linux-kernel - Re: [PATCH v2 9/9] perf annotate: Use the sample period when calculating the percentage

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Date:   Wed, 19 Jul 2017 01:23:44 +0900
From:   Namhyung Kim <namhyung@...nel.org>
To:     Taeung Song <treeze.taeung@...il.com>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        linux-kernel@...r.kernel.org, Jiri Olsa <jolsa@...hat.com>,
        kernel-team@....com
Subject: Re: [PATCH v2 9/9] perf annotate: Use the sample period when
 calculating the percentage

On Fri, Jul 14, 2017 at 02:46:20AM +0900, Taeung Song wrote:
> Currently the percentages of perf-annotate are calculated
> with number of samples, not the sample period.
> So fix it to correspond with perf-report using the sample period
> for the calculation.

Not sure someone still wants the old behavior.  Maybe it'd be better
to honor --show-nr-samples option.


> 
> Cc: Namhyung Kim <namhyung@...nel.org>
> Cc: Jiri Olsa <jolsa@...hat.com>
> Signed-off-by: Taeung Song <treeze.taeung@...il.com>
> ---
>  tools/perf/util/annotate.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index d9bdedf..28a6d11 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -988,7 +988,7 @@ double disasm__calc_percent(struct annotation *notes, int evidx, s64 offset,
>  		if (h->total_samples) {

It seems checking total_period here is clearer and safer.  But I guess
it would have same effect 99.9% but still..


>  			sample->nr_samples = hits;
>  			sample->period = p;
> -			percent = 100.0 * hits / h->total_samples;
> +			percent = 100.0 * p / h->total_period;
>  		}
>  	}
>  
> @@ -1730,8 +1730,9 @@ static int symbol__get_source_line(struct symbol *sym, struct map *map,
>  	start = map__rip_2objdump(map, sym->start);
>  
>  	for (i = 0; i < len; i++) {
> -		u64 offset, nr_samples;
> +		u64 offset;
>  		double percent_max = 0.0;
> +		struct sym_hist_entry sample;
>  
>  		src_line->nr_pcnt = nr_pcnt;
>  
> @@ -1739,15 +1740,15 @@ static int symbol__get_source_line(struct symbol *sym, struct map *map,
>  			double percent = 0.0;
>  
>  			h = annotation__histogram(notes, evidx + k);
> -			nr_samples = h->addr[i].nr_samples;
> +			sample = h->addr[i];
>  
>  			if (h->total_samples)

Ditto.

Thanks,
Namhyung


> -				percent = 100.0 * nr_samples / h->total_samples;
> +				percent = 100.0 * sample.period / h->total_period;
>  
>  			if (percent > percent_max)
>  				percent_max = percent;
>  			src_line->samples[k].percent = percent;
> -			src_line->samples[k].nr = nr_samples;
> +			src_line->samples[k].nr = sample.nr_samples;
>  		}
>  
>  		if (percent_max <= 0.5)
> -- 
> 2.7.4
>