Re: [PATCH v2 sched_ext/for-7.3 4/4] sched_ext: Split sub-scheduler implementation into sub.c

[Tejun Heo <tj@kernel.org>]

Hello,

> - [Low] Compilation failure due to implicit function declarations in `sub.h`.

Yeah, scx_dispatch_sched() moved into sub.h calls three ext.c statics whose
declarations only land in a later patch, so 4/4 doesn't build on its own.
Another series-slicing mistake on my end. Will fix and post v3.

> - [High] The `scx_bpf_sub_dispatch` kfunc breaks runqueue lock atomicity for the parent BPF program.

ops.dispatch has never held the rq lock across its whole execution, and
scx_bpf_dsq_move_to_local() already drops and reacquires it when consuming a
remote task, so there's no continuous-lock guarantee to break.

> - [High] Missing `scx_error()` calls in `scx_sub_enable_workfn()` lead to silent sub-scheduler initialization failures and zombie states.

This will be addressed in a future patch.

Thanks.

--
tejun