Growing major version

Posted Feb 13, 2026 20:10 UTC (Fri) by jmalcolm (subscriber, #8876)
In reply to: Growing major version by alx.manpages
Parent article: The first half of the 7.0 merge window

> Eventually, we'll have a large major version number, and there's nothing that could fix that

That is true, but the major version numbers change much less often. So, it is not really that hard to keep track of them. And I can keep track of recent minor versions but I agree with Linus that they all start to run together after a while.

Linux kernel version 6 was released about three years ago with version 5 about three years before that. Even if it were 156 currently and 155 three years ago, I think I could tell you the current major version number of Linux and, if you gave me a previous one, I would have a sense of how old it was. I would also have a pretty good idea of the major features that appeared in each one.

Without looking it up, I can say that Linux kernel 5 brought the introduction of Apple Silicon, io_uring, and exFAT. Apple Silicon then matured very nicely in Linux kernel 6 which aligns with the experimental period for "Rust in the Linux kernel". The major new architecture in kernel 6 has been RISC-V which is maturing nicely but, like Rust, will probably hit its stride in kernel 7. Kernel 6 also contained the bcachefs saga and the long-awaited real-time merge. Kernel 6 aligns with when most people started to trust btrfs (I still don't). We do not even have 7 and it already feels like it will be the release where both Rust and RISC-V go mainstream. Maybe bcachefs will come back. If not, perhaps a competitor. In short, the major version numbers seem meaningful in terms of marking different eras of kernel evolution.

I can tell you that "Docker containers" appeared in the kernel 4 timeframe but that you really need at least kernel 5 to run Docker today.

Contrast that to the situation where we had 2.6 forever and there was 2.6.38.8 and 2.6.25.20 three years before that (had to look that up just now). Without checking the date, could you have told me in rough terms how old the latter was or what had changed since then? Not me.

And kernel 2.4 goes all the way back to the Windows XP days. It feels like the beginning of 2.4 and the end of 2.6 is half the history of Linux.

The current system works pretty well in practice.