Re: [PATCH -v3] perf, x86: try to handle unknown nmis with running perfctrs

From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>,
	Robert Richter <robert.richter@amd.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Lin Ming <ming.m.lin@intel.com>,
	"fweisbec@gmail.com" <fweisbec@gmail.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Huang, Ying" <ying.huang@intel.com>,
	Yinghai Lu <yinghai@kernel.org>, Andi Kleen <andi@firstfloor.org>
Subject: Re: [PATCH -v3] perf, x86: try to handle unknown nmis with running perfctrs
Date: Thu, 26 Aug 2010 01:36:54 +0400	[thread overview]
Message-ID: <20100825213654.GF14874@lenovo> (raw)
In-Reply-To: <20100825212037.GI4879@redhat.com>

On Wed, Aug 25, 2010 at 05:20:37PM -0400, Don Zickus wrote:
... 
> The only problem is only one counter is overflowing in these cases, so we
> would have to do it all the time, which may not be hard.  But I was
> thinking of something similar.
> 
> For now, I am trying to force counter0 off, seeing that most of the perf
> errata on nehalem have been on counter0.  Or maybe I can get 'perf top' to
> use something other than counter0 by running 'perf record' first?
> 
> Cheers,
> Don
> 
> > 
> > 	-- Cyrill
> 

Well, I never looked deep inside perf tool code itself. Perhaps the easiest
(if you want to disable counter0) is just disable it in kernel and see how
it goes, no?

	-- Cyrill