Re: [PATCH 5/9] perf stat: Fix --metric-only --json output

[Namhyung Kim]

Hi Arnaldo,

On Tue, Nov 8, 2022 at 12:45 PM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> Em Mon, Nov 07, 2022 at 01:33:10PM -0800, Namhyung Kim escreveu:
> > Currently it prints all metric headers for JSON output.  But actually it
> > skips some metrics with valid_only_metric().  So the output looks like:
> >
> >   $ perf stat --metric-only --json true
> >   {"unit" : "CPUs utilized", "unit" : "/sec", "unit" : "/sec", "unit" : "/sec", "unit" : "GHz", "unit" : "insn per cycle", "unit" : "/sec", "unit" : "branch-misses of all branches"}
> >   {"metric-value" : "3.861"}{"metric-value" : "0.79"}{"metric-value" : "3.04"}
> >
> > As you can see there are 8 units in the header but only 3 metric-values
> > are there.  It should skip the unused headers as well.  Also each unit
> > should be printed as a separate object like metric values.
> >
> > With this patch:
> >
> >   $ perf stat --metric-only --json true
> >   {"unit" : "GHz"}{"unit" : "insn per cycle"}{"unit" : "branch-misses of all branches"}
> >   {"metric-value" : "4.166"}{"metric-value" : "0.73"}{"metric-value" : "2.96"}
>
> Can we get a Fixes tag for this one?

I think this is it:

df936cadfb58 ("perf stat: Add JSON output option")

But this also depends on patch 4.  Do you want me to rebase
this not to depend on it?

Thanks,
Namhyung

>
> > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> > ---
> >  tools/perf/util/stat-display.c | 22 +++-------------------
> >  1 file changed, 3 insertions(+), 19 deletions(-)
> >
> > diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
> > index 115477461224..515fb6db3d67 100644
> > --- a/tools/perf/util/stat-display.c
> > +++ b/tools/perf/util/stat-display.c
> > @@ -430,12 +430,12 @@ static void print_metric_header(struct perf_stat_config *config,
> >           os->evsel->priv != os->evsel->evlist->selected->priv)
> >               return;
> >
> > -     if (!valid_only_metric(unit) && !config->json_output)
> > +     if (!valid_only_metric(unit))
> >               return;
> >       unit = fixunit(tbuf, os->evsel, unit);
> >
> >       if (config->json_output)
> > -             fprintf(os->fh, "\"unit\" : \"%s\"", unit);
> > +             fprintf(os->fh, "{\"unit\" : \"%s\"}", unit);
> >       else if (config->csv_output)
> >               fprintf(os->fh, "%s%s", unit, config->csv_sep);
> >       else
> > @@ -847,10 +847,6 @@ static void print_metric_headers(struct perf_stat_config *config,
> >               .new_line = new_line_metric,
> >               .force_header = true,
> >       };
> > -     bool first = true;
> > -
> > -     if (config->json_output && !config->interval)
> > -             fprintf(config->output, "{");
> >
> >       if (prefix && !config->json_output)
> >               fprintf(config->output, "%s", prefix);
> > @@ -871,18 +867,12 @@ static void print_metric_headers(struct perf_stat_config *config,
> >       evlist__for_each_entry(evlist, counter) {
> >               os.evsel = counter;
> >
> > -             if (!first && config->json_output)
> > -                     fprintf(config->output, ", ");
> > -             first = false;
> > -
> >               perf_stat__print_shadow_stats(config, counter, 0,
> >                                             0,
> >                                             &out,
> >                                             &config->metric_events,
> >                                             &rt_stat);
> >       }
> > -     if (config->json_output)
> > -             fprintf(config->output, "}");
> >       fputc('\n', config->output);
> >  }
> >
> > @@ -954,14 +944,8 @@ static void print_interval(struct perf_stat_config *config,
> >               }
> >       }
> >
> > -     if ((num_print_interval == 0 || config->interval_clear)
> > -                      && metric_only && !config->json_output)
> > +     if ((num_print_interval == 0 || config->interval_clear) && metric_only)
> >               print_metric_headers(config, evlist, " ", true);
> > -     if ((num_print_interval == 0 || config->interval_clear)
> > -                      && metric_only && config->json_output) {
> > -             fprintf(output, "{");
> > -             print_metric_headers(config, evlist, " ", true);
> > -     }
> >       if (++num_print_interval == 25)
> >               num_print_interval = 0;
> >  }
> > --
> > 2.38.1.431.g37b22c650d-goog
>
> --
>
> - Arnaldo