Rocky Linux kernel naming convention

Rocky Linux Tech Help
1

Could any expert explain the naming convention of Rocky Linux kernel?
Take Rocky Linux 8.8 as example: the kernel version is 4.18.0-477.10.1.
My understand:
4: Major version
18: Minor version
0-477: ?
10: ?
1: ?
I don’t know 0-477, 10 and 1’s naming.
Could any expert help clarify?
Thanks in advance!

2

The kernel version starts out as a normal kernel version that you would see from kernel.org. Also read about semantic versioning.

4: Major version
18: Minor version
0: Micro/Patch version
1-553.X.Y: Package Release version

Replace X and Y accordingly.

3

Thanks a lot for your quick clarification!

4

When will the Red Hat Enterprise Linux package be updated to the upstream version? - Red Hat Customer Portal does also tell about the versioning.
The main points:

At the time that a RHEL major version is released, a particular version of each of the software component has been selected …

During the lifecycle of a RHEL major release, bug/security fixes and feature enhancements are backported from upstream projects to RHEL packages.

For example, if a RHEL release includes package version software-2.10 of a particular piece of software, Red Hat changes will likely follow a numbering scheme like software-2.10-1 then software-2.10-2 then software-2.10-3 and so on. Even if upstream change the software to software-2.11, the RHEL package will likely remain on software-2.10-n and features/fixes from the later upstream releases may be backported into the RHEL software-2.10-n packages and the RHEL-specific version suffix will increase.

You can look at changelog of (installed) package with:

rpm -q --changelog kernel-4.18.0-477.10.1* | less

You can also list the kernels that you have at some point installed:

dnf history info kernel | grep Install.*kernel-4

Lets generalize the “4.18.0-477.10.1” into “X.Y.Z-A.B.C” (the A.B.C is Package Release version). For RHEL 8 (and hence Rocky 8) kernel, the X.Y.Z does not change – always 4.18.0.
The A increases as features are backported. It remains constant within point update. The el8_0 had A=80, the el8_8 had A=477, and el8_10 has A=553. Bug and security fixes released for point updates’ kernel are in the B.C.

2 Likes
5

Thanks a lot for the detailed clarification!
It helps a lot.
One more query, for such kernel Package Release version update from 4.18.0-477 to 4.18.0-553 (OS update from 8.8 to 8.10)， will there be any performance impact (especially performance degrade)?

6

I think you have already seen answer to that in How to get the kernel changes between Rocky Linux 8.8 and 8.10 - #6 by nazunalika

Overall, Red Hat has RHEL major version X that is at point update Y. For example, RHEL 8.9.
Red Hat has paying customers; they sell support subscriptions for RHEL 8.
They did release new point update, Y+1 – RHEL 8.10. An assumption is that most users auto-upgrade 8.9 → 8.10. It would not be good for business to introduce performance degradations, would it? (Workarounds to security issues may cause some degradation, but not on every update.)

7

Yes, I see the answers. I ask again here in case if you have different understanding and insight.
Anyway, you clarification is very helpful. Thanks a lot!