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Date: Thu, 16 Aug 2012 15:48:34 +0200
From: Borislav Petkov <bp@alien8.de>
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Subject: Re: [Qemu-devel] x86, nops settings result in kernel crash
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To: Tomas Racek <tracek@redhat.com>
Cc: qemu-devel@nongnu.org, "H. Peter Anvin" <hpa@linux.intel.com>, linux-kernel@vger.kernel.org, Alan Cox <alan@linux.intel.com>

On Thu, Aug 16, 2012 at 09:35:12AM -0400, Tomas Racek wrote:
> Hi,
> 
> I am writing a file system test which I execute in qemu with kernel compiled from latest git sources and running it causes this error:
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=45971
> 
> It works with v3.5, so I ran git bisect which pointed me to:
> 
> d6250a3f12edb3a86db9598ffeca3de8b4a219e9 x86, nops: Missing break resulting in incorrect selection on Intel
> 
> To be quite honest, I don't understand this stuff much but I tried to do some debugging and I figured out (I hope) that the crash is caused by setting ideal_nops to p6_nops (k8_nops was used before the break statement was added).

Maybe I overlooked it or maybe it was implied but did you try reverting
the patch and rerunning your test? Does it work ok then?

Thanks.

-- 
Regards/Gruss,
Boris.