]>
Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
029632fb PZ |
2 | #include "sched.h" |
3 | ||
fa72e9e4 IM |
4 | /* |
5 | * idle-task scheduling class. | |
6 | * | |
7 | * (NOTE: these are not related to SCHED_IDLE tasks which are | |
489a71b0 | 8 | * handled in sched/fair.c) |
fa72e9e4 IM |
9 | */ |
10 | ||
e7693a36 | 11 | #ifdef CONFIG_SMP |
0017d735 | 12 | static int |
ac66f547 | 13 | select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags) |
e7693a36 GH |
14 | { |
15 | return task_cpu(p); /* IDLE tasks as never migrated */ | |
16 | } | |
97fb7a0a | 17 | #endif |
38033c37 | 18 | |
fa72e9e4 IM |
19 | /* |
20 | * Idle tasks are unconditionally rescheduled: | |
21 | */ | |
7d478721 | 22 | static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags) |
fa72e9e4 | 23 | { |
8875125e | 24 | resched_curr(rq); |
fa72e9e4 IM |
25 | } |
26 | ||
606dba2e | 27 | static struct task_struct * |
d8ac8971 | 28 | pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) |
fa72e9e4 | 29 | { |
3f1d2a31 | 30 | put_prev_task(rq, prev); |
10e2f1ac | 31 | update_idle_core(rq); |
ae92882e | 32 | schedstat_inc(rq->sched_goidle); |
97fb7a0a | 33 | |
fa72e9e4 IM |
34 | return rq->idle; |
35 | } | |
36 | ||
37 | /* | |
38 | * It is not legal to sleep in the idle task - print a warning | |
39 | * message if some code attempts to do it: | |
40 | */ | |
41 | static void | |
371fd7e7 | 42 | dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags) |
fa72e9e4 | 43 | { |
05fa785c | 44 | raw_spin_unlock_irq(&rq->lock); |
3df0fc5b | 45 | printk(KERN_ERR "bad: scheduling from the idle thread!\n"); |
fa72e9e4 | 46 | dump_stack(); |
05fa785c | 47 | raw_spin_lock_irq(&rq->lock); |
fa72e9e4 IM |
48 | } |
49 | ||
31ee529c | 50 | static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) |
fa72e9e4 IM |
51 | { |
52 | } | |
53 | ||
d84b3131 FW |
54 | /* |
55 | * scheduler tick hitting a task of our scheduling class. | |
56 | * | |
57 | * NOTE: This function can be called remotely by the tick offload that | |
58 | * goes along full dynticks. Therefore no local assumption can be made | |
59 | * and everything must be accessed through the @rq and @curr passed in | |
60 | * parameters. | |
61 | */ | |
8f4d37ec | 62 | static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued) |
fa72e9e4 IM |
63 | { |
64 | } | |
65 | ||
83b699ed SV |
66 | static void set_curr_task_idle(struct rq *rq) |
67 | { | |
68 | } | |
69 | ||
da7a735e | 70 | static void switched_to_idle(struct rq *rq, struct task_struct *p) |
cb469845 | 71 | { |
a8941d7e | 72 | BUG(); |
cb469845 SR |
73 | } |
74 | ||
da7a735e PZ |
75 | static void |
76 | prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio) | |
cb469845 | 77 | { |
a8941d7e | 78 | BUG(); |
cb469845 SR |
79 | } |
80 | ||
6d686f45 | 81 | static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task) |
0d721cea PW |
82 | { |
83 | return 0; | |
84 | } | |
85 | ||
90e362f4 TG |
86 | static void update_curr_idle(struct rq *rq) |
87 | { | |
88 | } | |
89 | ||
fa72e9e4 IM |
90 | /* |
91 | * Simple, special scheduling class for the per-CPU idle tasks: | |
92 | */ | |
029632fb | 93 | const struct sched_class idle_sched_class = { |
5522d5d5 | 94 | /* .next is NULL */ |
fa72e9e4 IM |
95 | /* no enqueue/yield_task for idle tasks */ |
96 | ||
97 | /* dequeue is not valid, we print a debug message there: */ | |
98 | .dequeue_task = dequeue_task_idle, | |
99 | ||
100 | .check_preempt_curr = check_preempt_curr_idle, | |
101 | ||
102 | .pick_next_task = pick_next_task_idle, | |
103 | .put_prev_task = put_prev_task_idle, | |
104 | ||
681f3e68 | 105 | #ifdef CONFIG_SMP |
4ce72a2c | 106 | .select_task_rq = select_task_rq_idle, |
c5b28038 | 107 | .set_cpus_allowed = set_cpus_allowed_common, |
681f3e68 | 108 | #endif |
fa72e9e4 | 109 | |
83b699ed | 110 | .set_curr_task = set_curr_task_idle, |
fa72e9e4 | 111 | .task_tick = task_tick_idle, |
cb469845 | 112 | |
0d721cea PW |
113 | .get_rr_interval = get_rr_interval_idle, |
114 | ||
cb469845 SR |
115 | .prio_changed = prio_changed_idle, |
116 | .switched_to = switched_to_idle, | |
90e362f4 | 117 | .update_curr = update_curr_idle, |
fa72e9e4 | 118 | }; |