Subject: Re: nmi_watchdog=2 regression in 2.6.21
From: Daniel Walker <dwalker@mvista.com>
To: eranian@hpl.hp.com
Cc: B.Steinbrink@gmx.de, ak@suse.de, linux-kernel@vger.kernel.org,
       akpm@linux-foundation.org
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Date: Wed, 29 Aug 2007 18:21:59 -0700
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On Wed, 2007-08-29 at 14:24 -0700, Stephane Eranian wrote:


> Now on Core Duo, there is no PEBS anyway, so it is okay to use counter 0
> for NMI. The problem is that the detection code in perfctr-watchdog.c
> treats a Core Duo and a Core 2 Duo the same way as they both have the
> X86_FEATURE_ARCH_PERFMON bit set.
> 
> I have attached a patch with handle the case of the Core Duo. Unfortunately,
> I do not own one so I cannot test it. I would appreciate if you could
> try re-applying my counter 0 -> 1 patch + this new one to see if you
> have the problem with the NMI getting stuck.

I tested your patch .. The system doesn't hang, but the NMI seems to
disappear .. The check_nmi_watchdog() is not called, and the NMI never
actually starts firing .. Is that what you had intended?

Daniel

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