Re: [PATCH v1 03/22] perf metrics: Don't scale counts going into metrics

[Xing Zhengjun]

On 9/28/2022 3:21 PM, Ian Rogers wrote:
> Counts are scaled prior to going into saved_value, reverse the scaling
> so that metrics don't double scale values.
>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
>   tools/perf/util/stat-shadow.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
> index 9e1eddeff21b..b5cedd37588f 100644
> --- a/tools/perf/util/stat-shadow.c
> +++ b/tools/perf/util/stat-shadow.c
> @@ -865,11 +865,16 @@ static int prepare_metric(struct evsel **metric_events,
>   			if (!v)
>   				break;
>   			stats = &v->stats;
> -			scale = 1.0;
> +			/*
> +			 * If an event was scaled during stat gathering, reverse
> +			 * the scale before computing the metric.
> +			 */
> +			scale = 1.0 / metric_events[i]->scale;
> +
This look likes not work for kernel side events like 
/sys/devices/uncore_imc_*/events/cas_count_read(write).

>   			source_count = evsel__source_count(metric_events[i]);
>   
>   			if (v->metric_other)
> -				metric_total = v->metric_total;
> +				metric_total = v->metric_total * scale;
>   		}
>   		n = strdup(evsel__metric_id(metric_events[i]));
>   		if (!n)

--
Zhengjun Xing