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 |
ac66f547 | 12 | select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags) |
e7693a36 GH |
13 | { |
14 | return task_cpu(p); /* IDLE tasks as never migrated */ | |
15 | } | |
16 | #endif /* CONFIG_SMP */ | |
38033c37 | 17 | |
fa72e9e4 IM |
18 | /* |
19 | * Idle tasks are unconditionally rescheduled: | |
20 | */ | |
7d478721 | 21 | static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags) |
fa72e9e4 | 22 | { |
8875125e | 23 | resched_curr(rq); |
fa72e9e4 IM |
24 | } |
25 | ||
606dba2e PZ |
26 | static struct task_struct * |
27 | pick_next_task_idle(struct rq *rq, struct task_struct *prev) | |
fa72e9e4 | 28 | { |
3f1d2a31 | 29 | put_prev_task(rq, prev); |
606dba2e | 30 | |
fa72e9e4 | 31 | schedstat_inc(rq, sched_goidle); |
fa72e9e4 IM |
32 | return rq->idle; |
33 | } | |
34 | ||
35 | /* | |
36 | * It is not legal to sleep in the idle task - print a warning | |
37 | * message if some code attempts to do it: | |
38 | */ | |
39 | static void | |
371fd7e7 | 40 | dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags) |
fa72e9e4 | 41 | { |
05fa785c | 42 | raw_spin_unlock_irq(&rq->lock); |
3df0fc5b | 43 | printk(KERN_ERR "bad: scheduling from the idle thread!\n"); |
fa72e9e4 | 44 | dump_stack(); |
05fa785c | 45 | raw_spin_lock_irq(&rq->lock); |
fa72e9e4 IM |
46 | } |
47 | ||
31ee529c | 48 | static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) |
fa72e9e4 | 49 | { |
38033c37 PZ |
50 | idle_exit_fair(rq); |
51 | rq_last_tick_reset(rq); | |
fa72e9e4 IM |
52 | } |
53 | ||
8f4d37ec | 54 | static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued) |
fa72e9e4 IM |
55 | { |
56 | } | |
57 | ||
83b699ed SV |
58 | static void set_curr_task_idle(struct rq *rq) |
59 | { | |
60 | } | |
61 | ||
da7a735e | 62 | static void switched_to_idle(struct rq *rq, struct task_struct *p) |
cb469845 | 63 | { |
a8941d7e | 64 | BUG(); |
cb469845 SR |
65 | } |
66 | ||
da7a735e PZ |
67 | static void |
68 | prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 69 | { |
a8941d7e | 70 | BUG(); |
cb469845 SR |
71 | } |
72 | ||
6d686f45 | 73 | static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task) |
0d721cea PW |
74 | { |
75 | return 0; | |
76 | } | |
77 | ||
90e362f4 TG |
78 | static void update_curr_idle(struct rq *rq) |
79 | { | |
80 | } | |
81 | ||
fa72e9e4 IM |
82 | /* |
83 | * Simple, special scheduling class for the per-CPU idle tasks: | |
84 | */ | |
029632fb | 85 | const struct sched_class idle_sched_class = { |
5522d5d5 | 86 | /* .next is NULL */ |
fa72e9e4 IM |
87 | /* no enqueue/yield_task for idle tasks */ |
88 | ||
89 | /* dequeue is not valid, we print a debug message there: */ | |
90 | .dequeue_task = dequeue_task_idle, | |
91 | ||
92 | .check_preempt_curr = check_preempt_curr_idle, | |
93 | ||
94 | .pick_next_task = pick_next_task_idle, | |
95 | .put_prev_task = put_prev_task_idle, | |
96 | ||
681f3e68 | 97 | #ifdef CONFIG_SMP |
4ce72a2c | 98 | .select_task_rq = select_task_rq_idle, |
681f3e68 | 99 | #endif |
fa72e9e4 | 100 | |
83b699ed | 101 | .set_curr_task = set_curr_task_idle, |
fa72e9e4 | 102 | .task_tick = task_tick_idle, |
cb469845 | 103 | |
0d721cea PW |
104 | .get_rr_interval = get_rr_interval_idle, |
105 | ||
cb469845 SR |
106 | .prio_changed = prio_changed_idle, |
107 | .switched_to = switched_to_idle, | |
90e362f4 | 108 | .update_curr = update_curr_idle, |
fa72e9e4 | 109 | }; |