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Date: Tue, 18 Oct 2011 21:48:51 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Simon Kirby <sim@hostway.ca>
cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Linus Torvalds <torvalds@linux-foundation.org>,
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        Martin Schwidefsky <schwidefsky@de.ibm.com>,
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Subject: Re: Linux 3.1-rc9
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On Tue, 18 Oct 2011, Simon Kirby wrote:
> Looks good running on three boxes since this morning (unpatched kernel
> hangs in ~15 minutes).
> 
> While I have your eyes, does this hang trace make any sense (which
> happened a couple of times with your previous patch applied)?
> 
> http://0x.ca/sim/ref/3.1-rc9/3.1-rc9-tcp-lockup.log
> 
> I don't see how all CPUs could be spinning on the same lock without
> reentry, and I don't see the any in the backtraces.

Weird.

Which version of Peters patches was this, the extra lock or the
atomic64 thingy?

It does not look related. Could you try to reproduce that problem with
lockdep enabled? lockdep might make it go away, but it's definitely
worth a try.

Thanks,

	tglx