How To Install Kernel 6.9 On Ubuntu, Debian And Derivative Systems

The Linux kernel is the core component of any Linux operating system, managing hardware resources and system processes.

In this guide we will be installing Kernel 6.9, which has been released a while go, coming with changes.

Kernel 6.9 highlights:

AMD P-State ‘Preferred Core’ Support: The AMD P-State driver now supports ‘preferred cores’ on AMD Zen 2 and later processors, allowing the Linux scheduler to assign high-priority tasks to cores capable of higher maximum frequencies.
Intel Fastboot Enabled for Pre-Skylake Chips: Intel Fastboot, which reduces boot times by minimizing unnecessary mode-sets during startup, is now enabled for chipsets older than Skylake, resulting in faster boot experiences across a broader range of hardware.
CPU Timer Code Overhaul: Significant updates to the CPU timer code have been implemented, leading to performance improvements in network-centric workloads and enhanced power management, including the ability to completely power down a die in multi-die sockets during idle scenarios.
Workqueue Code Enhancements: The workqueue subsystem has undergone substantial changes to address issues from previous kernel versions, improving system efficiency and task scheduling.
KVM Virtualization Improvements: Kernel-based Virtual Machine (KVM) enhancements include better performance in emulated event triggering and during forced immediate exit scenarios, benefiting virtualization workloads.
EXT4 Case-Insensitive Handling Optimization: Performance improvements in case-insensitive file and folder handling for the EXT4 filesystem have been introduced, with the kernel attempting case-sensitive comparisons first before falling back to case-insensitive lookups.
Intel Atom CPU Vulnerability Mitigation: A hardware vulnerability in Intel Atom CPUs has been addressed, preventing potential malicious actors from inferring data values previously used in various registers.

Device-Specific Enhancements:

Fujitsu Laptops: Battery charge control support has been added.
HP Omen 17: Performance improvements are available, with an option to manage increased power draw and heat generation.
Lenovo IdeaPad: Support for the ‘refresh rate’ key to adjust display refresh rates.
Microsoft Surface: Fan speed control capabilities have been integrated.
Lenovo ThinkPad: The ACPI driver now supports additional ‘Fn’ keys.

Samsung Wireless Device Support: Out-of-the-box support for various Samsung wireless devices, including certain keyboards, game controllers, and the Galaxy Book Cover, has been added.

Xbox Controller Compatibility: The Xpad driver now supports third-party Xbox controllers, specifically the Snakebyte GAMEPAD BASE X and GAMEPAD RGB X models, enhancing the gaming experience on Linux.

In this guide we will be installing Kernel 6.9, which has been released a while go, bringing some fixes and enhancements only.

Check your current kernel version:

Before proceeding with the installation, verify your current kernel version by running:

uname -r

How to install Kernel 6.9 on Ubuntu, Linux Mint, Debian, and derivative systems (amd64/x86_64):

Step 1: Update Your System

Run the following commands to ensure your system is up to date:

sudo apt update && sudo apt upgrade -y

This will update your package list and upgrade all installed packages to their latest versions.

What Does apt update Do?
This command updates the package list to reflect the latest versions available from your repositories.
What Does apt upgrade Do?
It upgrades all the packages that have new versions available while keeping existing dependencies intact.

Step 2: Download the Kernel 6.9 Packages

Download the necessary kernel packages from the official Ubuntu repositories or the kernel website:

wget -c https://kernel.ubuntu.com/mainline/v6.9/amd64/linux-headers-6.9.0-060900-generic_6.9.0-060900.202501291528_amd64.deb
wget -c https://kernel.ubuntu.com/mainline/v6.9/amd64/linux-headers-6.9.0-060900_6.9.0-060900.202501291528_all.deb
wget -c https://kernel.ubuntu.com/mainline/v6.9/amd64/linux-image-unsigned-6.9.0-060900-generic_6.9.0-060900.202501291528_amd64.deb
wget -c https://kernel.ubuntu.com/mainline/v6.9/amd64/linux-modules-6.9.0-060900-generic_6.9.0-060900.202501291528_amd64.deb

Step 3: Install the New Kernel

Install the downloaded packages using dpkg:

sudo dpkg -i linux-headers-6.9*.deb linux-modules-6.9*.deb linux-image-6.9*.deb

Step 4: Update GRUB and Reboot

Once the kernel installation is complete, update GRUB to ensure the new kernel is recognized:

Regenerate the GRUB Configuration

Run the following command to update GRUB with the latest installed kernel:

sudo update-grub

Verify GRUB Configuration

To confirm that the new kernel has been detected, check the GRUB configuration:

cat /boot/grub/grub.cfg | grep 'menuentry'

This should list all available kernels, including Kernel 6.9.

Reboot the System

Restart your computer to apply the changes:

sudo reboot

Select the New Kernel (if needed) – If the system doesn’t automatically boot into the new kernel, you can manually select it:
- Hold Shift or Esc during boot to access the GRUB menu.
- Navigate to Advanced options for Ubuntu.
- Choose the entry with Kernel 6.9.
- Press Enter to boot.

Verifying the Installed Kernel

After rebooting, confirm the new kernel version:

uname -r

Rolling Back to a Previous Kernel

If you encounter issues with the new kernel, you can revert to an older version:

Reboot and Access the GRUB Menu -Restart your system and hold Shift or Esc to enter the GRUB boot menu.
Select Advanced options for Ubuntu – Choose an older kernel version and boot into it.
Remove Kernel 6.9 (if desired) – If you prefer to remove the new kernel permanently, run:

sudo apt remove linux-headers-6.9* linux-modules-6.9* linux-image-6.9*
sudo update-grub
sudo reboot

Conclusion

Linux Kernel 6.9 is a significant update that brings numerous improvements across performance, security, and hardware compatibility. The introduction of Intel Fastboot by default and enhancements to AMD P-State for better power efficiency make this release particularly appealing for users on modern hardware, ensuring improved performance and energy savings.

The updated CPU timer code and KVM optimizations contribute to better power management and virtualization performance, which will be beneficial for enterprise workloads and server environments. Additionally, the kernel update includes important security fixes, such as mitigations for Intel Atom CPU vulnerabilities, ensuring a more secure computing experience.

For hardware compatibility, support for various devices and peripherals has been expanded. Fujitsu laptops, Fujitsu tablets, Lenovo IdeaPads, HP laptops, Microsoft Surface devices, and certain Xbox controllers now have improved Linux support, enhancing the user experience for a broader audience.

Overall, Linux Kernel 6.9 continues the tradition of iterative refinements, bringing notable advancements in CPU power management, filesystem optimizations, and driver support. These updates make the kernel more efficient, secure, and compatible with a wider range of modern hardware, solidifying its position as a versatile and performance-oriented operating system for both desktop and enterprise users.