Linus Torvalds Throws Down The Hammer: Extensible Scheduler "sched_ext" In Linux 6.11

The extensible scheduler "sched_ext" code has proven quite versatile for opening up better Linux gaming performance, more quickly prototyping new scheduler changes, Ubuntu/Canonical has been evaluating it for pursuing a more micro-kernel like design, and many other interesting approaches with it. Yet it's remained out of tree but that is now changing with the upcoming Linux 6.11 cycle.

Linus Torvalds as the benevolent dictator for life "BDFL" of the Linux kernel announced he intends to merge the sched_ext patches for Linux 6.11 even though there has been some objections by other kernel developers. Torvalds feels the sched_ext code is ready enough and provides real value to the mainline Linux kernel. It's not worth dragging out sched_ext continuing to be out-of-tree.

Torvalds used his authority today on the Linux kernel mailing list thread around the sched_ext v6 patches to announce his intent to merge the code with Linux 6.11:

"I honestly see no reason to delay this any more. This whole patchset was the major (private) discussion at last year's kernel maintainer summit, and I don't find any value in having the same discussion (whether off-list or as an actual event) at the upcoming maintainer summit one year later, so to make any kind of sane progress, my current plan is to merge this for 6.11.

At least that way, we're making progress, and the discussion at KS 2024 can be about my mental acuity - or lack thereof - rather than about rehashing the same thing that clearly made no progress last year.

I've never been a huge believer in trying to make everybody happy with code that is out of tree - we're better off working together on it in-tree.

And using the "in order to accept this, some other thing has to be fixed first" argument doesn't really work well either (and _that_ has been discussed for over a decade at various maintainer summits).

Maybe the people who have concerns about this can work on those concerns when it's in-tree.

I'm also not a believer in the argument that has been used (multiple times) that the BPF scheduler would keep people from participating in scheduler development. I personally think the main thing that keeps people from participating is too high barriers to participation.

Anyway, this is the heads-up to Tejun to please just send me a pull request for the next merge window.

And for everybody else as a "It's happening" heads-up."

So short of any last minute change of plans between now and mid-July when the Linux 6.11 merge window opens, looks for sched_ext in the next kernel cycle.