Bump minimal supported Linux kernel version

[florianl]

On a regular base the question is asked to bump the supported Linux kernel version for various reasons and to various versions.

This issue is about figuring out a policy, on when the minimum Linux kernel version should be bumped.

At the time or writing (2026-02-16), the minimal supported Linux kernel version is 5.4 for amd64 and 5.5 for arm64.

Ecosystem overview

OS	Kernel Version	Support until	Information source
Debian 11	5.10	LTS until 2026-09	https://en.wikipedia.org/wiki/Debian_release_version_history
Redhat 9	5.14		https://access.redhat.com/articles/red-hat-enterprise-linux-release-dates
Ubuntu 20.04 LTS	5.15	LTS until 2030-04	https://ubuntu.com/kernel/lifecycle
Amazon Linux 2	5.10		https://docs.aws.amazon.com/linux/al2/ug/aml2-kernel.html

On https://kernel.org/ the "oldest" supported LTS kernel is 5.10.250 and will likely get supported until December 2026.

Suggestion

The minimal supported Linux kernel version should correspond to the lowest version used by the established operating systems detailed in the ecosystem overview.

[fabled]

We also get occasionally requests to support older versions. Likely due to RedHat having support for 10 years.

RHEL 8: Released May 2019; Full Support until May 2024; Extended Life Phase ends May 31, 2031.

RHEL 7: Ended Full Support Aug 6, 2019; Extended Life Phase ends May 31, 2029.

But both are out of scope as they have older kernels than what we support currently.

Also noted that RedHat backports features to their kernels so their announced kernel version is not directly comparable to vanilla kernel version.

But agreeably to move forward it makes sense to bump up the minimum kernel version requirement. The new kernel features often allows optimizing the ebpf code in several ways.

But otoh the minimum requirement depends on what features we actually need/want to use.

It might make sense to revive the list of useful new kernel features that we could use, and put the minimum requirement for it. That might help on assessing the point.

[florianl]

I did not list RHEL 7 and 8 as eBPF profiler already use a newer minimal Linux kernel version, than these OS officially support. But as RH backports Linux kernel features, it might be possible to run eBPF profiler.

If the above suggested policy is applied, this would bump the minimal supported Linux kernel version to 5.10. Consequently, the minimal version for amd64 and arm64 would be aligned and the project could benefit from the following features:

feature	support in Kernel	commit	comment
Unify batch operations	5.6	torvalds/linux@cb4d03a, torvalds/linux@aa2e93b, torvalds/linux@0579963	Currently this is partly supported using probes at runtime
BPF_FUNC_read_branch_records	5.6	torvalds/linux@fff7b64	This could help resolve native_stack_delta_invalid errors
BPF_FUNC_get_ns_current_pid_tgid	5.7	torvalds/linux@b4490c5	This could help resolving issues like #620 (comment)
Ring buffer	5.8	torvalds/linux@457f443	Ring buffer are the sucessor to perf event maps
Mixing bpf2bpf calls and tailcalls	5.10 for amd64 and 6.0 for arm64	torvalds/linux@e411901, torvalds/linux@d4609a5	This could allow to simplify and restructure eBPF programs
BPF trampoline	5.5	torvalds/linux@f1b9509	Make use of BPF_TRACE_FENTRY/BPF_TRACE_FEXIT

[DanielShaulov]

Note that 5.6 also adds function-by-function verification.
If we replace tail_call usage with bpf2bpf, I think 5.6 is enough and we don't need 5.10/6.0

[florianl]

My suggestion is to bump Linux kernel versions to the lowest version used by an established set of operating systems, to avoid opening the discussion around every Linux kernel minor version.

[fabled]

5.10 supports mixed inner map sizes. See https://github.com/open-telemetry/opentelemetry-ebpf-profiler/blob/main/doc/KNOWN_KERNEL_LIMITATIONS.md#ebpf-inner-arrays-map-in-map-must-be-of-same-size

That would be a great win.

[florianl]

My idea going forward with this is, to get the policy on this topic merged first - see #1259 - and then open a new PR that will bump the minimum required Linux kernel version to 5.10.