT.2020 colorspaces, with the latter being significant for Ultra HD TVs with standard dynamic range, is being added.
Virtualization and networking
UEFI Unaccepted Memory support has been successfully merged into Linux 6.5, providing crucial backing for industry standards such as Intel Trusted Domain Extensions (TDX) and AMD Secure Encrypted Virtualization Secure Nested Page (SEV-SNP) backed virtual machines.
Among the various RISC-V KVM improvements for Linux 6.5, the standout feature is the successful implementation of guest snapshot support for KVM guests. This enhancement allows RISC-V KVM guests to benefit from functional live snapshot support for virtual machines, enabling efficient management and operation of VM snapshots.
The networking subsystem changes in the Linux 6.5 kernel encompass several advancements related to the evolving WiFi 7 wireless standard, as well as the inclusion of support for various newer network adapters.
So, that’s about the key changes. As always, the entire changelog is huge for the release, and you should get a release diff after the final release.
How to Download and Install Linux Kernel 6.5
Remember that using the bleeding-edge mainline Linux Kernel in your production systems/daily-drive laptops/desktops is not wiser unless you have a specific requirement.
For general users, it’s always best to wait for a few weeks until all the major Linux Distributions bring this version via their official stable channel after proper testing.
That being said, if you still want to install this version, follow the instructions below in Debian-based distributions, which I lined up here.
- Firstly, visit the mainline kernel page
- There are two types of builds available – generic and lowlatency. You can download generic builds that work most of the time for standard systems.
- For audio recordings and other setups that require low latency (like real-time feeds), download the lowlatency one.
- Secondly, download the four deb packages for generic via the terminal and install them.
wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v6.5/amd64/linux-headers-6.5.0-060500-generic_6.5.0-060500.202308271831_amd64.deb wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v6.5/amd64/linux-headers-6.5.0-060500_6.5.0-060500.202308271831_all.deb wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v6.5/amd64/linux-image-unsigned-6.5.0-060500-generic_6.5.0-060500.202308271831_amd64.deb wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v6.5/amd64/linux-modules-6.5.0-060500-generic_6.5.0-060500.202308271831_amd64.deb
sudo dpkg -i *.deb
- After installation, reboot the system.
- The instruction for lowlatency and other architecture (e.g., ARM) installations are the same. Replace the package name in the above wget commands. You can find them on the mainline Kernel page.
Distro support
Arch Linux users should get this version by 1st/2nd week of September-2023 via monthly ISO refresh.
Ubuntu 23.10 may feature this Kernel by the end of this year. Also, Fedora 39 may feature this version which is due by Q4 2023.
Wrapping up
To sum up, the release of Linux Kernel 6.5 introduces numerous important updates and enhancements, such as updates to CPU and GPU, ARM and SoC, core changes, and improvements to file systems and networking. These new features and updates will offer users the opportunity to elevate their computing experiences with the most current version of Linux Kernel.
