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6161b2ce81
If process freezing fails, some processes are frozen, and rest are left in "were asked to be frozen" state. Thats wrong, we should leave it in some consistent state. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
134 lines
3.1 KiB
C
134 lines
3.1 KiB
C
/*
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* drivers/power/process.c - Functions for starting/stopping processes on
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* suspend transitions.
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*
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* Originally from swsusp.
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*/
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#undef DEBUG
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#include <linux/smp_lock.h>
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#include <linux/interrupt.h>
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#include <linux/suspend.h>
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#include <linux/module.h>
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/*
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* Timeout for stopping processes
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*/
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#define TIMEOUT (6 * HZ)
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static inline int freezeable(struct task_struct * p)
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{
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if ((p == current) ||
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(p->flags & PF_NOFREEZE) ||
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(p->exit_state == EXIT_ZOMBIE) ||
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(p->exit_state == EXIT_DEAD) ||
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(p->state == TASK_STOPPED) ||
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(p->state == TASK_TRACED))
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return 0;
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return 1;
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}
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/* Refrigerator is place where frozen processes are stored :-). */
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void refrigerator(void)
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{
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/* Hmm, should we be allowed to suspend when there are realtime
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processes around? */
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long save;
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save = current->state;
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pr_debug("%s entered refrigerator\n", current->comm);
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printk("=");
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frozen_process(current);
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spin_lock_irq(¤t->sighand->siglock);
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recalc_sigpending(); /* We sent fake signal, clean it up */
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spin_unlock_irq(¤t->sighand->siglock);
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while (frozen(current)) {
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current->state = TASK_UNINTERRUPTIBLE;
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schedule();
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}
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pr_debug("%s left refrigerator\n", current->comm);
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current->state = save;
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}
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/* 0 = success, else # of processes that we failed to stop */
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int freeze_processes(void)
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{
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int todo;
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unsigned long start_time;
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struct task_struct *g, *p;
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unsigned long flags;
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printk( "Stopping tasks: " );
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start_time = jiffies;
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do {
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todo = 0;
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read_lock(&tasklist_lock);
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do_each_thread(g, p) {
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if (!freezeable(p))
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continue;
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if (frozen(p))
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continue;
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freeze(p);
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spin_lock_irqsave(&p->sighand->siglock, flags);
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signal_wake_up(p, 0);
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spin_unlock_irqrestore(&p->sighand->siglock, flags);
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todo++;
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} while_each_thread(g, p);
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read_unlock(&tasklist_lock);
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yield(); /* Yield is okay here */
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if (todo && time_after(jiffies, start_time + TIMEOUT)) {
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printk( "\n" );
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printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo );
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break;
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}
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} while(todo);
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/* This does not unfreeze processes that are already frozen
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* (we have slightly ugly calling convention in that respect,
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* and caller must call thaw_processes() if something fails),
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* but it cleans up leftover PF_FREEZE requests.
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*/
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if (todo) {
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read_lock(&tasklist_lock);
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do_each_thread(g, p)
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if (freezing(p)) {
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pr_debug(" clean up: %s\n", p->comm);
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p->flags &= ~PF_FREEZE;
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spin_lock_irqsave(&p->sighand->siglock, flags);
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recalc_sigpending_tsk(p);
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spin_unlock_irqrestore(&p->sighand->siglock, flags);
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}
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while_each_thread(g, p);
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read_unlock(&tasklist_lock);
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return todo;
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}
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printk( "|\n" );
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BUG_ON(in_atomic());
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return 0;
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}
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void thaw_processes(void)
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{
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struct task_struct *g, *p;
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printk( "Restarting tasks..." );
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read_lock(&tasklist_lock);
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do_each_thread(g, p) {
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if (!freezeable(p))
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continue;
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if (!thaw_process(p))
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printk(KERN_INFO " Strange, %s not stopped\n", p->comm );
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} while_each_thread(g, p);
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read_unlock(&tasklist_lock);
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schedule();
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printk( " done\n" );
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}
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EXPORT_SYMBOL(refrigerator);
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