I find this somewhat amusing given one of the primary use cases of eBPF is measuring performance
Network routing can be implemented in (e)bpf. It's even the original use case.
But there's also the LSM based on ebpf, there's a user space scheduler (Google iirc), seccomp and some cgroup filters can be done in bpf...
It's the Lua of the kernel at this point. Provides a lot of extension points.
also one from canonical in rust on top of scx https://github.com/sched-ext/scx/tree/main/scheds/rust/scx_r... https://arighi.blogspot.com/2024/02/writing-scheduler-for-li...