Re: [PATCH] perf/x86: check ucode before disabling PEBS onSandyBridge

[Ingo Molnar]

* Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Thu, 2012-06-07 at 12:48 +0200, Stephane Eranian wrote:
> > >> The warning could also be done on boot. But the check has to be done
> > >>  when the event is created.
> > >
> > > Is this because of the ucode loader not having done its thing yet etc..?
> 
> Ah, its because you can update ucode at runtime of course.
> 
> A quick look at the ucode loader doesn't show it having a 
> notifier either, so then yeah we need to check on every event 
> creation :/
> 
> Or we could put a hook in the ucode loader.

I'd really suggest the latter - I doubt this will be our only 
ucode dependent quirk, going forward ...

Thanks,

	Ingo
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