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Date: Mon, 21 Nov 2011 17:23:24 +0000
From: Will Deacon <will.deacon@arm.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "mingo@elte.hu" <mingo@elte.hu>, William Cohen <wcohen@redhat.com>,
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        Vince Weaver <vince@deater.net>
Subject: Re: [RFC][PATCH 2/6] perf, arch: Rework perf_event_index()
Message-ID: <20111121172323.GH20611@mudshark.cambridge.arm.com>
References: <20111121145114.049265181@chello.nl>
 <20111121145337.533322271@chello.nl>
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Hi Peter,

On Mon, Nov 21, 2011 at 02:51:16PM +0000, Peter Zijlstra wrote:
> Put the logic to compute the event index into a per pmu method. This
> is required because the x86 rules are weird and wonderful and don't
> match the capabilities of the current scheme.
> 
> AFAIK only powerpc actually has a usable userspace read of the PMCs
> but I'm not at all sure anybody actually used that.
> 
> ARM looks like it cared, but I really wouldn't know, Will?

It used to care, but it doesn't anymore. Feel free to make the offset 0 and
use the (now) generic codepath.

With that:

Acked-by: Will Deacon <will.deacon@arm.com>

Will