static void print_metric_begin(struct perf_stat_config *config,
                               struct evlist *evlist,
-                              const char *prefix, int aggr_idx,
-                              struct cgroup *cgrp)
+                              struct outstate *os, int aggr_idx)
 {
        struct perf_stat_aggr *aggr;
        struct aggr_cpu_id id;
        if (!config->metric_only)
                return;
 
-       if (prefix)
-               fprintf(config->output, "%s", prefix);
+       if (os->prefix)
+               fprintf(config->output, "%s", os->prefix);
 
        evsel = evlist__first(evlist);
        id = config->aggr_map->map[aggr_idx];
        aggr = &evsel->stats->aggr[aggr_idx];
        aggr_printout(config, evsel, id, aggr->nr);
 
-       print_cgroup(config, cgrp);
+       print_cgroup(config, os->cgrp);
 }
 
 static void print_metric_end(struct perf_stat_config *config)
                       const char *prefix)
 {
        struct evsel *counter;
+       struct outstate os = {
+               .prefix = prefix,
+       };
        int s;
 
        if (!config->aggr_map || !config->aggr_get_id)
         * Without each counter has its own line.
         */
        for (s = 0; s < config->aggr_map->nr; s++) {
-               print_metric_begin(config, evlist, prefix, s, /*cgrp=*/NULL);
+               print_metric_begin(config, evlist, &os, s);
 
                evlist__for_each_entry(evlist, counter) {
                        if (counter->merged_stat)
                              const char *prefix)
 {
        struct evsel *counter, *evsel;
-       struct cgroup *cgrp = NULL;
+       struct outstate os = {
+               .prefix = prefix,
+       };
        int s;
 
        if (!config->aggr_map || !config->aggr_get_id)
                return;
 
        evlist__for_each_entry(evlist, evsel) {
-               if (cgrp == evsel->cgrp)
+               if (os.cgrp == evsel->cgrp)
                        continue;
 
-               cgrp = evsel->cgrp;
+               os.cgrp = evsel->cgrp;
 
                for (s = 0; s < config->aggr_map->nr; s++) {
-                       print_metric_begin(config, evlist, prefix, s, cgrp);
+                       print_metric_begin(config, evlist, &os, s);
 
                        evlist__for_each_entry(evlist, counter) {
                                if (counter->merged_stat)
                                        continue;
 
-                               if (counter->cgrp != cgrp)
+                               if (counter->cgrp != os.cgrp)
                                        continue;
 
                                print_counter_aggrdata(config, counter, s, prefix);
 {
        int all_idx;
        struct perf_cpu cpu;
+       struct outstate os = {
+               .prefix = prefix,
+       };
 
        perf_cpu_map__for_each_cpu(cpu, all_idx, evlist->core.user_requested_cpus) {
                struct evsel *counter;
 
                        id = aggr_cpu_id__cpu(cpu, /*data=*/NULL);
                        if (first) {
-                               print_metric_begin(config, evlist, prefix,
-                                                  counter_idx, /*cgrp=*/NULL);
+                               print_metric_begin(config, evlist, &os, counter_idx);
                                first = false;
                        }
                        val = ps->aggr[counter_idx].counts.val;
 static void print_cgroup_counter(struct perf_stat_config *config, struct evlist *evlist,
                                 const char *prefix)
 {
-       struct cgroup *cgrp = NULL;
        struct evsel *counter;
+       struct outstate os = {
+               .prefix = prefix,
+       };
 
        evlist__for_each_entry(evlist, counter) {
-               if (cgrp != counter->cgrp) {
-                       if (cgrp != NULL)
+               if (os.cgrp != counter->cgrp) {
+                       if (os.cgrp != NULL)
                                print_metric_end(config);
 
-                       cgrp = counter->cgrp;
-                       print_metric_begin(config, evlist, prefix,
-                                          /*aggr_idx=*/0, cgrp);
+                       os.cgrp = counter->cgrp;
+                       print_metric_begin(config, evlist, &os, /*aggr_idx=*/0);
                }
 
                print_counter(config, counter, prefix);
        }
-       if (cgrp)
+       if (os.cgrp)
                print_metric_end(config);
 }
 
                } else if (config->cgroup_list) {
                        print_cgroup_counter(config, evlist, os.prefix);
                } else {
-                       print_metric_begin(config, evlist, os.prefix,
-                                          /*aggr_idx=*/0, /*cgrp=*/NULL);
+                       print_metric_begin(config, evlist, &os, /*aggr_idx=*/0);
                        evlist__for_each_entry(evlist, counter) {
                                print_counter(config, counter, os.prefix);
                        }