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 | } | |
642dbc39 VG |
16 | |
17 | static void pre_schedule_idle(struct rq *rq, struct task_struct *prev) | |
18 | { | |
19 | idle_exit_fair(rq); | |
265f22a9 | 20 | rq_last_tick_reset(rq); |
642dbc39 VG |
21 | } |
22 | ||
23 | static void post_schedule_idle(struct rq *rq) | |
24 | { | |
25 | idle_enter_fair(rq); | |
26 | } | |
e7693a36 | 27 | #endif /* CONFIG_SMP */ |
fa72e9e4 IM |
28 | /* |
29 | * Idle tasks are unconditionally rescheduled: | |
30 | */ | |
7d478721 | 31 | static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags) |
fa72e9e4 IM |
32 | { |
33 | resched_task(rq->idle); | |
34 | } | |
35 | ||
fb8d4724 | 36 | static struct task_struct *pick_next_task_idle(struct rq *rq) |
fa72e9e4 IM |
37 | { |
38 | schedstat_inc(rq, sched_goidle); | |
642dbc39 VG |
39 | #ifdef CONFIG_SMP |
40 | /* Trigger the post schedule to do an idle_enter for CFS */ | |
41 | rq->post_schedule = 1; | |
42 | #endif | |
fa72e9e4 IM |
43 | return rq->idle; |
44 | } | |
45 | ||
46 | /* | |
47 | * It is not legal to sleep in the idle task - print a warning | |
48 | * message if some code attempts to do it: | |
49 | */ | |
50 | static void | |
371fd7e7 | 51 | dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags) |
fa72e9e4 | 52 | { |
05fa785c | 53 | raw_spin_unlock_irq(&rq->lock); |
3df0fc5b | 54 | printk(KERN_ERR "bad: scheduling from the idle thread!\n"); |
fa72e9e4 | 55 | dump_stack(); |
05fa785c | 56 | raw_spin_lock_irq(&rq->lock); |
fa72e9e4 IM |
57 | } |
58 | ||
31ee529c | 59 | static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) |
fa72e9e4 IM |
60 | { |
61 | } | |
62 | ||
8f4d37ec | 63 | static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued) |
fa72e9e4 IM |
64 | { |
65 | } | |
66 | ||
83b699ed SV |
67 | static void set_curr_task_idle(struct rq *rq) |
68 | { | |
69 | } | |
70 | ||
da7a735e | 71 | static void switched_to_idle(struct rq *rq, struct task_struct *p) |
cb469845 | 72 | { |
a8941d7e | 73 | BUG(); |
cb469845 SR |
74 | } |
75 | ||
da7a735e PZ |
76 | static void |
77 | prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 78 | { |
a8941d7e | 79 | BUG(); |
cb469845 SR |
80 | } |
81 | ||
6d686f45 | 82 | static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task) |
0d721cea PW |
83 | { |
84 | return 0; | |
85 | } | |
86 | ||
fa72e9e4 IM |
87 | /* |
88 | * Simple, special scheduling class for the per-CPU idle tasks: | |
89 | */ | |
029632fb | 90 | const struct sched_class idle_sched_class = { |
5522d5d5 | 91 | /* .next is NULL */ |
fa72e9e4 IM |
92 | /* no enqueue/yield_task for idle tasks */ |
93 | ||
94 | /* dequeue is not valid, we print a debug message there: */ | |
95 | .dequeue_task = dequeue_task_idle, | |
96 | ||
97 | .check_preempt_curr = check_preempt_curr_idle, | |
98 | ||
99 | .pick_next_task = pick_next_task_idle, | |
100 | .put_prev_task = put_prev_task_idle, | |
101 | ||
681f3e68 | 102 | #ifdef CONFIG_SMP |
4ce72a2c | 103 | .select_task_rq = select_task_rq_idle, |
642dbc39 VG |
104 | .pre_schedule = pre_schedule_idle, |
105 | .post_schedule = post_schedule_idle, | |
681f3e68 | 106 | #endif |
fa72e9e4 | 107 | |
83b699ed | 108 | .set_curr_task = set_curr_task_idle, |
fa72e9e4 | 109 | .task_tick = task_tick_idle, |
cb469845 | 110 | |
0d721cea PW |
111 | .get_rr_interval = get_rr_interval_idle, |
112 | ||
cb469845 SR |
113 | .prio_changed = prio_changed_idle, |
114 | .switched_to = switched_to_idle, | |
fa72e9e4 | 115 | }; |