fa72e9e484
add kernel/sched_idletask.c - which implements the idle thread scheduling class. This further simplifies sched.c (under CFS), for example a number of 'if (p == rq->idle)' type of special-cases can be removed from sched.c, and schedule() gets simpler too. Signed-off-by: Ingo Molnar <mingo@elte.hu>
72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
/*
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* idle-task scheduling class.
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*
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* (NOTE: these are not related to SCHED_IDLE tasks which are
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* handled in sched_fair.c)
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*/
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/*
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* Idle tasks are unconditionally rescheduled:
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*/
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static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p)
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{
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resched_task(rq->idle);
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}
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static struct task_struct *pick_next_task_idle(struct rq *rq, u64 now)
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{
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schedstat_inc(rq, sched_goidle);
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return rq->idle;
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}
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/*
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* It is not legal to sleep in the idle task - print a warning
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* message if some code attempts to do it:
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*/
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static void
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dequeue_task_idle(struct rq *rq, struct task_struct *p, int sleep, u64 now)
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{
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spin_unlock_irq(&rq->lock);
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printk(KERN_ERR "bad: scheduling from the idle thread!\n");
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dump_stack();
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spin_lock_irq(&rq->lock);
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}
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static void put_prev_task_idle(struct rq *rq, struct task_struct *prev, u64 now)
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{
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}
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static int
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load_balance_idle(struct rq *this_rq, int this_cpu, struct rq *busiest,
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unsigned long max_nr_move, unsigned long max_load_move,
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struct sched_domain *sd, enum cpu_idle_type idle,
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int *all_pinned, unsigned long *total_load_moved)
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{
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return 0;
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}
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static void task_tick_idle(struct rq *rq, struct task_struct *curr)
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{
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}
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/*
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* Simple, special scheduling class for the per-CPU idle tasks:
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*/
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static struct sched_class idle_sched_class __read_mostly = {
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/* no enqueue/yield_task for idle tasks */
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/* dequeue is not valid, we print a debug message there: */
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.dequeue_task = dequeue_task_idle,
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.check_preempt_curr = check_preempt_curr_idle,
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.pick_next_task = pick_next_task_idle,
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.put_prev_task = put_prev_task_idle,
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.load_balance = load_balance_idle,
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.task_tick = task_tick_idle,
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/* no .task_new for idle tasks */
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};
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