2 * drivers/power/process.c - Functions for starting/stopping processes on
5 * Originally from swsusp.
11 #include <linux/smp_lock.h>
12 #include <linux/interrupt.h>
13 #include <linux/suspend.h>
14 #include <linux/module.h>
17 * Timeout for stopping processes
19 #define TIMEOUT (6 * HZ)
22 static inline int freezeable(struct task_struct * p)
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))
34 /* Refrigerator is place where frozen processes are stored :-). */
35 void refrigerator(void)
37 /* Hmm, should we be allowed to suspend when there are realtime
40 save = current->state;
41 current->state = TASK_UNINTERRUPTIBLE;
42 pr_debug("%s entered refrigerator\n", current->comm);
45 frozen_process(current);
46 spin_lock_irq(¤t->sighand->siglock);
47 recalc_sigpending(); /* We sent fake signal, clean it up */
48 spin_unlock_irq(¤t->sighand->siglock);
50 while (frozen(current))
52 pr_debug("%s left refrigerator\n", current->comm);
53 current->state = save;
56 /* 0 = success, else # of processes that we failed to stop */
57 int freeze_processes(void)
60 unsigned long start_time;
61 struct task_struct *g, *p;
63 printk( "Stopping tasks: " );
67 read_lock(&tasklist_lock);
68 do_each_thread(g, p) {
73 (p->state == TASK_TRACED) ||
74 (p->state == TASK_STOPPED))
78 spin_lock_irqsave(&p->sighand->siglock, flags);
80 spin_unlock_irqrestore(&p->sighand->siglock, flags);
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)) {
87 printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo );
97 void thaw_processes(void)
99 struct task_struct *g, *p;
101 printk( "Restarting tasks..." );
102 read_lock(&tasklist_lock);
103 do_each_thread(g, p) {
106 if (!thaw_process(p))
107 printk(KERN_INFO " Strange, %s not stopped\n", p->comm );
108 } while_each_thread(g, p);
110 read_unlock(&tasklist_lock);
115 EXPORT_SYMBOL(refrigerator);