122 lines
2.8 KiB
C
122 lines
2.8 KiB
C
|
/*
|
||
|
|
* drivers/power/process.c - Functions for starting/stopping processes on
|
||
|
|
* suspend transitions.
|
||
|
|
*
|
||
|
|
* Originally from swsusp.
|
||
|
|
*/
|
||
|
|
|
||
|
|
|
||
|
|
#undef DEBUG
|
||
|
|
|
||
|
|
#include <linux/smp_lock.h>
|
||
|
|
#include <linux/interrupt.h>
|
||
|
|
#include <linux/suspend.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Timeout for stopping processes
|
||
|
|
*/
|
||
|
|
#define TIMEOUT (6 * HZ)
|
||
|
|
|
||
|
|
|
||
|
|
static inline int freezeable(struct task_struct * p)
|
||
|
|
{
|
||
|
|
if ((p == current) ||
|
||
|
|
(p->flags & PF_NOFREEZE) ||
|
||
|
|
(p->exit_state == EXIT_ZOMBIE) ||
|
||
|
|
(p->exit_state == EXIT_DEAD) ||
|
||
|
|
(p->state == TASK_STOPPED) ||
|
||
|
|
(p->state == TASK_TRACED))
|
||
|
|
return 0;
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Refrigerator is place where frozen processes are stored :-). */
|
||
|
|
void refrigerator(unsigned long flag)
|
||
|
|
{
|
||
|
|
/* Hmm, should we be allowed to suspend when there are realtime
|
||
|
|
processes around? */
|
||
|
|
long save;
|
||
|
|
save = current->state;
|
||
|
|
current->state = TASK_UNINTERRUPTIBLE;
|
||
|
|
pr_debug("%s entered refrigerator\n", current->comm);
|
||
|
|
printk("=");
|
||
|
|
current->flags &= ~PF_FREEZE;
|
||
|
|
|
||
|
|
spin_lock_irq(¤t->sighand->siglock);
|
||
|
|
recalc_sigpending(); /* We sent fake signal, clean it up */
|
||
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
||
|
|
|
||
|
|
current->flags |= PF_FROZEN;
|
||
|
|
while (current->flags & PF_FROZEN)
|
||
|
|
schedule();
|
||
|
|
pr_debug("%s left refrigerator\n", current->comm);
|
||
|
|
current->state = save;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* 0 = success, else # of processes that we failed to stop */
|
||
|
|
int freeze_processes(void)
|
||
|
|
{
|
||
|
|
int todo;
|
||
|
|
unsigned long start_time;
|
||
|
|
struct task_struct *g, *p;
|
||
|
|
|
||
|
|
printk( "Stopping tasks: " );
|
||
|
|
start_time = jiffies;
|
||
|
|
do {
|
||
|
|
todo = 0;
|
||
|
|
read_lock(&tasklist_lock);
|
||
|
|
do_each_thread(g, p) {
|
||
|
|
unsigned long flags;
|
||
|
|
if (!freezeable(p))
|
||
|
|
continue;
|
||
|
|
if ((p->flags & PF_FROZEN) ||
|
||
|
|
(p->state == TASK_TRACED) ||
|
||
|
|
(p->state == TASK_STOPPED))
|
||
|
|
continue;
|
||
|
|
|
||
|
|
/* FIXME: smp problem here: we may not access other process' flags
|
||
|
|
without locking */
|
||
|
|
p->flags |= PF_FREEZE;
|
||
|
|
spin_lock_irqsave(&p->sighand->siglock, flags);
|
||
|
|
signal_wake_up(p, 0);
|
||
|
|
spin_unlock_irqrestore(&p->sighand->siglock, flags);
|
||
|
|
todo++;
|
||
|
|
} while_each_thread(g, p);
|
||
|
|
read_unlock(&tasklist_lock);
|
||
|
|
yield(); /* Yield is okay here */
|
||
|
|
if (time_after(jiffies, start_time + TIMEOUT)) {
|
||
|
|
printk( "\n" );
|
||
|
|
printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo );
|
||
|
|
return todo;
|
||
|
|
}
|
||
|
|
} while(todo);
|
||
|
|
|
||
|
|
printk( "|\n" );
|
||
|
|
BUG_ON(in_atomic());
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
void thaw_processes(void)
|
||
|
|
{
|
||
|
|
struct task_struct *g, *p;
|
||
|
|
|
||
|
|
printk( "Restarting tasks..." );
|
||
|
|
read_lock(&tasklist_lock);
|
||
|
|
do_each_thread(g, p) {
|
||
|
|
if (!freezeable(p))
|
||
|
|
continue;
|
||
|
|
if (p->flags & PF_FROZEN) {
|
||
|
|
p->flags &= ~PF_FROZEN;
|
||
|
|
wake_up_process(p);
|
||
|
|
} else
|
||
|
|
printk(KERN_INFO " Strange, %s not stopped\n", p->comm );
|
||
|
|
} while_each_thread(g, p);
|
||
|
|
|
||
|
|
read_unlock(&tasklist_lock);
|
||
|
|
schedule();
|
||
|
|
printk( " done\n" );
|
||
|
|
}
|
||
|
|
|
||
|
|
EXPORT_SYMBOL(refrigerator);
|