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Date: Fri, 10 May 2013 13:10:17 -0700
From: Dave Hansen <dave@sr71.net>
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To: Peter Zijlstra <peterz@infradead.org>
CC: Andi Kleen <ak@linux.intel.com>, LKML <linux-kernel@vger.kernel.org>,
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Subject: Re: NMIs induced by 'perf top' hogging all CPU time
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On 05/10/2013 03:29 AM, Peter Zijlstra wrote:
> On Thu, May 09, 2013 at 04:29:16PM -0700, Dave Hansen wrote:
>> If I boot a recent kernel (bb9055b) and run 'perf top' on my machine, it
>> hangs.  It is 100% reproducible; it happens every single time.  If I'm
>> lucky, I'll get some of the hardlockup detection messages on the console.
> 
> Are you implicitly saying it worked as expected on previous kernels?

Yes, it works on older kernels.  3.6.11 works, for instance.

This hardware is quite effective at finding bugs.  It makes bisecting
very challenging as not a lot of random mainline versions boot.