linux-kernel - Re: Drop WARN on AMD lack of perfctrs

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Date:	Thu, 16 May 2013 23:34:20 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Robert Richter <rric@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>
Cc:	Josh Boyer <jwboyer@...hat.com>, Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	x86@...nel.org, linux-kernel@...r.kernel.org, gleb@...hat.com
Subject: Re: Drop WARN on AMD lack of perfctrs

On Thu, May 16, 2013 at 10:55:58PM +0200, Robert Richter wrote:
> iirc the reason was the different msr range that is switched on fam15h
> with a different counter to counter msr offset of 2 instead of 1. The
> code relies on the assumption that the msrs exist on that cpu. Thus
> the warning if not. Also note that code may have changed in 3.10 in
> that area.

Stupid question: why is check_hw_exists() *after* the vendor-specific
counter detection code in init_hw_perf_events() even though it is
supposed to check whether hardware is emulated?

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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