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	 <1261502431.4937.38.camel@laptop>
Date: Tue, 22 Dec 2009 19:16:16 +0000
Message-ID: <74fd948d0912221116l477a8a71w1feadc1341fc6e21@mail.gmail.com>
Subject: Re: WARN_ON at line 380 in kernel/smp.c under 2.6.32.2 + TuxOnIce + 
	KDB
From: Pedro Ribeiro <pedrib@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
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On Tue, Dec 22, 2009 at 5:20 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Tue, 2009-12-22 at 16:51 +0000, Pedro Ribeiro wrote:
>> Hi all,
>>
>> I've been asked by Nigel Cunningham of TuxOnIce to forward this bug here.
>>
>> While resuming from hibernate (using TuxOnIce) I'm seeing the WARN_ON
>> at line 380 in kernel/smp.c trigger from a kmap_high call right after
>> secondary processors have been brought down (the previous message is
>> "CPU1 is down").
>>
>> I only have pictures of the backtrace (readable but not very good
>> quality, sorry).
>> http://img51.imageshack.us/img51/2312/stacktrace1.jpg
>> http://img195.imageshack.us/img195/3646/stacktrace2.jpg
>>
>> At first I thought this was related to my battery saving script
>> messing with /proc/sys/vm/dirty_writeback_centisecs, but I'm not sure
>> right now, it still happens with the default value, so I'm clueless.
>>
>> Mind you, this does not impede the resume - it just dumps this stack
>> trace and continues resuming happily.
>
> If you'd enable frame pointers the strack traces would be clearer, but
> it looks like a bug in tux on ice, doing kmap_high() with IRQs disabled
> or something like that.
>
>

Thanks for your reply.

I enabled frame pointers, is this more useful?
http://img684.imageshack.us/img684/5118/dsc01206m.jpg
http://img96.imageshack.us/img96/5493/dsc01207k.jpg
http://img33.imageshack.us/img33/7470/dsc01208lp.jpg

Regards,
Pedro
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