X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fpower%2Fprocess.c;h=b2a5f671d6cd3f2d164e44ad20ad7780a7e00377;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=78d92dc6a1edc8119ae616bf184e83ae26ec27e8;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/kernel/power/process.c b/kernel/power/process.c
index 78d92dc6a..b2a5f671d 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -12,11 +12,12 @@
 #include <linux/interrupt.h>
 #include <linux/suspend.h>
 #include <linux/module.h>
+#include <linux/syscalls.h>
 
 /* 
  * Timeout for stopping processes
  */
-#define TIMEOUT	(6 * HZ)
+#define TIMEOUT	(20 * HZ)
 
 
 static inline int freezeable(struct task_struct * p)
@@ -25,73 +26,118 @@ static inline int freezeable(struct task_struct * p)
 	    (p->flags & PF_NOFREEZE) ||
 	    (p->exit_state == EXIT_ZOMBIE) ||
 	    (p->exit_state == EXIT_DEAD) ||
-	    (p->state == TASK_STOPPED) ||
-	    (p->state == TASK_TRACED))
+	    (p->state == TASK_STOPPED))
 		return 0;
 	return 1;
 }
 
 /* Refrigerator is place where frozen processes are stored :-). */
-void refrigerator(unsigned long flag)
+void refrigerator(void)
 {
 	/* 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;
 
+	frozen_process(current);
 	spin_lock_irq(&current->sighand->siglock);
 	recalc_sigpending(); /* We sent fake signal, clean it up */
 	spin_unlock_irq(&current->sighand->siglock);
 
-	current->flags |= PF_FROZEN;
-	while (current->flags & PF_FROZEN)
+	while (frozen(current)) {
+		current->state = TASK_UNINTERRUPTIBLE;
 		schedule();
+	}
 	pr_debug("%s left refrigerator\n", current->comm);
 	current->state = save;
 }
 
+static inline void freeze_process(struct task_struct *p)
+{
+	unsigned long flags;
+
+	if (!freezing(p)) {
+		freeze(p);
+		spin_lock_irqsave(&p->sighand->siglock, flags);
+		signal_wake_up(p, 0);
+		spin_unlock_irqrestore(&p->sighand->siglock, flags);
+	}
+}
+
 /* 0 = success, else # of processes that we failed to stop */
 int freeze_processes(void)
 {
-       int todo;
-       unsigned long start_time;
+	int todo, nr_user, user_frozen;
+	unsigned long start_time;
 	struct task_struct *g, *p;
-	
+	unsigned long flags;
+
 	printk( "Stopping tasks: " );
 	start_time = jiffies;
+	user_frozen = 0;
 	do {
-		todo = 0;
+		nr_user = 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))
+			if (frozen(p))
 				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++;
+			if (p->mm && !(p->flags & PF_BORROWED_MM)) {
+				/* The task is a user-space one.
+				 * Freeze it unless there's a vfork completion
+				 * pending
+				 */
+				if (!p->vfork_done)
+					freeze_process(p);
+				nr_user++;
+			} else {
+				/* Freeze only if the user space is frozen */
+				if (user_frozen)
+					freeze_process(p);
+				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;
+		todo += nr_user;
+		if (!user_frozen && !nr_user) {
+			sys_sync();
+			start_time = jiffies;
 		}
+		user_frozen = !nr_user;
+		yield();			/* Yield is okay here */
+		if (todo && time_after(jiffies, start_time + TIMEOUT))
+			break;
 	} while(todo);
-	
+
+	/* This does not unfreeze processes that are already frozen
+	 * (we have slightly ugly calling convention in that respect,
+	 * and caller must call thaw_processes() if something fails),
+	 * but it cleans up leftover PF_FREEZE requests.
+	 */
+	if (todo) {
+		printk( "\n" );
+		printk(KERN_ERR " stopping tasks timed out "
+			"after %d seconds (%d tasks remaining):\n",
+			TIMEOUT / HZ, todo);
+		read_lock(&tasklist_lock);
+		do_each_thread(g, p) {
+			if (freezeable(p) && !frozen(p))
+				printk(KERN_ERR "  %s\n", p->comm);
+			if (freezing(p)) {
+				pr_debug("  clean up: %s\n", p->comm);
+				p->flags &= ~PF_FREEZE;
+				spin_lock_irqsave(&p->sighand->siglock, flags);
+				recalc_sigpending_tsk(p);
+				spin_unlock_irqrestore(&p->sighand->siglock, flags);
+			}
+		} while_each_thread(g, p);
+		read_unlock(&tasklist_lock);
+		return todo;
+	}
+
 	printk( "|\n" );
 	BUG_ON(in_atomic());
 	return 0;
@@ -106,10 +152,7 @@ void thaw_processes(void)
 	do_each_thread(g, p) {
 		if (!freezeable(p))
 			continue;
-		if (p->flags & PF_FROZEN) {
-			p->flags &= ~PF_FROZEN;
-			wake_up_process(p);
-		} else
+		if (!thaw_process(p))
 			printk(KERN_INFO " Strange, %s not stopped\n", p->comm );
 	} while_each_thread(g, p);