Canonical, the maker of Ubuntu Linux, is making a major change to its kernel strategy, with plans to use the latest version available at the time of a new release.

Canonical’s Brett Grandbois pointed out that Ubuntu and the Linux kernel’s developers follow two different release schedules. As a general rule, the Canonical Kernel Team (CKT) likes to have a month from the time the kernel developers release a new version to when they view it stable enough to incorporate it into Ubuntu.

Given the non-aligned nature of the two release schedules, it is inevitable that there will be instances where both release dates happen to fall on or near the same date. This can be further exacerbated by the nature of the upstream kernel releasing when it is deemed ready, not at some predetermined deadline, which therefore could mean a much later release date than originally anticipated. A general rule of thumb, that the CKT has determined, is that about a month is required between an upstream release and the associated Ubuntu kernel to be considered stable enough for release. That can pose a problem when the upstream release is expected to land either within the 4 weeks before the Ubuntu release or even a few weeks after the Ubuntu release is scheduled.

As Grandbois points out, this can create issues for the CKT when release schedules force the team to either adopto a brand-new kernel that hasn’t been fully tested, or an older one that’s already superseded.

This puts the CKT in a bit of a dilemma. Does Ubuntu release with a 2-3 month old upstream kernel that will likely be superseded on or near the release date? Or should the qualification period be shortened to make the release date, possibly with a lower confidence in stability? Or should the Ubuntu release date be adjusted accordingly, even with prior commitments made?

Moving forward, Grandbois says the CKT will adopt the newest available kernel, even if it’s not the final version.

The intent behind this post is to describe a new policy the CKT is taking in regards to kernel version selection for an upcoming Ubuntu release. To provide users with the absolute latest in features and hardware support, Ubuntu will now ship the absolute latest available version of the upstream Linux kernel at the specified Ubuntu release freeze date, even if upstream is still in Release Candidate (RC) status.

As a result of the change, Grandbois says the CKT will only be able to announce the kernel version for the next upcoming release, rather than being able to announce the planned kernel version for subsequent releases as well.

This is to be the kernel selection policy for all future Ubuntu releases, hence the description of LTS situations as well as the Interim 24.10 release.

With this policy we will be able to be more aggressive about making kernel version commitment announcements for an upcoming release at a much earlier date than previously. However, due to the uncoupled nature of the upstream and Ubuntu releases as described above the CKT will only be able to announce the kernel version for the next upcoming release, not any successive ones.

The new strategy should help users with newer hardware, providing them with the latest kernel and drivers out of the box. In contrast, current users often have to install a kernel that is slightly out-of-date, and then update it if it doesn’t fully support their hardware.

Given Canonical’s commitment to maintaining and supporting the kernel versions it uses, the change shouldn’t result in significant downsides for users.