Re: [RFC PATCH 07/13] sched: Add core wide task selection and scheduling.

Peter Zijlstra
2020-04-17T11:18:42Z

On Thu, Apr 16, 2020 at 11:39:05AM +0800, Chen Yu wrote:

> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 02495d44870f..ef101a3ef583 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -4477,9 +4477,14 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
> return next;
> }
>
> - prev->sched_class->put_prev_task(rq, prev);
> - if (!rq->nr_running)
> - newidle_balance(rq, rf);
> +
> +#ifdef CONFIG_SMP
> + for_class_range(class, prev->sched_class, &idle_sched_class) {
> + if (class->balance(rq, prev, rf))
> + break;
> + }
> +#endif
> + put_prev_task(rq, prev);
>
> smt_mask = cpu_smt_mask(cpu);

Instead of duplicating that, how about you put the existing copy in a
function to share? finish_prev_task() perhaps?

Also, can you please make newidle_balance() static again; I forgot doing
that in 6e2df0581f56, which would've made you notice this sooner I
suppose.