perf stat: Don't display metric header for non-leader uncore events

On an Intel tigerlake laptop a metric like:

    {
        "BriefDescription": "Test",
        "MetricExpr": "imc_free_running@data_read@ + imc_free_running@data_write@",
        "MetricGroup": "Test",
        "MetricName": "Test",
        "ScaleUnit": "6.103515625e-5MiB"
    },

Will have 4 events:

  uncore_imc_free_running_0/data_read/
  uncore_imc_free_running_0/data_write/
  uncore_imc_free_running_1/data_read/
  uncore_imc_free_running_1/data_write/

If aggregration is disabled with metric-only 2 column headers are
needed:

  $ perf stat -M test --metric-only -A -a sleep 1

   Performance counter stats for 'system wide':

                    MiB  Test            MiB  Test
  CPU0                 1821.0               1820.5

But when not, the counts aggregated in the metric leader and only 1
column should be shown:

  $ perf stat -M test --metric-only -a sleep 1
   Performance counter stats for 'system wide':

              MiB  Test
                5909.4

         1.001258915 seconds time elapsed

Achieve this by skipping events that aren't metric leaders when
printing column headers and aggregation isn't disabled.

The bug is long standing, the fixes tag is set to a refactor as that
is as far back as is reasonable to backport.

Fixes: 088519f318be3a41 ("perf stat: Move the display functions to stat-display.c")
Signed-off-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kaige Ye <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: K Prateek Nayak <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Yicong Yang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions