Re: [PATCH 2/9] perf, tools, stat: Support up-scaling of events

From: Jiri Olsa
Date: Tue Aug 11 2015 - 09:25:40 EST


On Fri, Aug 07, 2015 at 06:06:18PM -0700, Andi Kleen wrote:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> 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 <ak@xxxxxxxxxxxxxxx>
> ---
> 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;

jirka
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/