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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; | |
41 | current->state = TASK_UNINTERRUPTIBLE; | |
42 | pr_debug("%s entered refrigerator\n", current->comm); | |
43 | printk("="); | |
1da177e4 | 44 | |
3e1d1d28 | 45 | frozen_process(current); |
1da177e4 LT |
46 | spin_lock_irq(¤t->sighand->siglock); |
47 | recalc_sigpending(); /* We sent fake signal, clean it up */ | |
48 | spin_unlock_irq(¤t->sighand->siglock); | |
49 | ||
3e1d1d28 | 50 | while (frozen(current)) |
1da177e4 LT |
51 | schedule(); |
52 | pr_debug("%s left refrigerator\n", current->comm); | |
53 | current->state = save; | |
54 | } | |
55 | ||
56 | /* 0 = success, else # of processes that we failed to stop */ | |
57 | int freeze_processes(void) | |
58 | { | |
3e1d1d28 CL |
59 | int todo; |
60 | unsigned long start_time; | |
1da177e4 | 61 | struct task_struct *g, *p; |
3e1d1d28 | 62 | |
1da177e4 LT |
63 | printk( "Stopping tasks: " ); |
64 | start_time = jiffies; | |
65 | do { | |
66 | todo = 0; | |
67 | read_lock(&tasklist_lock); | |
68 | do_each_thread(g, p) { | |
69 | unsigned long flags; | |
70 | if (!freezeable(p)) | |
71 | continue; | |
3e1d1d28 | 72 | if ((frozen(p)) || |
1da177e4 LT |
73 | (p->state == TASK_TRACED) || |
74 | (p->state == TASK_STOPPED)) | |
75 | continue; | |
76 | ||
3e1d1d28 | 77 | freeze(p); |
1da177e4 LT |
78 | spin_lock_irqsave(&p->sighand->siglock, flags); |
79 | signal_wake_up(p, 0); | |
80 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
81 | todo++; | |
82 | } while_each_thread(g, p); | |
83 | read_unlock(&tasklist_lock); | |
84 | yield(); /* Yield is okay here */ | |
85 | if (time_after(jiffies, start_time + TIMEOUT)) { | |
86 | printk( "\n" ); | |
87 | printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo ); | |
88 | return todo; | |
89 | } | |
90 | } while(todo); | |
3e1d1d28 | 91 | |
1da177e4 LT |
92 | printk( "|\n" ); |
93 | BUG_ON(in_atomic()); | |
94 | return 0; | |
95 | } | |
96 | ||
97 | void thaw_processes(void) | |
98 | { | |
99 | struct task_struct *g, *p; | |
100 | ||
101 | printk( "Restarting tasks..." ); | |
102 | read_lock(&tasklist_lock); | |
103 | do_each_thread(g, p) { | |
104 | if (!freezeable(p)) | |
105 | continue; | |
3e1d1d28 | 106 | if (!thaw_process(p)) |
1da177e4 LT |
107 | printk(KERN_INFO " Strange, %s not stopped\n", p->comm ); |
108 | } while_each_thread(g, p); | |
109 | ||
110 | read_unlock(&tasklist_lock); | |
111 | schedule(); | |
112 | printk( " done\n" ); | |
113 | } | |
114 | ||
115 | EXPORT_SYMBOL(refrigerator); |