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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [PATCH] Fix performance monitor exception in 2.6.20-series
Date: Sun, 14 Jan 2007 01:39:17 +0100
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@ozlabs.org, Livio Soares <livio@eecg.toronto.edu>
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> Well, are you absolutely sure that nothing will break as a result of
> having a PMU interrupt happening right when it's not expected to ?
>
> You are basically turning the PMU interrupt into an NMI... I'm not sure
> how safe that is.

That just depends what code is run from the PMU exception.
It very much makes sense *conceptually* to have it behave
like an NMI I think -- but yeah the code run from the
exception had better behave ;-)


Segher