Re: [PATCH v2 0/3] perf,x86: add Intel RAPL PMU support

[Ingo Molnar <mingo@kernel.org>]

* Stephane Eranian <eranian@google.com> wrote:

> On Wed, Oct 16, 2013 at 7:53 PM, Arnaldo Carvalho de Melo
> <acme@redhat.com> wrote:
> > Em Wed, Oct 16, 2013 at 03:13:54PM +0200, Stephane Eranian escreveu:
> >> On Wed, Oct 16, 2013 at 2:46 PM, Ingo Molnar <mingo@kernel.org> wrote:
> >> > We should also tell user-space that the unit of this counter is 'Joule'.
> >> >
> >> > Then things like:
> >> >
> >> >         perf stat -a -e power/* sleep 1
> >> >
> >> > would output, without knowing any RAPL details:
> >> >
> >> >             0.20619 Joule    power/energy-core
> >> >             2.42151 Joule    power/energy-pkg
> >> >
> >> Not sure there is already some support for this in perf stat. Arnaldo?
> >
> > Nope, there is not, we would have to have some table somewhere with
> > "event-regexp: unit-string"
> >
> >> If not that we need another sysfs file to export the unit. Another
> >> possibility is for perf stat to recognize the power/* and extract the
> >> unit from the event name. In my example power/joules-cores -> joules.
> >
> > I.e. you would be encoding the counter unit as the suffix, might as well
> > call it "power/cores.joules" and use the dot as the separator for the
> > unit, but would be just a compact form to encode the counter->unit
> > table.
>
> May be easier to add a sysfs entry with the unit to display.

Yes - with no entry meaning a raw 'count' or such.

Thanks,

	Ingo