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Date: Tue, 15 Oct 2013 10:06:40 +0200
From: Knut Petersen <Knut_Petersen@t-online.de>
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CC: Linus Torvalds <torvalds@linux-foundation.org>,
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Subject: Re: [BUG 3.12.rc4] Oops: unable to handle kernel paging request during
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On 15.10.2013 02:59, Paul E. McKenney wrote:
> On Mon, Oct 14, 2013 at 04:16:03PM -0700, Paul E. McKenney wrote:
>> On Mon, Oct 14, 2013 at 11:52:48PM +0200, Knut Petersen wrote:
>>> On 14.10.2013 23:28, Paul E. McKenney wrote:
>>>> On Mon, Oct 14, 2013 at 10:53:03AM -0700, Linus Torvalds wrote:

>>>> I´ll run some tests with those debug parameters tomorrow. 
>>>> Any chance of a look at the .config file?
>>> Attached.
>> Thank you!  Looks like a pretty standard RCU setup.  Just to make sure
>> I saw it correctly -- you are running NR_CPUS=1?  Getting races to happen
>> in that mode is truly impressive!

Yes. The AOpen i915GMm-hfs  is a desktop board with mobile chipset for one Pentium-M.
As a musician I need an absolutely silent system, and the low power consumption of that
technology is a nice add-on.
> Ah, thing...  When running with only one CPU, both of synchronize_rcu_bh()
> and synchronize_sched() become essentially no-ops.  Anything that expected
> them to actually sleep would then break.
>
> However, because you are running with CONFIG_PREEMPT=y, synchronize_rcu()
> will still block.
>
> 							Thanx, Paul
>