Hello, On Mon, Jun 24, 2024 at 12:42:01PM -0400, Chris Mason wrote: ... > > - How is this supposed to work with different applications requiring > > different sched_ext schedulers? > > I'll let Tejun pitch in on this one. 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. Even for scx_layered which is the least generic in a sense, while we it's also used for a really specific ML setup internally too, what it's more widely used for is experimenting with things like soft affinity where e.g. workloads that are not latency sensitive are grouped into few hot running CPUs which are dynamically scaled to keep caches cleaner (and other effects too) for the latency sensitive parts of the system. Dan Schatzberg is trying to generalize that with scx_mitosis. So, the summry is that there are plans to support a tree of schedulers but we're currently mostly focusing on more generic single scheduler experiments. Thanks. -- tejun
