perf stat: Convert perf_stat_evsel.res_stats array

It uses only one member, no need to have it as an array.

Reviewed-by: James Clark <james.clark@arm.com>
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: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220930202110.845199-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/stat-display.c

@@ -67,7 +67,7 @@ static void print_noise(struct perf_stat_config *config,
 		return;
 
 	ps = evsel->stats;
-	print_noise_pct(config, stddev_stats(&ps->res_stats[0]), avg);
+	print_noise_pct(config, stddev_stats(&ps->res_stats), avg);
 }
 
 static void print_cgroup(struct perf_stat_config *config, struct evsel *evsel)

tools/perf/util/stat.c

@@ -132,12 +132,9 @@ static void perf_stat_evsel_id_init(struct evsel *evsel)
 
 static void evsel__reset_stat_priv(struct evsel *evsel)
 {
-	int i;
 	struct perf_stat_evsel *ps = evsel->stats;
 
-	for (i = 0; i < 3; i++)
+	init_stats(&ps->res_stats);
-		init_stats(&ps->res_stats[i]);
-
 	perf_stat_evsel_id_init(evsel);
 }
 
@@ -437,7 +434,7 @@ int perf_stat_process_counter(struct perf_stat_config *config,
 	struct perf_counts_values *aggr = &counter->counts->aggr;
 	struct perf_stat_evsel *ps = counter->stats;
 	u64 *count = counter->counts->aggr.values;
-	int i, ret;
+	int ret;
 
 	aggr->val = aggr->ena = aggr->run = 0;
 
@@ -455,8 +452,7 @@ int perf_stat_process_counter(struct perf_stat_config *config,
 		evsel__compute_deltas(counter, -1, -1, aggr);
 	perf_counts_values__scale(aggr, config->scale, &counter->counts->scaled);
 
-	for (i = 0; i < 3; i++)
+	update_stats(&ps->res_stats, *count);
-		update_stats(&ps->res_stats[i], count[i]);
 
 	if (verbose > 0) {
 		fprintf(config->output, "%s: %" PRIu64 " %" PRIu64 " %" PRIu64 "\n",

tools/perf/util/stat.h

@@ -43,7 +43,7 @@ enum perf_stat_evsel_id {
 };
 
 struct perf_stat_evsel {
-	struct stats		 res_stats[3];
+	struct stats		 res_stats;
 	enum perf_stat_evsel_id	 id;
 	u64			*group_data;
 };