/* * idle-task scheduling class. * * (NOTE: these are not related to SCHED_IDLE tasks which are * handled in sched_fair.c) */ /* * Idle tasks are unconditionally rescheduled: */ static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p) { resched_task(rq->idle); } static struct task_struct *pick_next_task_idle(struct rq *rq) { schedstat_inc(rq, sched_goidle); return rq->idle; } /* * It is not legal to sleep in the idle task - print a warning * message if some code attempts to do it: */ static void dequeue_task_idle(struct rq *rq, struct task_struct *p, int sleep) { spin_unlock_irq(&rq->lock); printk(KERN_ERR "bad: scheduling from the idle thread!\n"); dump_stack(); spin_lock_irq(&rq->lock); } static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) { } static unsigned long load_balance_idle(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_nr_move, unsigned long max_load_move, struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned, int *this_best_prio) { return 0; } static void task_tick_idle(struct rq *rq, struct task_struct *curr) { } /* * Simple, special scheduling class for the per-CPU idle tasks: */ static struct sched_class idle_sched_class __read_mostly = { /* no enqueue/yield_task for idle tasks */ /* dequeue is not valid, we print a debug message there: */ .dequeue_task = dequeue_task_idle, .check_preempt_curr = check_preempt_curr_idle, .pick_next_task = pick_next_task_idle, .put_prev_task = put_prev_task_idle, .load_balance = load_balance_idle, .task_tick = task_tick_idle, /* no .task_new for idle tasks */ };