Hi Changwoo, On Sat, Mar 15, 2025 at 10:35:03AM +0900, Changwoo Min wrote: > Hi Andrea, ... > > +/** > > + * scx_bpf_select_cpu_and - Pick an idle CPU usable by task @p, > > + * prioritizing those in @cpus_allowed > > + * @p: task_struct to select a CPU for > > + * @prev_cpu: CPU @p was on previously > > + * @wake_flags: %SCX_WAKE_* flags > > + * @cpus_allowed: cpumask of allowed CPUs > > + * @flags: %SCX_PICK_IDLE* flags > > + * > > + * Can only be called from ops.select_cpu() if the built-in CPU selection is > > + * enabled - ops.update_idle() is missing or %SCX_OPS_KEEP_BUILTIN_IDLE is set. > > + * @p, @prev_cpu and @wake_flags match ops.select_cpu(). > > I think that scx_bpf_select_cpu_and () needs to be allowed to > call from ops.enqueue(). That is because many scx schedulers have > some logic similar to scx_bpf_select_cpu_dfl() to kick an idle > CPU proactively. That's a valid point, it can be a good opportunity to consolidate the logic used in most schedulers, where the same "pick idle CPU" function is called from both ops.select_cpu() and ops.enqueue() and have a unified core API usable from both contexts. I'll extend the scope of this kfunc to include ops.enqueue() in the next version and run some tests with it. Thanks! -Andrea
