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

Robert Richter
2010-08-12T13:24:34Z

On 10.08.10 15:24:28, Cyrill Gorcunov wrote:
> On Tue, Aug 10, 2010 at 09:05:41PM +0200, Robert Richter wrote:
> > On 10.08.10 13:24:51, Cyrill Gorcunov wrote:
> >
> > > It gets masked on NMI arrival, at least for some models (Core Duo, P4,
> > > P6 M and I suspect more theh that, that was the reason oprofile has
> > > it, also there is a note in SDM V3a page 643).
> >
> > Yes, that's right, I never noticed that. Maybe it is better to
> > implement the apic write it in model specific code then.
> >
>
> Perhaps we can make it simplier I think, ie like it was before -- we just
> move it under your new DIE_NMIUNKNOWN, in separate patch of course. Though
> I'm fine with either way.

I do not understand why you want to put this in the 'unknown'
path. Isn't it necessary to unmask the vector with every call of the
nmi handler?

-Robert

>
> (actually it's interesting to know wouldn't we leave lvt masked when
> we hit 'second delayed nmi has arrived' situation, I guess we didn't
> hit it before in real yet :-)
>
> > -Robert
> >
> > --
> > Advanced Micro Devices, Inc.
> > Operating System Research Center
> >
> -- Cyrill
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Advanced Micro Devices, Inc.
Operating System Research Center