Re: [PATCHSET v6] sched: Implement BPF extensible scheduler class

Peter Oskolkov
2024-06-24T22:01:14Z

On Mon, Jun 24, 2024 at 11:11 AM Tejun Heo <tj@kernel.org> wrote:
[...]
> > > - How is this supposed to work with different applications requiring
> > > different sched_ext schedulers?
[...]
> Long term, the tentative plan is to support a hierarchy of schedulers where
> the intermediate schedulers are responsible for granting CPUs to leaf
> schedulers which are responsible for scheduling tasks. Barret Rhoden has a
> framework called flux on top of ghost which already implements this albeit
> with compile time composition. Nothing is set in stone yet but it's likely
> that I'll follow what Barret is doing in many parts.
>
> Taking a step back, because sched_ext currently supports a single
> system-wide scheduler, many of the techniques that the current crop of
> schedulers are playing with are pretty generic, at least to a class of
> problems - e.g. gaming.

[...]

> So, the summary is that there are plans to support a tree of schedulers but
> we're currently mostly focusing on more generic single scheduler
> experiments.

[...]

Yes, as I've just mentioned in another message in this thread, we plan
to explore building UMCG-like per-process scheduling infra on top of
sched_ext once it is merged into the mainline kernel. This is not a
promise to actually do that (build such an infra); but rather a claim
that we believe it is possible to do that and that we plan to look
into the technical details once sched_ext is merged.