Commit | Line | Data |
---|---|---|
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) { |
14b5b7cf | 94 | printk("\n"); |
dbeeec5f | 95 | printk(KERN_ERR "Freezing of tasks %s after %d.%02d seconds " |
a0a1a5fd | 96 | "(%d tasks refusing to freeze, wq_busy=%d):\n", |
dbeeec5f | 97 | wakeup ? "aborted" : "failed", |
a0a1a5fd TH |
98 | elapsed_csecs / 100, elapsed_csecs % 100, |
99 | todo - wq_busy, wq_busy); | |
100 | ||
6161b2ce | 101 | read_lock(&tasklist_lock); |
02aaeb9b | 102 | do_each_thread(g, p) { |
6907483b | 103 | if (!wakeup && !freezer_should_skip(p) && |
a3201227 | 104 | p != current && freezing(p) && !frozen(p)) |
4f598458 | 105 | sched_show_task(p); |
02aaeb9b | 106 | } while_each_thread(g, p); |
6161b2ce | 107 | read_unlock(&tasklist_lock); |
438e2ce6 RW |
108 | } else { |
109 | printk("(elapsed %d.%02d seconds) ", elapsed_csecs / 100, | |
110 | elapsed_csecs % 100); | |
6161b2ce PM |
111 | } |
112 | ||
e7cd8a72 | 113 | return todo ? -EBUSY : 0; |
11b2ce2b RW |
114 | } |
115 | ||
116 | /** | |
2aede851 | 117 | * freeze_processes - Signal user space processes to enter the refrigerator. |
03afed8b TH |
118 | * |
119 | * On success, returns 0. On failure, -errno and system is fully thawed. | |
11b2ce2b RW |
120 | */ |
121 | int freeze_processes(void) | |
122 | { | |
e7cd8a72 | 123 | int error; |
11b2ce2b | 124 | |
a3201227 TH |
125 | if (!pm_freezing) |
126 | atomic_inc(&system_freezing_cnt); | |
127 | ||
b842ee57 | 128 | printk("Freezing user space processes ... "); |
a3201227 | 129 | pm_freezing = true; |
ebb12db5 | 130 | error = try_to_freeze_tasks(true); |
2aede851 RW |
131 | if (!error) { |
132 | printk("done."); | |
133 | oom_killer_disable(); | |
134 | } | |
135 | printk("\n"); | |
136 | BUG_ON(in_atomic()); | |
137 | ||
03afed8b TH |
138 | if (error) |
139 | thaw_processes(); | |
2aede851 RW |
140 | return error; |
141 | } | |
142 | ||
143 | /** | |
144 | * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator. | |
03afed8b TH |
145 | * |
146 | * On success, returns 0. On failure, -errno and system is fully thawed. | |
2aede851 RW |
147 | */ |
148 | int freeze_kernel_threads(void) | |
149 | { | |
150 | int error; | |
11b2ce2b | 151 | |
b842ee57 | 152 | printk("Freezing remaining freezable tasks ... "); |
a3201227 | 153 | pm_nosig_freezing = true; |
ebb12db5 | 154 | error = try_to_freeze_tasks(false); |
2aede851 RW |
155 | if (!error) |
156 | printk("done."); | |
7f33d49a | 157 | |
b842ee57 | 158 | printk("\n"); |
2aede851 | 159 | BUG_ON(in_atomic()); |
7f33d49a | 160 | |
03afed8b TH |
161 | if (error) |
162 | thaw_processes(); | |
b842ee57 | 163 | return error; |
1da177e4 LT |
164 | } |
165 | ||
6cd8dedc | 166 | void thaw_processes(void) |
1da177e4 LT |
167 | { |
168 | struct task_struct *g, *p; | |
169 | ||
a3201227 TH |
170 | if (pm_freezing) |
171 | atomic_dec(&system_freezing_cnt); | |
172 | pm_freezing = false; | |
173 | pm_nosig_freezing = false; | |
174 | ||
6cd8dedc TH |
175 | oom_killer_enable(); |
176 | ||
177 | printk("Restarting tasks ... "); | |
178 | ||
179 | thaw_workqueues(); | |
180 | ||
1da177e4 | 181 | read_lock(&tasklist_lock); |
a9b6f562 | 182 | do_each_thread(g, p) { |
a5be2d0d | 183 | __thaw_task(p); |
a9b6f562 | 184 | } while_each_thread(g, p); |
1da177e4 | 185 | read_unlock(&tasklist_lock); |
7f33d49a | 186 | |
1da177e4 | 187 | schedule(); |
14b5b7cf | 188 | printk("done.\n"); |
1da177e4 LT |
189 | } |
190 |