[PATCH 0/3] Freezer cleanups

[PATCH 0/3] Freezer cleanups

[Rafael J. Wysocki]

Hi,

The following three patches contain minor freezer cleanups.  Please have a
look.

Greetings,
Rafael

[PATCH 1/3] Freezer: Use __set_current_state in refrigerator

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Use __set_current_state() as appropriate in refrigerator() instead of accessing
current->state directly.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 kernel/power/process.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6.22-rc2/kernel/power/process.c
===================================================================
--- linux-2.6.22-rc2.orig/kernel/power/process.c
+++ linux-2.6.22-rc2/kernel/power/process.c
@@ -72,7 +72,7 @@ void refrigerator(void)
 		schedule();
 	}
 	pr_debug("%s left refrigerator\n", current->comm);
-	current->state = save;
+	__set_current_state(save);
 }
 
 static void freeze_task(struct task_struct *p)

Re: [PATCH 1/3] Freezer: Use __set_current_state in refrigerator

[Pavel Machek]

On Sat 2007-05-26 23:20:59, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Use __set_current_state() as appropriate in refrigerator() instead of accessing
> current->state directly.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
ACK.

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

[PATCH 2/3] Freezer: Return int from freeze_processes

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Make try_to_freeze_tasks() and freeze_processes() return -EBUSY on failure
instead of the number of unfrozen tasks (none of the callers actually uses this
number).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 kernel/power/process.c |   21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

Index: linux-2.6.22-rc2/kernel/power/process.c
===================================================================
--- linux-2.6.22-rc2.orig/kernel/power/process.c
+++ linux-2.6.22-rc2/kernel/power/process.c
@@ -105,7 +105,7 @@ static void cancel_freezing(struct task_
 	}
 }
 
-static unsigned int try_to_freeze_tasks(int freeze_user_space)
+static int try_to_freeze_tasks(int freeze_user_space)
 {
 	struct task_struct *g, *p;
 	unsigned long end_time;
@@ -175,28 +175,25 @@ static unsigned int try_to_freeze_tasks(
 		read_unlock(&tasklist_lock);
 	}
 
-	return todo;
+	return todo ? -EBUSY : 0;
 }
 
 /**
  *	freeze_processes - tell processes to enter the refrigerator
- *
- *	Returns 0 on success, or the number of processes that didn't freeze,
- *	although they were told to.
  */
 int freeze_processes(void)
 {
-	unsigned int nr_unfrozen;
+	int error;
 
 	printk("Stopping tasks ... ");
-	nr_unfrozen = try_to_freeze_tasks(FREEZER_USER_SPACE);
-	if (nr_unfrozen)
-		return nr_unfrozen;
+	error = try_to_freeze_tasks(FREEZER_USER_SPACE);
+	if (error)
+		return error;
 
 	sys_sync();
-	nr_unfrozen = try_to_freeze_tasks(FREEZER_KERNEL_THREADS);
-	if (nr_unfrozen)
-		return nr_unfrozen;
+	error = try_to_freeze_tasks(FREEZER_KERNEL_THREADS);
+	if (error)
+		return error;
 
 	printk("done.\n");
 	BUG_ON(in_atomic());

Re: [PATCH 2/3] Freezer: Return int from freeze_processes

[Pavel Machek]

On Sat 2007-05-26 23:24:34, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Make try_to_freeze_tasks() and freeze_processes() return -EBUSY on failure
> instead of the number of unfrozen tasks (none of the callers actually uses this
> number).
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

ACK.
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

[PATCH 3/3] Freezer: Remove redundant check in try_to_freeze_tasks

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

We don't need to check if todo is positive before calling time_after() in
try_to_freeze_tasks(), because if todo is zero at this point, the loop will
be broken anyway due to the while () condition being false.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 kernel/power/process.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6.22-rc2/kernel/power/process.c
===================================================================
--- linux-2.6.22-rc2.orig/kernel/power/process.c
+++ linux-2.6.22-rc2/kernel/power/process.c
@@ -149,7 +149,7 @@ static int try_to_freeze_tasks(int freez
 		} while_each_thread(g, p);
 		read_unlock(&tasklist_lock);
 		yield();			/* Yield is okay here */
-		if (todo && time_after(jiffies, end_time))
+		if (time_after(jiffies, end_time))
 			break;
 	} while (todo);
 

Re: [PATCH 3/3] Freezer: Remove redundant check in try_to_freeze_tasks

[Pavel Machek]

On Sat 2007-05-26 23:29:07, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> We don't need to check if todo is positive before calling time_after() in
> try_to_freeze_tasks(), because if todo is zero at this point, the loop will
> be broken anyway due to the while () condition being false.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

ACK. Thanks for the cleanups!
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html