[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / sched_idletask.c

/*
 * idle-task scheduling class.
 *
 * (NOTE: these are not related to SCHED_IDLE tasks which are
 *  handled in sched_fair.c)
 */

#ifdef CONFIG_SMP
static int select_task_rq_idle(struct task_struct *p, int sync)
{
	return task_cpu(p); /* IDLE tasks as never migrated */
}
#endif /* CONFIG_SMP */
/*
 * 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)
{
}

#ifdef CONFIG_SMP
static unsigned long
load_balance_idle(struct rq *this_rq, int this_cpu, struct rq *busiest,
		  unsigned long max_load_move,
		  struct sched_domain *sd, enum cpu_idle_type idle,
		  int *all_pinned, int *this_best_prio)
{
	return 0;
}

static int
move_one_task_idle(struct rq *this_rq, int this_cpu, struct rq *busiest,
		   struct sched_domain *sd, enum cpu_idle_type idle)
{
	return 0;
}
#endif

static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
{
}

static void set_curr_task_idle(struct rq *rq)
{
}

static void switched_to_idle(struct rq *rq, struct task_struct *p,
			     int running)
{
	/* Can this actually happen?? */
	if (running)
		resched_task(rq->curr);
	else
		check_preempt_curr(rq, p);
}

static void prio_changed_idle(struct rq *rq, struct task_struct *p,
			      int oldprio, int running)
{
	/* This can happen for hot plug CPUS */

	/*
	 * Reschedule if we are currently running on this runqueue and
	 * our priority decreased, or if we are not currently running on
	 * this runqueue and our priority is higher than the current's
	 */
	if (running) {
		if (p->prio > oldprio)
			resched_task(rq->curr);
	} else
		check_preempt_curr(rq, p);
}

/*
 * Simple, special scheduling class for the per-CPU idle tasks:
 */
static const struct sched_class idle_sched_class = {
	/* .next is NULL */
	/* no enqueue/yield_task for idle tasks */

	/* dequeue is not valid, we print a debug message there: */
	.dequeue_task		= dequeue_task_idle,
#ifdef CONFIG_SMP
	.select_task_rq		= select_task_rq_idle,
#endif /* CONFIG_SMP */

	.check_preempt_curr	= check_preempt_curr_idle,

	.pick_next_task		= pick_next_task_idle,
	.put_prev_task		= put_prev_task_idle,

#ifdef CONFIG_SMP
	.load_balance		= load_balance_idle,
	.move_one_task		= move_one_task_idle,
#endif

	.set_curr_task          = set_curr_task_idle,
	.task_tick		= task_tick_idle,

	.prio_changed		= prio_changed_idle,
	.switched_to		= switched_to_idle,

	/* no .task_new for idle tasks */
};
Commit	Line	Data
fa72e9e4 IM	1	/*
	2	* idle-task scheduling class.
	3	*
	4	* (NOTE: these are not related to SCHED_IDLE tasks which are
	5	* handled in sched_fair.c)
	6	*/
	7
e7693a36 GH	8	#ifdef CONFIG_SMP
	9	static int select_task_rq_idle(struct task_struct *p, int sync)
	10	{
	11	return task_cpu(p); /* IDLE tasks as never migrated */
	12	}
	13	#endif /* CONFIG_SMP */
fa72e9e4 IM	14	/*
	15	* Idle tasks are unconditionally rescheduled:
	16	*/
	17	static void check_preempt_curr_idle(struct rq rq, struct task_struct p)
	18	{
	19	resched_task(rq->idle);
	20	}
	21
fb8d4724	22	static struct task_struct pick_next_task_idle(struct rq rq)
fa72e9e4 IM	23	{
	24	schedstat_inc(rq, sched_goidle);
	25
	26	return rq->idle;
	27	}
	28
	29	/*
	30	* It is not legal to sleep in the idle task - print a warning
	31	* message if some code attempts to do it:
	32	*/
	33	static void
f02231e5	34	dequeue_task_idle(struct rq rq, struct task_struct p, int sleep)
fa72e9e4 IM	35	{
	36	spin_unlock_irq(&rq->lock);
	37	printk(KERN_ERR "bad: scheduling from the idle thread!\n");
	38	dump_stack();
	39	spin_lock_irq(&rq->lock);
	40	}
	41
31ee529c	42	static void put_prev_task_idle(struct rq rq, struct task_struct prev)
fa72e9e4 IM	43	{
	44	}
	45
681f3e68	46	#ifdef CONFIG_SMP
43010659	47	static unsigned long
fa72e9e4	48	load_balance_idle(struct rq this_rq, int this_cpu, struct rq busiest,
e1d1484f PW	49	unsigned long max_load_move,
	50	struct sched_domain *sd, enum cpu_idle_type idle,
	51	int all_pinned, int this_best_prio)
	52	{
	53	return 0;
	54	}
	55
	56	static int
	57	move_one_task_idle(struct rq this_rq, int this_cpu, struct rq busiest,
	58	struct sched_domain *sd, enum cpu_idle_type idle)
fa72e9e4 IM	59	{
	60	return 0;
	61	}
681f3e68	62	#endif
fa72e9e4	63
8f4d37ec	64	static void task_tick_idle(struct rq rq, struct task_struct curr, int queued)
fa72e9e4 IM	65	{
	66	}
	67
83b699ed SV	68	static void set_curr_task_idle(struct rq *rq)
	69	{
	70	}
	71
cb469845 SR	72	static void switched_to_idle(struct rq rq, struct task_struct p,
	73	int running)
	74	{
	75	/* Can this actually happen?? */
	76	if (running)
	77	resched_task(rq->curr);
	78	else
	79	check_preempt_curr(rq, p);
	80	}
	81
	82	static void prio_changed_idle(struct rq rq, struct task_struct p,
	83	int oldprio, int running)
	84	{
	85	/* This can happen for hot plug CPUS */
	86
	87	/*
	88	* Reschedule if we are currently running on this runqueue and
	89	* our priority decreased, or if we are not currently running on
	90	* this runqueue and our priority is higher than the current's
	91	*/
	92	if (running) {
	93	if (p->prio > oldprio)
	94	resched_task(rq->curr);
	95	} else
	96	check_preempt_curr(rq, p);
	97	}
	98
fa72e9e4 IM	99	/*
	100	* Simple, special scheduling class for the per-CPU idle tasks:
	101	*/
2abdad0a	102	static const struct sched_class idle_sched_class = {
5522d5d5	103	/* .next is NULL */
fa72e9e4 IM	104	/* no enqueue/yield_task for idle tasks */
	105
	106	/* dequeue is not valid, we print a debug message there: */
	107	.dequeue_task = dequeue_task_idle,
e7693a36 GH	108	#ifdef CONFIG_SMP
	109	.select_task_rq = select_task_rq_idle,
	110	#endif /* CONFIG_SMP */
fa72e9e4 IM	111
	112	.check_preempt_curr = check_preempt_curr_idle,
	113
	114	.pick_next_task = pick_next_task_idle,
	115	.put_prev_task = put_prev_task_idle,
	116
681f3e68	117	#ifdef CONFIG_SMP
fa72e9e4	118	.load_balance = load_balance_idle,
e1d1484f	119	.move_one_task = move_one_task_idle,
681f3e68	120	#endif
fa72e9e4	121
83b699ed	122	.set_curr_task = set_curr_task_idle,
fa72e9e4	123	.task_tick = task_tick_idle,
cb469845 SR	124
	125	.prio_changed = prio_changed_idle,
	126	.switched_to = switched_to_idle,
	127
fa72e9e4 IM	128	/* no .task_new for idle tasks */
fa72e9e4 IM	129	};