linux-kernel - Re: x86, nops settings result in kernel crash

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Message-ID: <20120816134834.GA11974@x1.osrc.amd.com>
Date:	Thu, 16 Aug 2012 15:48:34 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Tomas Racek <tracek@...hat.com>
Cc:	"H. Peter Anvin" <hpa@...ux.intel.com>,
	Alan Cox <alan@...ux.intel.com>, linux-kernel@...r.kernel.org,
	qemu-devel@...gnu.org
Subject: Re: x86, nops settings result in kernel crash

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.
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