On Tue, Aug 11, 2015 at 06:38:05AM -0700, Andi Kleen wrote:
> On Tue, Aug 11, 2015 at 03:25:32PM +0200, Jiri Olsa wrote:
> > On Fri, Aug 07, 2015 at 06:06:18PM -0700, Andi Kleen wrote:
> > > From: Andi Kleen <a...@linux.intel.com>
> > >
> > > TopDown needs to multiply events by constants (for example
> > > the CPU Pipeline Width) to get the correct results.
> > > The kernel needs to export this factor.
> > >
> > > Today *.scale is only used to scale down metrics (divide), for example
> > > to scale bytes to MB.
> > >
> > > Repurpose negative scale to mean scaling up, that is multiplying.
> > > Implement the code for this in perf stat.
> > >
> > > Signed-off-by: Andi Kleen <a...@linux.intel.com>
> > > ---
> > > tools/perf/builtin-stat.c | 27 +++++++++++++++++++--------
> > > 1 file changed, 19 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> > > index ea5298a..2590c75 100644
> > > --- a/tools/perf/builtin-stat.c
> > > +++ b/tools/perf/builtin-stat.c
> > > @@ -179,6 +179,17 @@ static inline int nsec_counter(struct perf_evsel
> > > *evsel)
> > > return 0;
> > > }
> > >
> > > +static double scale_val(struct perf_evsel *counter, u64 val)
> > > +{
> > > + double uval = val;
> > > +
> > > + if (counter->scale < 0)
> > > + uval = val * (-counter->scale);
> > > + else if (counter->scale)
> > > + uval = val / counter->scale;
> >
> > hum, do you change the scale logic? the current scale > 0 works like:
> >
> > uval = val * counter->scale;
>
> Yes I define negative scales to mean "multiply by" See the description of the
> kernel
> patch for more details.
how about existing scale attributes, like in rapl code
jirka
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