Commit | Line | Data |
---|---|---|
029632fb PZ |
1 | #include "sched.h" |
2 | ||
fa72e9e4 IM |
3 | /* |
4 | * idle-task scheduling class. | |
5 | * | |
6 | * (NOTE: these are not related to SCHED_IDLE tasks which are | |
489a71b0 | 7 | * handled in sched/fair.c) |
fa72e9e4 IM |
8 | */ |
9 | ||
e7693a36 | 10 | #ifdef CONFIG_SMP |
0017d735 | 11 | static int |
7608dec2 | 12 | select_task_rq_idle(struct task_struct *p, int sd_flag, int flags) |
e7693a36 GH |
13 | { |
14 | return task_cpu(p); /* IDLE tasks as never migrated */ | |
15 | } | |
16 | #endif /* CONFIG_SMP */ | |
fa72e9e4 IM |
17 | /* |
18 | * Idle tasks are unconditionally rescheduled: | |
19 | */ | |
7d478721 | 20 | static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags) |
fa72e9e4 IM |
21 | { |
22 | resched_task(rq->idle); | |
23 | } | |
24 | ||
fb8d4724 | 25 | static struct task_struct *pick_next_task_idle(struct rq *rq) |
fa72e9e4 IM |
26 | { |
27 | schedstat_inc(rq, sched_goidle); | |
fa72e9e4 IM |
28 | return rq->idle; |
29 | } | |
30 | ||
31 | /* | |
32 | * It is not legal to sleep in the idle task - print a warning | |
33 | * message if some code attempts to do it: | |
34 | */ | |
35 | static void | |
371fd7e7 | 36 | dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags) |
fa72e9e4 | 37 | { |
05fa785c | 38 | raw_spin_unlock_irq(&rq->lock); |
3df0fc5b | 39 | printk(KERN_ERR "bad: scheduling from the idle thread!\n"); |
fa72e9e4 | 40 | dump_stack(); |
05fa785c | 41 | raw_spin_lock_irq(&rq->lock); |
fa72e9e4 IM |
42 | } |
43 | ||
31ee529c | 44 | static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) |
fa72e9e4 IM |
45 | { |
46 | } | |
47 | ||
8f4d37ec | 48 | static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued) |
fa72e9e4 IM |
49 | { |
50 | } | |
51 | ||
83b699ed SV |
52 | static void set_curr_task_idle(struct rq *rq) |
53 | { | |
54 | } | |
55 | ||
da7a735e | 56 | static void switched_to_idle(struct rq *rq, struct task_struct *p) |
cb469845 | 57 | { |
a8941d7e | 58 | BUG(); |
cb469845 SR |
59 | } |
60 | ||
da7a735e PZ |
61 | static void |
62 | prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 63 | { |
a8941d7e | 64 | BUG(); |
cb469845 SR |
65 | } |
66 | ||
6d686f45 | 67 | static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task) |
0d721cea PW |
68 | { |
69 | return 0; | |
70 | } | |
71 | ||
fa72e9e4 IM |
72 | /* |
73 | * Simple, special scheduling class for the per-CPU idle tasks: | |
74 | */ | |
029632fb | 75 | const struct sched_class idle_sched_class = { |
5522d5d5 | 76 | /* .next is NULL */ |
fa72e9e4 IM |
77 | /* no enqueue/yield_task for idle tasks */ |
78 | ||
79 | /* dequeue is not valid, we print a debug message there: */ | |
80 | .dequeue_task = dequeue_task_idle, | |
81 | ||
82 | .check_preempt_curr = check_preempt_curr_idle, | |
83 | ||
84 | .pick_next_task = pick_next_task_idle, | |
85 | .put_prev_task = put_prev_task_idle, | |
86 | ||
681f3e68 | 87 | #ifdef CONFIG_SMP |
4ce72a2c | 88 | .select_task_rq = select_task_rq_idle, |
681f3e68 | 89 | #endif |
fa72e9e4 | 90 | |
83b699ed | 91 | .set_curr_task = set_curr_task_idle, |
fa72e9e4 | 92 | .task_tick = task_tick_idle, |
cb469845 | 93 | |
0d721cea PW |
94 | .get_rr_interval = get_rr_interval_idle, |
95 | ||
cb469845 SR |
96 | .prio_changed = prio_changed_idle, |
97 | .switched_to = switched_to_idle, | |
fa72e9e4 | 98 | }; |