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-rw-r--r--kernel/power/process.c119
1 files changed, 3 insertions, 116 deletions
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 278946aecaf..ca634019497 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -28,121 +28,6 @@ static inline int freezeable(struct task_struct * p)
28 return 1; 28 return 1;
29} 29}
30 30
31/*
32 * freezing is complete, mark current process as frozen
33 */
34static inline void frozen_process(void)
35{
36 if (!unlikely(current->flags & PF_NOFREEZE)) {
37 current->flags |= PF_FROZEN;
38 wmb();
39 }
40 clear_freeze_flag(current);
41}
42
43/* Refrigerator is place where frozen processes are stored :-). */
44void refrigerator(void)
45{
46 /* Hmm, should we be allowed to suspend when there are realtime
47 processes around? */
48 long save;
49
50 task_lock(current);
51 if (freezing(current)) {
52 frozen_process();
53 task_unlock(current);
54 } else {
55 task_unlock(current);
56 return;
57 }
58 save = current->state;
59 pr_debug("%s entered refrigerator\n", current->comm);
60
61 spin_lock_irq(&current->sighand->siglock);
62 recalc_sigpending(); /* We sent fake signal, clean it up */
63 spin_unlock_irq(&current->sighand->siglock);
64
65 for (;;) {
66 set_current_state(TASK_UNINTERRUPTIBLE);
67 if (!frozen(current))
68 break;
69 schedule();
70 }
71 pr_debug("%s left refrigerator\n", current->comm);
72 __set_current_state(save);
73}
74
75static void fake_signal_wake_up(struct task_struct *p)
76{
77 unsigned long flags;
78
79 spin_lock_irqsave(&p->sighand->siglock, flags);
80 signal_wake_up(p, 0);
81 spin_unlock_irqrestore(&p->sighand->siglock, flags);
82}
83
84static inline bool should_send_signal(struct task_struct *p)
85{
86 return !(p->flags & PF_FREEZER_NOSIG);
87}
88
89/**
90 * freeze_task - send a freeze request to given task
91 * @p: task to send the request to
92 * @sig_only: if set, the request will only be sent if the task has the
93 * PF_FREEZER_NOSIG flag unset
94 * Return value: 'false', if @sig_only is set and the task has
95 * PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise
96 *
97 * The freeze request is sent by setting the tasks's TIF_FREEZE flag and
98 * either sending a fake signal to it or waking it up, depending on whether
99 * or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task
100 * has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its
101 * TIF_FREEZE flag will not be set.
102 */
103static bool freeze_task(struct task_struct *p, bool sig_only)
104{
105 /*
106 * We first check if the task is freezing and next if it has already
107 * been frozen to avoid the race with frozen_process() which first marks
108 * the task as frozen and next clears its TIF_FREEZE.
109 */
110 if (!freezing(p)) {
111 rmb();
112 if (frozen(p))
113 return false;
114
115 if (!sig_only || should_send_signal(p))
116 set_freeze_flag(p);
117 else
118 return false;
119 }
120
121 if (should_send_signal(p)) {
122 if (!signal_pending(p))
123 fake_signal_wake_up(p);
124 } else if (sig_only) {
125 return false;
126 } else {
127 wake_up_state(p, TASK_INTERRUPTIBLE);
128 }
129
130 return true;
131}
132
133static void cancel_freezing(struct task_struct *p)
134{
135 unsigned long flags;
136
137 if (freezing(p)) {
138 pr_debug(" clean up: %s\n", p->comm);
139 clear_freeze_flag(p);
140 spin_lock_irqsave(&p->sighand->siglock, flags);
141 recalc_sigpending_and_wake(p);
142 spin_unlock_irqrestore(&p->sighand->siglock, flags);
143 }
144}
145
146static int try_to_freeze_tasks(bool sig_only) 31static int try_to_freeze_tasks(bool sig_only)
147{ 32{
148 struct task_struct *g, *p; 33 struct task_struct *g, *p;
@@ -250,6 +135,9 @@ static void thaw_tasks(bool nosig_only)
250 if (nosig_only && should_send_signal(p)) 135 if (nosig_only && should_send_signal(p))
251 continue; 136 continue;
252 137
138 if (cgroup_frozen(p))
139 continue;
140
253 thaw_process(p); 141 thaw_process(p);
254 } while_each_thread(g, p); 142 } while_each_thread(g, p);
255 read_unlock(&tasklist_lock); 143 read_unlock(&tasklist_lock);
@@ -264,4 +152,3 @@ void thaw_processes(void)
264 printk("done.\n"); 152 printk("done.\n");
265} 153}
266 154
267EXPORT_SYMBOL(refrigerator);