Hi,
The following patches add a new testing facility for suspend and hibernation.
The first patch adds the possibility to test the suspend (STD) core code

without actually suspending, which is useful for tracking problems with drivers

etc.
The second one modifies the hibernation core so that it can use the same

facility (it's a bit more powerful than the existing hibernation test modes,

since they really can't test the ACPI global methods).
The third one modified documentation in accordance with the two previous ones.
Comments welcome.
Greetings,

Rafael
--

"Premature optimization is the root of all evil." - Donald Knuth
-

From: Rafael J. Wysocki <rjw@sisk.pl>
Update the suspend/hibernation debugging and testing documentation to describe

the newly introduced testing facilities.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

---

 Documentation/power/basic-pm-debugging.txt |  188 ++++++++++++++++++++---------

 Documentation/power/drivers-testing.txt    |   28 ++--

 2 files changed, 149 insertions(+), 67 deletions(-)
Index: linux-2.6/Documentation/power/drivers-testing.txt

===================================================================

--- linux-2.6.orig/Documentation/power/drivers-testing.txt

+++ linux-2.6/Documentation/power/drivers-testing.txt

@@ -6,9 +6,9 @@ Testing suspend and resume support in de

 Unfortunately, to effectively test the support for the system-wide suspend and

 resume transitions in a driver, it is necessary to suspend and resume a fully

 functional system with this driver loaded.  Moreover, that should be done

-several times, preferably several times in a row, and separately for the suspend

-to disk (STD) and the suspend to RAM (STR) transitions, because each of these

-cases involves different ordering of operations and different interactions with

+several times, preferably several times in a row, and separately for hibernation

+(aka suspend to disk or STD) and suspend to RAM (STR), because each of these

+cases involves slightly different operations and different interactions with

 the machine's BIOS.
 Of course, for this purpose the test system has to be known to suspend and

@@ -22,20 +22,24 @@ for more information about the debugging

 Once you have resolved the suspend/resume-related problems with your test system

 without the new driver, you are ready to test it:
-a) Build the driver as a module, load it and try the STD in the test mode (see:

-Documents/power/basic-pm-debugging.txt, 1a)).

+a) Build the driver as a module, load it and try the test modes of hibernation

+(see: Documents/power/basic-pm-debugging.txt, 1)).
-b) Load the driver and attempt...
[ message continues ]

From: Rafael J. Wysocki <rjw@sisk.pl>
Make it possible to test the hibernation core code with the help of the

/sys/power/pm_test_level attribute introduced for suspend testing in the

previous patch.
Writing a number (1-5) to this file causes the hibernation code to work in one

of the test modes defined as follows:
5 - test the freezing of processes

4 - test the freezing of processes and suspending of devices

3 - test the freezing of processes, suspending of devices and platform global

    control methods(*)

2 - test the freezing of processes, suspending of devices, platform global

    control methods(*) and the disabling of nonboot CPUs

1 - test the freezing of processes, suspending of devices, platform global

    control methods(*), the disabling of nonboot CPUs and suspending of

    platform/system devices
(*) - the platform global control methods are only available on ACPI systems

      and are only tested if the hibernation mode is set to "platform"
Then, if a hibernation is started by normal means, the hibernation core will

perform its normal operations up to the point indicated by the test level.

Next, it will wait for 5 seconds and carry out the resume operations needed to

transition the system back to the fully functional state.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

---

 kernel/power/disk.c  |   70 ++++++++++++++++++++++++++++++++++++++++-----------

 kernel/power/power.h |    2 +

 2 files changed, 57 insertions(+), 15 deletions(-)
Index: linux-2.6/kernel/power/disk.c

===================================================================

--- linux-2.6.orig/kernel/power/disk.c

+++ linux-2.6/kernel/power/disk.c

@@ -70,6 +70,35 @@ void hibernation_set_ops(struct platform

 	mutex_unlock(&pm_mutex);

 }
+#ifdef CONFIG_PM_DEBUG

+static void hibernation_debug_sleep(void)

+{

+	printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");

+	mdelay(5000);

+}

+

+static int hibernation_testmode(int mode)

+{

+	if (hibernation_mode == mod...
[ message continues ]

From: Rafael J. Wysocki <rjw@sisk.pl>
Introduce /sys/power/pm_test_level attribute allowing one to test the suspend

core code.  Namely, writing a number (1-5) to this file causes the suspend code

to work in one of the test modes defined as follows:
5 - test the freezing of processes

4 - test the freezing of processes and suspending of devices

3 - test the freezing of processes, suspending of devices and platform global

    control methods

2 - test the freezing of processes, suspending of devices, platform global

    control methods and the disabling of nonboot CPUs

1 - test the freezing of processes, suspending of devices, platform global

    control methods, the disabling of nonboot CPUs and suspending of

    platform/system devices
Then, if a suspend is started by normal means, the suspend core will perform

its normal operations up to the point indicated by the test level.  Next, it

will wait for 5 seconds and carry out the resume operations needed to transition

the system back to the fully functional state.
Writing 0 to /sys/power/pm_test_level turns the testing off.  The current test

level may be read from /sys/power/pm_test_level .
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

---

 kernel/power/main.c  |   75 ++++++++++++++++++++++++++++++++++++++++++++-------

 kernel/power/power.h |   10 ++++++

 2 files changed, 76 insertions(+), 9 deletions(-)
Index: linux-2.6/kernel/power/main.c

===================================================================

--- linux-2.6.orig/kernel/power/main.c

+++ linux-2.6/kernel/power/main.c

@@ -28,6 +28,46 @@ BLOCKING_NOTIFIER_HEAD(pm_chain_head);
 DEFINE_MUTEX(pm_mutex);
+#ifdef CONFIG_PM_DEBUG

+int pm_test_level = TEST_NONE;

+

+static int suspend_test(int level)

+{

+	if (pm_test_level == level) {

+		printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");

+		mdelay(5000);

+		return 1;

+	}

+	return 0;

+}

+

+static ssize_t pm_test_level_show(struct kset *kset, char *buf)

+{

+	return sprintf(buf, "%d\...
[ message continues ]

ACK on whole series, but... should we also remove the old debugging

infrastructure? (Or did I just miss it?)

								Pavel

--

(english) http://www.livejournal.com/~pavelmachek

(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

-

Hi,
Well, I don't want to remove it just yet, but it's going to be deprecated.
Also, after Johannes' remark I thought it wouldn't be a good idea to export the

bare test levels to the user.  For this reason I reworked the patches to use

strings instead of numbers for the test setting (the attribute is now called

"pm_test" and is used in a similar way to "disk").
I'll post the reworked series as soon as I update the changelogs and docs.
Greetings,

Rafael

-

Without reading the code, I assume that this enum controls those levels.

I think a comment that it is user-space visible API and should not be

reordered would be warranted.
johannes

Yes, you are right.  I'll add the comment.
Thanks,

Rafael

-