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From: Nageswara R Sastry <rnsastry@linux.vnet.ibm.com>
To: Johannes Weiner <hannes@saeurebad.de>
Cc: linux-kernel@vger.kernel.org, balbir@linux.vnet.ibm.com,
	ego@linux.vnet.ibm.com, svaidy@linux.vnet.ibm.com,
	davej@codemonkey.org.uk
Subject: Re: [BUG] While changing the cpufreq governor, kernel hits a bug in workqueue.c
Date: Mon, 07 Jul 2008 15:18:07 +0530	[thread overview]
Message-ID: <4871E657.3040403@linux.vnet.ibm.com> (raw)
In-Reply-To: <87fxqp7nye.fsf@skyscraper.fehenstaub.lan>

Hi Johannes,
>>> =======================================================
>>> [ INFO: possible circular locking dependency detected ]
>>> 2.6.25.7.cpufreq_patch #2
>>> -------------------------------------------------------
[...]
>> Okay, the problem is in cpufreq_conservative.c.  We
>> cancel_delayed_work_sync() while holding the mutex, but the work itself
>> tries to grab it and there it deadlocks; lockdep caught that right.
>>
>> The hunk for _ondemand is correct, but the one for _conservative is
>> obviously wrong, sorry :/
>>
>> I will whip something up and get back to you.  Thanks a lot for
>> testing!
> 
> Could you try the attached patch instead of the one above?
> 
> Dave, I dropped the mutex-grabbing from the conservative worker function
> as well as I don't see a reason for it, please correct me if I'm wrong.
> 
> 	Hannes
> 

The script is running now for more than 6 hours successfully, I will 
continue this and let you know if there are any failures.

* I am seeing the circular locking dependency with the above patch too.

Thanks!!
Regards
R.Nageswara Sastry

  reply	other threads:[~2008-07-07  9:50 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-23 10:51 [BUG] While changing the cpufreq governor, kernel hits a bug in workqueue.c Nageswara R Sastry
2008-06-23 15:26 ` Johannes Weiner
2008-06-24  9:17   ` Nageswara R Sastry
2008-06-25 19:47     ` Johannes Weiner
2008-06-25 20:00       ` Dave Jones
2008-06-26 12:18       ` Nageswara R Sastry
2008-06-26 13:31         ` Nageswara R Sastry
2008-06-27  4:12           ` Nageswara R Sastry
2008-07-01 14:00         ` Johannes Weiner
2008-07-04 13:56           ` Johannes Weiner
2008-07-07  9:48             ` Nageswara R Sastry [this message]
2008-07-07 11:07               ` Johannes Weiner
2008-07-08  5:52                 ` Nageswara R Sastry
2008-07-10 11:11                   ` Johannes Weiner
2008-07-15  3:42                     ` Nageswara R Sastry
2008-07-16 13:44                     ` Peter Zijlstra
2008-08-12  8:12                       ` Nageswara R Sastry
2008-08-12 21:29                         ` Johannes Weiner
2008-08-12 21:44                           ` Johannes Weiner
2008-10-07  9:41                             ` Nageswara R Sastry
2008-10-28  3:29                               ` Nageswara R Sastry
2008-07-07 11:19               ` Nageswara R Sastry

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