Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * drivers/power/process.c - Functions for starting/stopping processes on | |
3 | * suspend transitions. | |
4 | * | |
5 | * Originally from swsusp. | |
6 | */ | |
7 | ||
8 | ||
9 | #undef DEBUG | |
10 | ||
11 | #include <linux/smp_lock.h> | |
12 | #include <linux/interrupt.h> | |
13 | #include <linux/suspend.h> | |
14 | #include <linux/module.h> | |
15 | ||
16 | /* | |
17 | * Timeout for stopping processes | |
18 | */ | |
19 | #define TIMEOUT (6 * HZ) | |
20 | ||
21 | ||
22 | static inline int freezeable(struct task_struct * p) | |
23 | { | |
24 | if ((p == current) || | |
25 | (p->flags & PF_NOFREEZE) || | |
26 | (p->exit_state == EXIT_ZOMBIE) || | |
27 | (p->exit_state == EXIT_DEAD) || | |
28 | (p->state == TASK_STOPPED) || | |
29 | (p->state == TASK_TRACED)) | |
30 | return 0; | |
31 | return 1; | |
32 | } | |
33 | ||
34 | /* Refrigerator is place where frozen processes are stored :-). */ | |
3e1d1d28 | 35 | void refrigerator(void) |
1da177e4 LT |
36 | { |
37 | /* Hmm, should we be allowed to suspend when there are realtime | |
38 | processes around? */ | |
39 | long save; | |
40 | save = current->state; | |
1da177e4 LT |
41 | pr_debug("%s entered refrigerator\n", current->comm); |
42 | printk("="); | |
1da177e4 | 43 | |
3e1d1d28 | 44 | frozen_process(current); |
1da177e4 LT |
45 | spin_lock_irq(¤t->sighand->siglock); |
46 | recalc_sigpending(); /* We sent fake signal, clean it up */ | |
47 | spin_unlock_irq(¤t->sighand->siglock); | |
48 | ||
2a23b5d1 PM |
49 | while (frozen(current)) { |
50 | current->state = TASK_UNINTERRUPTIBLE; | |
1da177e4 | 51 | schedule(); |
2a23b5d1 | 52 | } |
1da177e4 LT |
53 | pr_debug("%s left refrigerator\n", current->comm); |
54 | current->state = save; | |
55 | } | |
56 | ||
57 | /* 0 = success, else # of processes that we failed to stop */ | |
58 | int freeze_processes(void) | |
59 | { | |
3e1d1d28 CL |
60 | int todo; |
61 | unsigned long start_time; | |
1da177e4 | 62 | struct task_struct *g, *p; |
1322ad41 | 63 | unsigned long flags; |
3e1d1d28 | 64 | |
1da177e4 LT |
65 | printk( "Stopping tasks: " ); |
66 | start_time = jiffies; | |
67 | do { | |
68 | todo = 0; | |
69 | read_lock(&tasklist_lock); | |
70 | do_each_thread(g, p) { | |
1da177e4 LT |
71 | if (!freezeable(p)) |
72 | continue; | |
1322ad41 | 73 | if (frozen(p)) |
1da177e4 LT |
74 | continue; |
75 | ||
3e1d1d28 | 76 | freeze(p); |
1da177e4 LT |
77 | spin_lock_irqsave(&p->sighand->siglock, flags); |
78 | signal_wake_up(p, 0); | |
79 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
80 | todo++; | |
81 | } while_each_thread(g, p); | |
82 | read_unlock(&tasklist_lock); | |
83 | yield(); /* Yield is okay here */ | |
6161b2ce | 84 | if (todo && time_after(jiffies, start_time + TIMEOUT)) { |
1da177e4 LT |
85 | printk( "\n" ); |
86 | printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo ); | |
6161b2ce | 87 | break; |
1da177e4 LT |
88 | } |
89 | } while(todo); | |
3e1d1d28 | 90 | |
6161b2ce PM |
91 | /* This does not unfreeze processes that are already frozen |
92 | * (we have slightly ugly calling convention in that respect, | |
93 | * and caller must call thaw_processes() if something fails), | |
94 | * but it cleans up leftover PF_FREEZE requests. | |
95 | */ | |
96 | if (todo) { | |
97 | read_lock(&tasklist_lock); | |
98 | do_each_thread(g, p) | |
99 | if (freezing(p)) { | |
100 | pr_debug(" clean up: %s\n", p->comm); | |
101 | p->flags &= ~PF_FREEZE; | |
102 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
103 | recalc_sigpending_tsk(p); | |
104 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
105 | } | |
106 | while_each_thread(g, p); | |
107 | read_unlock(&tasklist_lock); | |
108 | return todo; | |
109 | } | |
110 | ||
1da177e4 LT |
111 | printk( "|\n" ); |
112 | BUG_ON(in_atomic()); | |
113 | return 0; | |
114 | } | |
115 | ||
116 | void thaw_processes(void) | |
117 | { | |
118 | struct task_struct *g, *p; | |
119 | ||
120 | printk( "Restarting tasks..." ); | |
121 | read_lock(&tasklist_lock); | |
122 | do_each_thread(g, p) { | |
123 | if (!freezeable(p)) | |
124 | continue; | |
3e1d1d28 | 125 | if (!thaw_process(p)) |
1da177e4 LT |
126 | printk(KERN_INFO " Strange, %s not stopped\n", p->comm ); |
127 | } while_each_thread(g, p); | |
128 | ||
129 | read_unlock(&tasklist_lock); | |
130 | schedule(); | |
131 | printk( " done\n" ); | |
132 | } | |
133 | ||
134 | EXPORT_SYMBOL(refrigerator); |