On Fri, Aug 28, 2020 at 03:51:10PM -0400, Julien Desfossez wrote:
> +/*
> + * If runqueue has only one task which used up its slice and if the sibling
> + * is forced idle, then trigger schedule to give forced idle task a chance.
> + */
> +static void resched_forceidle_sibling(struct rq *rq, struct sched_entity *se)
> +{
> + int cpu = cpu_of(rq), sibling_cpu;
> +
> + if (rq->cfs.nr_running > 1 || !__entity_slice_used(se))
> + return;
> +
> + for_each_cpu(sibling_cpu, cpu_smt_mask(cpu)) {
> + struct rq *sibling_rq;
> + if (sibling_cpu == cpu)
> + continue;
> + if (cpu_is_offline(sibling_cpu))
> + continue;
> +
> + sibling_rq = cpu_rq(sibling_cpu);
> + if (sibling_rq->core_forceidle) {
> + resched_curr(sibling_rq);
> + }
> + }
The only pupose of this loop seem to be to find if we have a forceidle;
surely we can avoid that by storing this during the pick.
> +}
static void task_tick_core(struct rq *rq)
{
if (sched_core_enabled(rq))
resched_forceidle_sibling(rq, &rq->curr->se);
}
#else
static void task_tick_core(struct rq *rq) { }
> +#endif
> +
> /*
> * scheduler tick hitting a task of our scheduling class.
> *
> @@ -10654,6 +10688,11 @@ static void task_tick_fair(struct rq *rq, struct
> task_struct *curr, int queued)
>
> update_misfit_status(curr, rq);
> update_overutilized_status(task_rq(curr));
> +
> +#ifdef CONFIG_SCHED_CORE
> + if (sched_core_enabled(rq))
> + resched_forceidle_sibling(rq, &curr->se);
> +#endif
Then you can ditch the #ifdef here
> }
>
> /*
> --
> 2.17.1
>
