set_next_task
set_next_task(rq, p);
.set_next_task = set_next_task_dl,
.set_next_task = set_next_task_scx,
.set_next_task = set_next_task_fair,
.set_next_task = set_next_task_idle,
.set_next_task = set_next_task_rt,
void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first);
next->sched_class->set_next_task(rq, next, false);
next->sched_class->set_next_task(rq, next, true);
.set_next_task = set_next_task_stop,