Linux内核中stop_sched_class的作用是什么？

Question

stop_sched_class在内核中有什么用途？在pick_next_task函数中，调度程序将首先从stop_sched_class选择下一个任务。如果我删除内核中的这个sched_class会有什么问题吗？

#define for_each_class(class) \
   for (class = sched_class_highest; class; class = class->next)


#define sched_class_highest (&stop_sched_class)
extern const struct sched_class stop_sched_class;

/*
 * Simple, special scheduling class for the per-CPU stop tasks:
*/
const struct sched_class stop_sched_class = {
   .next                   = &rt_sched_class,

   .enqueue_task           = enqueue_task_stop,
   .dequeue_task           = dequeue_task_stop,
   .yield_task             = yield_task_stop,

   .check_preempt_curr     = check_preempt_curr_stop,

   .pick_next_task         = pick_next_task_stop,
   .put_prev_task          = put_prev_task_stop,

 #ifdef CONFIG_SMP
   .select_task_rq         = select_task_rq_stop,
 #endif

  .set_curr_task          = set_curr_task_stop,
  .task_tick              = task_tick_stop,

  .get_rr_interval        = get_rr_interval_stop,

  .prio_changed           = prio_changed_stop,
  .switched_to            = switched_to_stop,
};

- goodjesse

Answer 1

stop_sched_class用于在SMP系统上停止CPU，以实现负载平衡和CPU热插拔。该类具有最高的调度优先级。

如果您的系统未定义CONFIG_SMP，则可以尝试删除此类，但需要更改几个文件才能成功编译。

- tian_yufeng