Bug 23422

Summary:	Freeze on entering hibernation on Thinkpad T41
Product:	Power Management	Reporter:	Björn Schließmann (chronoss)
Component:	Hibernation/Suspend	Assignee:	power-management_other
Status:	CLOSED INSUFFICIENT_DATA
Severity:	normal	CC:	rjw, rui.zhang
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.33 and later	Subsystem:
Regression:	Yes	Bisected commit-id:
Bug Depends on:
Bug Blocks:	7216

Description Björn Schließmann 2010-11-21 13:07:17 UTC

My Thinkpad T41 freezes approx. 20-50% of all hibernation attempts.

Steps to reproduce:

(1) start hibernation, e.g. "sudo pm-hibernate"

The "moon" LED blinks now. If all goes right, blinking stops shortly after and writing RAM to disk begins; computer turns off after this. If not, blinking stays indefinitely -- freeze. Magic Sysrq keys don't work either.

I first noticed it in my distro's (Ubuntu) 2.6.35 stock kernel. After bisecting (using the mainline vanilla kernel) for quite a while, I could find out the first commit where this appears (see below). Problem persists even in 2.6.36. I tried using help of /sys/power/pm_trace, but most of the time there was no hash match at all. The bug I filed in Launchpad (LP #623550) shows at least four other people affected. In another bug (LP #661711) about probably the same cause other Thinkpads and brands seem affected too.

| commit 7b51755c3b38483b574d363d5ee587283c3f7999
| Author: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
| Date:   Mon Dec 14 17:59:12 2009 -0800
| 
|     vmscan: kill hibernation specific reclaim logic and unify it

I'd like to help fixing this bug, but after looking at the commit I decided I'm not competent enough on how to go from here. How can I help?

Regards,


Björn

Comment 1 Rafael J. Wysocki 2010-11-21 23:18:26 UTC

When exactly does the box hang?  Is it before the image is created or after
that?

Is the system 32-bit or 64-bit?

Please do the test:

# echo core > /sys/power/pm_test
# echo disk > /sys/power/state

(it should return to the command prompt in 5-10 sec.) and see if you are
able to reproduce the symptoms.

Comment 2 Björn Schließmann 2010-11-22 16:57:00 UTC

I'm quite sure it freezes before image creation; see below.

The system is 32-bit (Pentium M 1,6 GHz).

Using your test I could reproduce the freeze, *but*:

- Just looping the test with 10 s sleep in between went well > 50 times (I canceled after that).

- Allocating 500 MB of memory for a process, doing the test and freeing/reallocating after "wakeup" proved successful after two(!) tries. It froze again.

(I allocated memory using a Python interpreter, i.e.:
>>> a=600000000*"a" # allocate
>>> a=None          # free)

Comment 3 Zhang Rui 2012-01-18 02:23:45 UTC

It's great that kernel bugzilla is back.

Björn,
can you please verify if the problem still exists in the latest upstream
kernel?

Comment 4 Zhang Rui 2012-05-24 07:40:25 UTC

bug closed as there is no response from the bug reporter.
please feel free to reopen it if the problem still exists in the latest upstream kernel.