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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> | |
02aaeb9b | 15 | #include <linux/syscalls.h> |
7dfb7103 | 16 | #include <linux/freezer.h> |
1da177e4 LT |
17 | |
18 | /* | |
19 | * Timeout for stopping processes | |
20 | */ | |
02aaeb9b | 21 | #define TIMEOUT (20 * HZ) |
1da177e4 LT |
22 | |
23 | ||
24 | static inline int freezeable(struct task_struct * p) | |
25 | { | |
26 | if ((p == current) || | |
27 | (p->flags & PF_NOFREEZE) || | |
28 | (p->exit_state == EXIT_ZOMBIE) || | |
29 | (p->exit_state == EXIT_DEAD) || | |
85b6bce3 | 30 | (p->state == TASK_STOPPED)) |
1da177e4 LT |
31 | return 0; |
32 | return 1; | |
33 | } | |
34 | ||
35 | /* Refrigerator is place where frozen processes are stored :-). */ | |
3e1d1d28 | 36 | void refrigerator(void) |
1da177e4 LT |
37 | { |
38 | /* Hmm, should we be allowed to suspend when there are realtime | |
39 | processes around? */ | |
40 | long save; | |
41 | save = current->state; | |
1da177e4 LT |
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 | ||
2a23b5d1 PM |
50 | while (frozen(current)) { |
51 | current->state = TASK_UNINTERRUPTIBLE; | |
1da177e4 | 52 | schedule(); |
2a23b5d1 | 53 | } |
1da177e4 LT |
54 | pr_debug("%s left refrigerator\n", current->comm); |
55 | current->state = save; | |
56 | } | |
57 | ||
02aaeb9b RW |
58 | static inline void freeze_process(struct task_struct *p) |
59 | { | |
60 | unsigned long flags; | |
61 | ||
62 | if (!freezing(p)) { | |
63 | freeze(p); | |
64 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
65 | signal_wake_up(p, 0); | |
66 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
67 | } | |
68 | } | |
69 | ||
a7ef7878 RW |
70 | static void cancel_freezing(struct task_struct *p) |
71 | { | |
72 | unsigned long flags; | |
73 | ||
74 | if (freezing(p)) { | |
75 | pr_debug(" clean up: %s\n", p->comm); | |
76 | do_not_freeze(p); | |
77 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
78 | recalc_sigpending_tsk(p); | |
79 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
80 | } | |
81 | } | |
82 | ||
1da177e4 LT |
83 | /* 0 = success, else # of processes that we failed to stop */ |
84 | int freeze_processes(void) | |
85 | { | |
02aaeb9b | 86 | int todo, nr_user, user_frozen; |
3e1d1d28 | 87 | unsigned long start_time; |
1da177e4 | 88 | struct task_struct *g, *p; |
3e1d1d28 | 89 | |
1da177e4 LT |
90 | printk( "Stopping tasks: " ); |
91 | start_time = jiffies; | |
02aaeb9b | 92 | user_frozen = 0; |
1da177e4 | 93 | do { |
02aaeb9b | 94 | nr_user = todo = 0; |
1da177e4 LT |
95 | read_lock(&tasklist_lock); |
96 | do_each_thread(g, p) { | |
1da177e4 LT |
97 | if (!freezeable(p)) |
98 | continue; | |
1322ad41 | 99 | if (frozen(p)) |
1da177e4 | 100 | continue; |
a7ef7878 RW |
101 | if (p->state == TASK_TRACED && frozen(p->parent)) { |
102 | cancel_freezing(p); | |
103 | continue; | |
104 | } | |
02aaeb9b RW |
105 | if (p->mm && !(p->flags & PF_BORROWED_MM)) { |
106 | /* The task is a user-space one. | |
107 | * Freeze it unless there's a vfork completion | |
108 | * pending | |
109 | */ | |
110 | if (!p->vfork_done) | |
111 | freeze_process(p); | |
112 | nr_user++; | |
113 | } else { | |
114 | /* Freeze only if the user space is frozen */ | |
115 | if (user_frozen) | |
116 | freeze_process(p); | |
117 | todo++; | |
118 | } | |
1da177e4 LT |
119 | } while_each_thread(g, p); |
120 | read_unlock(&tasklist_lock); | |
02aaeb9b RW |
121 | todo += nr_user; |
122 | if (!user_frozen && !nr_user) { | |
123 | sys_sync(); | |
124 | start_time = jiffies; | |
125 | } | |
126 | user_frozen = !nr_user; | |
1da177e4 | 127 | yield(); /* Yield is okay here */ |
02aaeb9b | 128 | if (todo && time_after(jiffies, start_time + TIMEOUT)) |
6161b2ce | 129 | break; |
1da177e4 | 130 | } while(todo); |
3e1d1d28 | 131 | |
6161b2ce PM |
132 | /* This does not unfreeze processes that are already frozen |
133 | * (we have slightly ugly calling convention in that respect, | |
134 | * and caller must call thaw_processes() if something fails), | |
135 | * but it cleans up leftover PF_FREEZE requests. | |
136 | */ | |
137 | if (todo) { | |
02aaeb9b RW |
138 | printk( "\n" ); |
139 | printk(KERN_ERR " stopping tasks timed out " | |
140 | "after %d seconds (%d tasks remaining):\n", | |
141 | TIMEOUT / HZ, todo); | |
6161b2ce | 142 | read_lock(&tasklist_lock); |
02aaeb9b RW |
143 | do_each_thread(g, p) { |
144 | if (freezeable(p) && !frozen(p)) | |
145 | printk(KERN_ERR " %s\n", p->comm); | |
a7ef7878 | 146 | cancel_freezing(p); |
02aaeb9b | 147 | } while_each_thread(g, p); |
6161b2ce PM |
148 | read_unlock(&tasklist_lock); |
149 | return todo; | |
150 | } | |
151 | ||
1da177e4 LT |
152 | printk( "|\n" ); |
153 | BUG_ON(in_atomic()); | |
154 | return 0; | |
155 | } | |
156 | ||
157 | void thaw_processes(void) | |
158 | { | |
159 | struct task_struct *g, *p; | |
160 | ||
161 | printk( "Restarting tasks..." ); | |
162 | read_lock(&tasklist_lock); | |
163 | do_each_thread(g, p) { | |
164 | if (!freezeable(p)) | |
165 | continue; | |
3e1d1d28 | 166 | if (!thaw_process(p)) |
1da177e4 LT |
167 | printk(KERN_INFO " Strange, %s not stopped\n", p->comm ); |
168 | } while_each_thread(g, p); | |
169 | ||
170 | read_unlock(&tasklist_lock); | |
171 | schedule(); | |
172 | printk( " done\n" ); | |
173 | } | |
174 | ||
175 | EXPORT_SYMBOL(refrigerator); |