I am leveraging the new Sched-ext capability in the kernel to write an ebpf scheduler using C. I have two sets of CPUs: the fast group and the slow group. When a task first arrives, it’s scheduled on one of the fast CPUs (using the select_cpu callback.) And it’s given a 100ms slice (using scx_bpf_dispatch) to run on this CPU.
If this slice is exhausted the first time, I want this task to be taken off this CPU and rescheduled to another cpu in the slow group. What helper function in ebpf and scx can I use to do so? I can’t find anything that could take a task off a local dsq once it has been inserted there.