Re: [PATCH] perf, x86: try to handle unknown nmis with runningperfctrs

[Don Zickus]

On Mon, Aug 09, 2010 at 09:48:29PM +0200, Robert Richter wrote:
> On 06.08.10 10:21:31, Don Zickus wrote:
> > On Fri, Aug 06, 2010 at 08:52:03AM +0200, Robert Richter wrote:
> 
> > > I was playing around with it yesterday trying to fix this. My idea is
> > > to skip an unkown nmi if the privious nmi was a *handled* perfctr
> > 
> > You might want to add a little more logic that says *handled* _and_ had
> > more than one perfctr trigger.  Most of the time only one perfctr is
> > probably triggering, so you might be eating unknown_nmi's needlessly.
> > 
> > Just a thought.
> 
> Yes, that's true. It could be implemented on top of the patch below.

I did, but the changes basically revert the bulk of your patch.

> 
> > 
> > > nmi. I will probably post an rfc patch early next week.
> 
> Here it comes:
> 
> From d2739578199d881ae6a9537c1b96a0efd1cdea43 Mon Sep 17 00:00:00 2001
> From: Robert Richter <robert.richter@xxxxxxx>
> Date: Thu, 5 Aug 2010 16:19:59 +0200
> Subject: [PATCH] perf, x86: try to handle unknown nmis with running perfctrs

On top of Robert's patch:
(compiled tested only because I don't have a fancy button to trigger
unknown nmis)