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 pr_debug("%s entered refrigerator\n", current->comm);
44 frozen_process(current);
45 spin_lock_irq(¤t->sighand->siglock);
46 recalc_sigpending(); /* We sent fake signal, clean it up */
47 spin_unlock_irq(¤t->sighand->siglock);
49 while (frozen(current)) {
50 current->state = TASK_UNINTERRUPTIBLE;
53 pr_debug("%s left refrigerator\n", current->comm);
54 current->state = save;
57 /* 0 = success, else # of processes that we failed to stop */
58 int freeze_processes(void)
61 unsigned long start_time;
62 struct task_struct *g, *p;
65 printk( "Stopping tasks: " );
69 read_lock(&tasklist_lock);
70 do_each_thread(g, p) {
77 spin_lock_irqsave(&p->sighand->siglock, flags);
79 spin_unlock_irqrestore(&p->sighand->siglock, flags);
81 } while_each_thread(g, p);
82 read_unlock(&tasklist_lock);
83 yield(); /* Yield is okay here */
84 if (time_after(jiffies, start_time + TIMEOUT)) {
86 printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo );
96 void thaw_processes(void)
98 struct task_struct *g, *p;
100 printk( "Restarting tasks..." );
101 read_lock(&tasklist_lock);
102 do_each_thread(g, p) {
105 if (!thaw_process(p))
106 printk(KERN_INFO " Strange, %s not stopped\n", p->comm );
107 } while_each_thread(g, p);
109 read_unlock(&tasklist_lock);
114 EXPORT_SYMBOL(refrigerator);