[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / sched / stop_task.c

#include "sched.h"

/*
 * stop-task scheduling class.
 *
 * The stop task is the highest priority task in the system, it preempts
 * everything and will be preempted by nothing.
 *
 * See kernel/stop_machine.c
 */

#ifdef CONFIG_SMP
static int
select_task_rq_stop(struct task_struct *p, int sd_flag, int flags)
{
	return task_cpu(p); /* stop tasks as never migrate */
}
#endif /* CONFIG_SMP */

static void
check_preempt_curr_stop(struct rq *rq, struct task_struct *p, int flags)
{
	/* we're never preempted */
}

static struct task_struct *pick_next_task_stop(struct rq *rq)
{
	struct task_struct *stop = rq->stop;

	if (stop && stop->on_rq) {
		stop->se.exec_start = rq->clock_task;
		return stop;
	}

	return NULL;
}

static void
enqueue_task_stop(struct rq *rq, struct task_struct *p, int flags)
{
	inc_nr_running(rq);
}

static void
dequeue_task_stop(struct rq *rq, struct task_struct *p, int flags)
{
	dec_nr_running(rq);
}

static void yield_task_stop(struct rq *rq)
{
	BUG(); /* the stop task should never yield, its pointless. */
}

static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
{
	struct task_struct *curr = rq->curr;
	u64 delta_exec;

	delta_exec = rq->clock_task - curr->se.exec_start;
	if (unlikely((s64)delta_exec < 0))
		delta_exec = 0;

	schedstat_set(curr->se.statistics.exec_max,
			max(curr->se.statistics.exec_max, delta_exec));

	curr->se.sum_exec_runtime += delta_exec;
	account_group_exec_runtime(curr, delta_exec);

	curr->se.exec_start = rq->clock_task;
	cpuacct_charge(curr, delta_exec);
}

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

static void set_curr_task_stop(struct rq *rq)
{
	struct task_struct *stop = rq->stop;

	stop->se.exec_start = rq->clock_task;
}

static void switched_to_stop(struct rq *rq, struct task_struct *p)
{
	BUG(); /* its impossible to change to this class */
}

static void
prio_changed_stop(struct rq *rq, struct task_struct *p, int oldprio)
{
	BUG(); /* how!?, what priority? */
}

static unsigned int
get_rr_interval_stop(struct rq *rq, struct task_struct *task)
{
	return 0;
}

/*
 * 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,
};
Commit	Line	Data
029632fb PZ	1	#include "sched.h"
029632fb PZ	2
34f971f6 PZ	3	/*
	4	* stop-task scheduling class.
	5	*
	6	* The stop task is the highest priority task in the system, it preempts
	7	* everything and will be preempted by nothing.
	8	*
	9	* See kernel/stop_machine.c
	10	*/
	11
	12	#ifdef CONFIG_SMP
	13	static int
7608dec2	14	select_task_rq_stop(struct task_struct *p, int sd_flag, int flags)
34f971f6 PZ	15	{
	16	return task_cpu(p); /* stop tasks as never migrate */
	17	}
	18	#endif /* CONFIG_SMP */
	19
	20	static void
	21	check_preempt_curr_stop(struct rq rq, struct task_struct p, int flags)
	22	{
1e5a7405	23	/* we're never preempted */
34f971f6 PZ	24	}
	25
	26	static struct task_struct pick_next_task_stop(struct rq rq)
	27	{
	28	struct task_struct *stop = rq->stop;
	29
8f618968 MG	30	if (stop && stop->on_rq) {
8f618968 MG	31	stop->se.exec_start = rq->clock_task;
34f971f6	32	return stop;
8f618968	33	}
34f971f6 PZ	34
	35	return NULL;
	36	}
	37
	38	static void
	39	enqueue_task_stop(struct rq rq, struct task_struct p, int flags)
	40	{
953bfcd1	41	inc_nr_running(rq);
34f971f6 PZ	42	}
	43
	44	static void
	45	dequeue_task_stop(struct rq rq, struct task_struct p, int flags)
	46	{
953bfcd1	47	dec_nr_running(rq);
34f971f6 PZ	48	}
	49
	50	static void yield_task_stop(struct rq *rq)
	51	{
	52	BUG(); /* the stop task should never yield, its pointless. */
	53	}
	54
	55	static void put_prev_task_stop(struct rq rq, struct task_struct prev)
	56	{
8f618968 MG	57	struct task_struct *curr = rq->curr;
	58	u64 delta_exec;
	59
	60	delta_exec = rq->clock_task - curr->se.exec_start;
	61	if (unlikely((s64)delta_exec < 0))
	62	delta_exec = 0;
	63
	64	schedstat_set(curr->se.statistics.exec_max,
	65	max(curr->se.statistics.exec_max, delta_exec));
	66
	67	curr->se.sum_exec_runtime += delta_exec;
	68	account_group_exec_runtime(curr, delta_exec);
	69
	70	curr->se.exec_start = rq->clock_task;
	71	cpuacct_charge(curr, delta_exec);
34f971f6 PZ	72	}
	73
	74	static void task_tick_stop(struct rq rq, struct task_struct curr, int queued)
	75	{
	76	}
	77
	78	static void set_curr_task_stop(struct rq *rq)
	79	{
8f618968 MG	80	struct task_struct *stop = rq->stop;
	81
	82	stop->se.exec_start = rq->clock_task;
34f971f6 PZ	83	}
34f971f6 PZ	84
da7a735e	85	static void switched_to_stop(struct rq rq, struct task_struct p)
34f971f6 PZ	86	{
	87	BUG(); /* its impossible to change to this class */
	88	}
	89
da7a735e PZ	90	static void
da7a735e PZ	91	prio_changed_stop(struct rq rq, struct task_struct p, int oldprio)
34f971f6 PZ	92	{
	93	BUG(); /* how!?, what priority? */
	94	}
	95
	96	static unsigned int
	97	get_rr_interval_stop(struct rq rq, struct task_struct task)
	98	{
	99	return 0;
	100	}
	101
	102	/*
	103	* Simple, special scheduling class for the per-CPU stop tasks:
	104	*/
029632fb	105	const struct sched_class stop_sched_class = {
34f971f6 PZ	106	.next = &rt_sched_class,
	107
	108	.enqueue_task = enqueue_task_stop,
	109	.dequeue_task = dequeue_task_stop,
	110	.yield_task = yield_task_stop,
	111
	112	.check_preempt_curr = check_preempt_curr_stop,
	113
	114	.pick_next_task = pick_next_task_stop,
	115	.put_prev_task = put_prev_task_stop,
	116
	117	#ifdef CONFIG_SMP
	118	.select_task_rq = select_task_rq_stop,
	119	#endif
	120
	121	.set_curr_task = set_curr_task_stop,
	122	.task_tick = task_tick_stop,
	123
	124	.get_rr_interval = get_rr_interval_stop,
	125
	126	.prio_changed = prio_changed_stop,
	127	.switched_to = switched_to_stop,
34f971f6	128	};