Re: [Bug #13058] First hibernation attempt fails

Alan Jenkins
2009-04-17T09:38:00Z

Jens Axboe wrote:
> On Fri, Apr 17 2009, Jens Axboe wrote:
>
>> On Fri, Apr 17 2009, Alan Jenkins wrote:
>>
>>> Jens Axboe wrote:
>>>
>>>> On Thu, Apr 16 2009, Rafael J. Wysocki wrote:
>>>>
>>>>
>>>>> This message has been generated automatically as a part of a report
>>>>> of recent regressions.
>>>>>
>>>>> The following bug entry is on the current list of known regressions
>>>>> from 2.6.29. Please verify if it still should be listed and let me know
>>>>> (either way).
>>>>>
>>>>>
>>>>> Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=13058
>>>>> Subject : First hibernation attempt fails
>>>>> Submitter : Alan Jenkins <alan-jenkins@tuffmail.co.uk>
>>>>> Date : 2009-04-10 10:58 (7 days old)
>>>>> First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1faa16d22877f4839bd433547d770c676d1d964c
>>>>> References : http://marc.info/?l=linux-kernel&m=123928022321917&w=2
>>>>>
>>>>>
>>>> Alan, is this still a problem?
>>>>
>>>>
>>> Yup. Still present in v2.6.30-rc2-195-g9f76208.
>>>
>> Given the somewhat odd nature of the bug and the requirements to trigger
>> it, how confident are you in the bisection results?
>>
>> I'll try and reproduce it here.
>>
>
> I can't reproduce it here. It seems very odd that an ENOMEM would happen
> as a consequence of the rq allocation change, it doesn't really change
> the allocation at all (and it'll never return -ENOMEM).
>
> Can you please recheck the git bisect results. It'd be nice if the
> hibernation failure would actually log where the problem occured...
>

Once I found the right conditions (wireless disabled and a specific KDE
session), it was 100% reproducible.

Reverting your commit fixed the problem. I can do another test of that
if you like.

My _bisection_ was not absolute, rock-solid certain because I only found
the right conditions half-way through. There's always the possibility I
would get different results if I redid it properly, from the start. But
I have some experience of this and took care to re-validate my upper &
lower bounds.