perf stat: Show average value on multiple runs

When -r option is used, perf stat runs the command multiple times and
update stats in the evsel->stats.res_stats for global aggregation.  But
the value is never used and the value it prints at the end is just the
value from the last run.  I think we should print the average number of
multiple runs.

Add evlist__copy_res_stats() to update the aggr counter (for display)
using the values in the evsel->stats.res_stats.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230616073211.1057936-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index 934f79778cea..325d0fad1842 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -197,6 +197,7 @@ void evlist__save_aggr_prev_raw_counts(struct evlist *evlist);
 
 int evlist__alloc_aggr_stats(struct evlist *evlist, int nr_aggr);
 void evlist__reset_aggr_stats(struct evlist *evlist);
+void evlist__copy_res_stats(struct perf_stat_config *config, struct evlist *evlist);
 
 int perf_stat_process_counter(struct perf_stat_config *config,
 			      struct evsel *counter);