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 | ||
1da177e4 | 11 | #include <linux/interrupt.h> |
1a8670a2 | 12 | #include <linux/oom.h> |
1da177e4 LT |
13 | #include <linux/suspend.h> |
14 | #include <linux/module.h> | |
02aaeb9b | 15 | #include <linux/syscalls.h> |
7dfb7103 | 16 | #include <linux/freezer.h> |
be404f02 | 17 | #include <linux/delay.h> |
a0a1a5fd | 18 | #include <linux/workqueue.h> |
1da177e4 LT |
19 | |
20 | /* | |
21 | * Timeout for stopping processes | |
22 | */ | |
02aaeb9b | 23 | #define TIMEOUT (20 * HZ) |
1da177e4 | 24 | |
ebb12db5 | 25 | static int try_to_freeze_tasks(bool sig_only) |
1da177e4 | 26 | { |
1da177e4 | 27 | struct task_struct *g, *p; |
11b2ce2b RW |
28 | unsigned long end_time; |
29 | unsigned int todo; | |
a0a1a5fd | 30 | bool wq_busy = false; |
438e2ce6 | 31 | struct timeval start, end; |
f0af566d | 32 | u64 elapsed_csecs64; |
438e2ce6 | 33 | unsigned int elapsed_csecs; |
dbeeec5f | 34 | bool wakeup = false; |
438e2ce6 RW |
35 | |
36 | do_gettimeofday(&start); | |
3e1d1d28 | 37 | |
11b2ce2b | 38 | end_time = jiffies + TIMEOUT; |
a0a1a5fd TH |
39 | |
40 | if (!sig_only) | |
41 | freeze_workqueues_begin(); | |
42 | ||
be404f02 | 43 | while (true) { |
11b2ce2b | 44 | todo = 0; |
1da177e4 LT |
45 | read_lock(&tasklist_lock); |
46 | do_each_thread(g, p) { | |
85f1d476 | 47 | if (p == current || !freeze_task(p, sig_only)) |
d5d8c597 RW |
48 | continue; |
49 | ||
13b1c3d4 RM |
50 | /* |
51 | * Now that we've done set_freeze_flag, don't | |
52 | * perturb a task in TASK_STOPPED or TASK_TRACED. | |
53 | * It is "frozen enough". If the task does wake | |
54 | * up, it will immediately call try_to_freeze. | |
8cfe400c TH |
55 | * |
56 | * Because freeze_task() goes through p's | |
57 | * scheduler lock after setting TIF_FREEZE, it's | |
58 | * guaranteed that either we see TASK_RUNNING or | |
59 | * try_to_stop() after schedule() in ptrace/signal | |
60 | * stop sees TIF_FREEZE. | |
13b1c3d4 RM |
61 | */ |
62 | if (!task_is_stopped_or_traced(p) && | |
63 | !freezer_should_skip(p)) | |
ba96a0c8 | 64 | todo++; |
1da177e4 LT |
65 | } while_each_thread(g, p); |
66 | read_unlock(&tasklist_lock); | |
a0a1a5fd TH |
67 | |
68 | if (!sig_only) { | |
69 | wq_busy = freeze_workqueues_busy(); | |
70 | todo += wq_busy; | |
71 | } | |
72 | ||
be404f02 | 73 | if (!todo || time_after(jiffies, end_time)) |
6161b2ce | 74 | break; |
be404f02 | 75 | |
a2867e08 | 76 | if (pm_wakeup_pending()) { |
dbeeec5f RW |
77 | wakeup = true; |
78 | break; | |
79 | } | |
80 | ||
be404f02 TH |
81 | /* |
82 | * We need to retry, but first give the freezing tasks some | |
83 | * time to enter the regrigerator. | |
84 | */ | |
85 | msleep(10); | |
86 | } | |
3e1d1d28 | 87 | |
438e2ce6 RW |
88 | do_gettimeofday(&end); |
89 | elapsed_csecs64 = timeval_to_ns(&end) - timeval_to_ns(&start); | |
90 | do_div(elapsed_csecs64, NSEC_PER_SEC / 100); | |
91 | elapsed_csecs = elapsed_csecs64; | |
92 | ||
6161b2ce | 93 | if (todo) { |
11b2ce2b RW |
94 | /* This does not unfreeze processes that are already frozen |
95 | * (we have slightly ugly calling convention in that respect, | |
96 | * and caller must call thaw_processes() if something fails), | |
97 | * but it cleans up leftover PF_FREEZE requests. | |
98 | */ | |
14b5b7cf | 99 | printk("\n"); |
dbeeec5f | 100 | printk(KERN_ERR "Freezing of tasks %s after %d.%02d seconds " |
a0a1a5fd | 101 | "(%d tasks refusing to freeze, wq_busy=%d):\n", |
dbeeec5f | 102 | wakeup ? "aborted" : "failed", |
a0a1a5fd TH |
103 | elapsed_csecs / 100, elapsed_csecs % 100, |
104 | todo - wq_busy, wq_busy); | |
105 | ||
106 | thaw_workqueues(); | |
107 | ||
6161b2ce | 108 | read_lock(&tasklist_lock); |
02aaeb9b | 109 | do_each_thread(g, p) { |
6907483b TH |
110 | if (!wakeup && !freezer_should_skip(p) && |
111 | freezing(p) && !frozen(p)) | |
4f598458 | 112 | sched_show_task(p); |
a7ef7878 | 113 | cancel_freezing(p); |
02aaeb9b | 114 | } while_each_thread(g, p); |
6161b2ce | 115 | read_unlock(&tasklist_lock); |
438e2ce6 RW |
116 | } else { |
117 | printk("(elapsed %d.%02d seconds) ", elapsed_csecs / 100, | |
118 | elapsed_csecs % 100); | |
6161b2ce PM |
119 | } |
120 | ||
e7cd8a72 | 121 | return todo ? -EBUSY : 0; |
11b2ce2b RW |
122 | } |
123 | ||
124 | /** | |
2aede851 | 125 | * freeze_processes - Signal user space processes to enter the refrigerator. |
11b2ce2b RW |
126 | */ |
127 | int freeze_processes(void) | |
128 | { | |
e7cd8a72 | 129 | int error; |
11b2ce2b | 130 | |
b842ee57 | 131 | printk("Freezing user space processes ... "); |
ebb12db5 | 132 | error = try_to_freeze_tasks(true); |
2aede851 RW |
133 | if (!error) { |
134 | printk("done."); | |
135 | oom_killer_disable(); | |
136 | } | |
137 | printk("\n"); | |
138 | BUG_ON(in_atomic()); | |
139 | ||
140 | return error; | |
141 | } | |
142 | ||
143 | /** | |
144 | * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator. | |
145 | */ | |
146 | int freeze_kernel_threads(void) | |
147 | { | |
148 | int error; | |
11b2ce2b | 149 | |
b842ee57 | 150 | printk("Freezing remaining freezable tasks ... "); |
ebb12db5 | 151 | error = try_to_freeze_tasks(false); |
2aede851 RW |
152 | if (!error) |
153 | printk("done."); | |
7f33d49a | 154 | |
b842ee57 | 155 | printk("\n"); |
2aede851 | 156 | BUG_ON(in_atomic()); |
7f33d49a | 157 | |
b842ee57 | 158 | return error; |
1da177e4 LT |
159 | } |
160 | ||
6cd8dedc | 161 | void thaw_processes(void) |
1da177e4 LT |
162 | { |
163 | struct task_struct *g, *p; | |
164 | ||
6cd8dedc TH |
165 | oom_killer_enable(); |
166 | ||
167 | printk("Restarting tasks ... "); | |
168 | ||
169 | thaw_workqueues(); | |
170 | ||
1da177e4 | 171 | read_lock(&tasklist_lock); |
a9b6f562 | 172 | do_each_thread(g, p) { |
5a7aadfe | 173 | if (cgroup_freezing_or_frozen(p)) |
5a06915c MH |
174 | continue; |
175 | ||
a5be2d0d | 176 | __thaw_task(p); |
a9b6f562 | 177 | } while_each_thread(g, p); |
1da177e4 | 178 | read_unlock(&tasklist_lock); |
7f33d49a | 179 | |
1da177e4 | 180 | schedule(); |
14b5b7cf | 181 | printk("done.\n"); |
1da177e4 LT |
182 | } |
183 |