Eric Lee / smarc-fsl-linux-kernel

Blame view

kernel/sched/stop_task.c 2.15 KB
edit raw normal view history
029632fbb   Peter Zijlstra   sched: Make separ... 
1
 
  #include "sched.h"
34f971f6f   Peter Zijlstra   sched: Create spe... 
2
3
4
5
6
7
8
9
10
11
12
 
  /*
   * stop-task scheduling class.
   *
   * The stop task is the highest priority task in the system, it preempts
   * everything and will be preempted by nothing.
   *
   * See kernel/stop_machine.c
   */
  
  #ifdef CONFIG_SMP
  static int
7608dec2c   Peter Zijlstra   sched: Drop the r... 
13
 
  select_task_rq_stop(struct task_struct *p, int sd_flag, int flags)
34f971f6f   Peter Zijlstra   sched: Create spe... 
14
15
16
17
18
19
20
21
 
  {
  	return task_cpu(p); /* stop tasks as never migrate */
  }
  #endif /* CONFIG_SMP */
  
  static void
  check_preempt_curr_stop(struct rq *rq, struct task_struct *p, int flags)
  {
1e5a74059   Peter Zijlstra   sched: Fix cross-... 
22
 
  	/* we're never preempted */
34f971f6f   Peter Zijlstra   sched: Create spe... 
23
24
25
26
27
 
  }
  
  static struct task_struct *pick_next_task_stop(struct rq *rq)
  {
  	struct task_struct *stop = rq->stop;
fd2f4419b   Peter Zijlstra   sched: Provide p-... 
28
 
  	if (stop && stop->on_rq)
34f971f6f   Peter Zijlstra   sched: Create spe... 
29
30
31
32
33
34
35
36
 
  		return stop;
  
  	return NULL;
  }
  
  static void
  enqueue_task_stop(struct rq *rq, struct task_struct *p, int flags)
  {
953bfcd10   Paul Turner   sched: Implement ... 
37
 
  	inc_nr_running(rq);
34f971f6f   Peter Zijlstra   sched: Create spe... 
38
39
40
41
42
 
  }
  
  static void
  dequeue_task_stop(struct rq *rq, struct task_struct *p, int flags)
  {
953bfcd10   Paul Turner   sched: Implement ... 
43
 
  	dec_nr_running(rq);
34f971f6f   Peter Zijlstra   sched: Create spe... 
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
 
  }
  
  static void yield_task_stop(struct rq *rq)
  {
  	BUG(); /* the stop task should never yield, its pointless. */
  }
  
  static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
  {
  }
  
  static void task_tick_stop(struct rq *rq, struct task_struct *curr, int queued)
  {
  }
  
  static void set_curr_task_stop(struct rq *rq)
  {
  }
da7a735e5   Peter Zijlstra   sched: Fix switch... 
62
 
  static void switched_to_stop(struct rq *rq, struct task_struct *p)
34f971f6f   Peter Zijlstra   sched: Create spe... 
63
64
65
 
  {
  	BUG(); /* its impossible to change to this class */
  }
da7a735e5   Peter Zijlstra   sched: Fix switch... 
66
67
 
  static void
  prio_changed_stop(struct rq *rq, struct task_struct *p, int oldprio)
34f971f6f   Peter Zijlstra   sched: Create spe... 
68
69
70
71
72
73
74
75
76
77
78
79
80
 
  {
  	BUG(); /* how!?, what priority? */
  }
  
  static unsigned int
  get_rr_interval_stop(struct rq *rq, struct task_struct *task)
  {
  	return 0;
  }
  
  /*
   * Simple, special scheduling class for the per-CPU stop tasks:
   */
029632fbb   Peter Zijlstra   sched: Make separ... 
81
 
  const struct sched_class stop_sched_class = {
34f971f6f   Peter Zijlstra   sched: Create spe... 
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
 
  	.next			= &rt_sched_class,
  
  	.enqueue_task		= enqueue_task_stop,
  	.dequeue_task		= dequeue_task_stop,
  	.yield_task		= yield_task_stop,
  
  	.check_preempt_curr	= check_preempt_curr_stop,
  
  	.pick_next_task		= pick_next_task_stop,
  	.put_prev_task		= put_prev_task_stop,
  
  #ifdef CONFIG_SMP
  	.select_task_rq		= select_task_rq_stop,
  #endif
  
  	.set_curr_task          = set_curr_task_stop,
  	.task_tick		= task_tick_stop,
  
  	.get_rr_interval	= get_rr_interval_stop,
  
  	.prio_changed		= prio_changed_stop,
  	.switched_to		= switched_to_stop,
34f971f6f   Peter Zijlstra   sched: Create spe... 
104
 
  };