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Subject: Re: [RFC PATCH 2/2] perf stat: Use event group to simulate PMI on
 PMI-less hardware counter
From: Zhang Rui <rui.zhang@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "Lin, Ming M" <ming.m.lin@intel.com>, Ingo Molnar <mingo@elte.hu>,
        Matt Fleming <matt@console-pimps.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        lkml <linux-kernel@vger.kernel.org>,
        Arnaldo Carvalho de Melo <acme@redhat.com>
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Date: Fri, 12 Nov 2010 08:32:44 +0800
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On Thu, 2010-11-11 at 20:46 +0800, Peter Zijlstra wrote:
> On Thu, 2010-11-11 at 10:00 +0800, Zhang Rui wrote:
> > Well, the RAPL package energy perf event may need this piece of code.
> > 
> >  "MSR_PKG_ENERGY_STATUS is a read-only MSR. It reports the actual energy
> > use for the package domain. This MSR is updated every ~1msec. It has a
> > wraparound time of around 60 secs when power consumption is high, and
> > may be longer otherwise."
> > 
> > As it's an energy counter, we should show it in "perf stat", right?
> > As it doesn't have interrupt, I want to schedule a timer interrupt every
> > 30s to update the event counter. 
> 
> So use a timer inside the RAPL pmu driver. No need to change the
> interface or add generic code.

Okay.
I was wondering if this can be done with the current perf framework.
If not, surely I'm okay with using a timer inside RAPL driver. :)

thanks,
rui