perf pmu-events: Don't assume pmu_event is an array
authorIan Rogers <irogers@google.com>
Fri, 12 Aug 2022 23:09:45 +0000 (16:09 -0700)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Sat, 13 Aug 2022 18:01:31 +0000 (15:01 -0300)
The current code assumes that a struct pmu_event can be iterated over
forward until a NULL pmu_event is encountered.

This makes it difficult to refactor pmu_event.

Add a loop function taking a callback function that's passed the struct
pmu_event.

This way the pmu_event is only needed for one element and not an entire
array.

Switch existing code iterating over the pmu_event arrays to use the new
loop function pmu_events_table_for_each_event.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220812230949.683239-11-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/pmu-events/empty-pmu-events.c
tools/perf/pmu-events/jevents.py
tools/perf/pmu-events/pmu-events.h
tools/perf/tests/pmu-events.c
tools/perf/util/metricgroup.c
tools/perf/util/pmu.c
tools/perf/util/s390-sample-raw.c

index 028f44e..bee1967 100644 (file)
@@ -247,6 +247,20 @@ static const struct pmu_sys_events pmu_sys_event_tables[] = {
        },
 };
 
+int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_iter_fn fn,
+                                   void *data)
+{
+       for (const struct pmu_event *pe = &table[0];
+            pe->name || pe->metric_group || pe->metric_name;
+            pe++) {
+               int ret = fn(pe, table, data);
+
+               if (ret)
+                       return ret;
+       }
+       return 0;
+}
+
 const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu)
 {
        const struct pmu_event *table = NULL;
@@ -291,14 +305,10 @@ int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data)
        for (const struct pmu_events_map *tables = &pmu_events_map[0];
             tables->table;
             tables++) {
-               for (const struct pmu_event *pe = &tables->table[0];
-                    pe->name || pe->metric_group || pe->metric_name;
-                    pe++) {
-                       int ret = fn(pe, &tables->table[0], data);
+               int ret = pmu_events_table_for_each_event(tables->table, fn, data);
 
-                       if (ret)
-                               return ret;
-               }
+               if (ret)
+                       return ret;
        }
        return 0;
 }
@@ -319,14 +329,10 @@ int pmu_for_each_sys_event(pmu_event_iter_fn fn, void *data)
        for (const struct pmu_sys_events *tables = &pmu_sys_event_tables[0];
             tables->name;
             tables++) {
-               for (const struct pmu_event *pe = &tables->table[0];
-                    pe->name || pe->metric_group || pe->metric_name;
-                    pe++) {
-                       int ret = fn(pe, &tables->table[0], data);
+               int ret = pmu_events_table_for_each_event(tables->table, fn, data);
 
-                       if (ret)
-                               return ret;
-               }
+               if (ret)
+                       return ret;
        }
        return 0;
 }
index 1a04b84..977f206 100755 (executable)
@@ -410,6 +410,20 @@ static const struct pmu_sys_events pmu_sys_event_tables[] = {
 \t},
 };
 
+int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_iter_fn fn,
+                                    void *data)
+{
+        for (const struct pmu_event *pe = &table[0];
+             pe->name || pe->metric_group || pe->metric_name;
+             pe++) {
+                int ret = fn(pe, table, data);
+
+                if (ret)
+                        return ret;
+        }
+        return 0;
+}
+
 const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu)
 {
         const struct pmu_event *table = NULL;
@@ -453,14 +467,10 @@ int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data)
         for (const struct pmu_events_map *tables = &pmu_events_map[0];
              tables->table;
              tables++) {
-                for (const struct pmu_event *pe = &tables->table[0];
-                     pe->name || pe->metric_group || pe->metric_name;
-                     pe++) {
-                        int ret = fn(pe, &tables->table[0], data);
+                int ret = pmu_events_table_for_each_event(tables->table, fn, data);
 
-                        if (ret)
-                                return ret;
-                }
+                if (ret)
+                        return ret;
         }
         return 0;
 }
@@ -481,14 +491,10 @@ int pmu_for_each_sys_event(pmu_event_iter_fn fn, void *data)
         for (const struct pmu_sys_events *tables = &pmu_sys_event_tables[0];
              tables->name;
              tables++) {
-                for (const struct pmu_event *pe = &tables->table[0];
-                     pe->name || pe->metric_group || pe->metric_name;
-                     pe++) {
-                        int ret = fn(pe, &tables->table[0], data);
+                int ret = pmu_events_table_for_each_event(tables->table, fn, data);
 
-                        if (ret)
-                                return ret;
-                }
+                if (ret)
+                        return ret;
         }
         return 0;
 }
index 485e730..7067284 100644 (file)
@@ -34,6 +34,9 @@ typedef int (*pmu_event_iter_fn)(const struct pmu_event *pe,
                                 const struct pmu_event *table,
                                 void *data);
 
+int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_iter_fn fn,
+                                   void *data);
+
 const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu);
 const struct pmu_event *find_core_events_table(const char *arch, const char *cpuid);
 int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data);
index a64497c..e308d48 100644 (file)
@@ -423,84 +423,104 @@ static int compare_alias_to_test_event(struct perf_pmu_alias *alias,
        return 0;
 }
 
-/* Verify generated events from pmu-events.c are as expected */
-static int test__pmu_event_table(struct test_suite *test __maybe_unused,
-                                int subtest __maybe_unused)
+static int test__pmu_event_table_core_callback(const struct pmu_event *pe,
+                                              const struct pmu_event *table __maybe_unused,
+                                              void *data)
 {
-       const struct pmu_event *sys_event_tables = find_sys_events_table("pme_test_soc_sys");
-       const struct pmu_event *table = find_core_events_table("testarch", "testcpu");
-       int map_events = 0, expected_events;
+       int *map_events = data;
+       struct perf_pmu_test_event const **test_event_table;
+       bool found = false;
 
-       /* ignore 3x sentinels */
-       expected_events = ARRAY_SIZE(core_events) +
-                         ARRAY_SIZE(uncore_events) +
-                         ARRAY_SIZE(sys_events) - 3;
+       if (!pe->name)
+               return 0;
 
-       if (!table || !sys_event_tables)
-               return -1;
+       if (pe->pmu)
+               test_event_table = &uncore_events[0];
+       else
+               test_event_table = &core_events[0];
 
-       for (; table->name; table++) {
-               struct perf_pmu_test_event const **test_event_table;
-               bool found = false;
+       for (; *test_event_table; test_event_table++) {
+               struct perf_pmu_test_event const *test_event = *test_event_table;
+               struct pmu_event const *event = &test_event->event;
 
-               if (table->pmu)
-                       test_event_table = &uncore_events[0];
-               else
-                       test_event_table = &core_events[0];
+               if (strcmp(pe->name, event->name))
+                       continue;
+               found = true;
+               (*map_events)++;
 
-               for (; *test_event_table; test_event_table++) {
-                       struct perf_pmu_test_event const *test_event = *test_event_table;
-                       struct pmu_event const *event = &test_event->event;
+               if (compare_pmu_events(pe, event))
+                       return -1;
 
-                       if (strcmp(table->name, event->name))
-                               continue;
-                       found = true;
-                       map_events++;
+               pr_debug("testing event table %s: pass\n", pe->name);
+       }
+       if (!found) {
+               pr_err("testing event table: could not find event %s\n", pe->name);
+               return -1;
+       }
+       return 0;
+}
 
-                       if (compare_pmu_events(table, event))
-                               return -1;
+static int test__pmu_event_table_sys_callback(const struct pmu_event *pe,
+                                             const struct pmu_event *table __maybe_unused,
+                                             void *data)
+{
+       int *map_events = data;
+       struct perf_pmu_test_event const **test_event_table;
+       bool found = false;
 
-                       pr_debug("testing event table %s: pass\n", table->name);
-               }
+       test_event_table = &sys_events[0];
 
-               if (!found) {
-                       pr_err("testing event table: could not find event %s\n",
-                              table->name);
-                       return -1;
-               }
-       }
+       for (; *test_event_table; test_event_table++) {
+               struct perf_pmu_test_event const *test_event = *test_event_table;
+               struct pmu_event const *event = &test_event->event;
 
-       for (table = sys_event_tables; table->name; table++) {
-               struct perf_pmu_test_event const **test_event_table;
-               bool found = false;
+               if (strcmp(pe->name, event->name))
+                       continue;
+               found = true;
+               (*map_events)++;
 
-               test_event_table = &sys_events[0];
+               if (compare_pmu_events(pe, event))
+                       return TEST_FAIL;
 
-               for (; *test_event_table; test_event_table++) {
-                       struct perf_pmu_test_event const *test_event = *test_event_table;
-                       struct pmu_event const *event = &test_event->event;
+               pr_debug("testing sys event table %s: pass\n", pe->name);
+       }
+       if (!found) {
+               pr_debug("testing sys event table: could not find event %s\n", pe->name);
+               return TEST_FAIL;
+       }
+       return TEST_OK;
+}
 
-                       if (strcmp(table->name, event->name))
-                               continue;
-                       found = true;
-                       map_events++;
+/* Verify generated events from pmu-events.c are as expected */
+static int test__pmu_event_table(struct test_suite *test __maybe_unused,
+                                int subtest __maybe_unused)
+{
+       const struct pmu_event *sys_event_table = find_sys_events_table("pme_test_soc_sys");
+       const struct pmu_event *table = find_core_events_table("testarch", "testcpu");
+       int map_events = 0, expected_events, err;
 
-                       if (compare_pmu_events(table, event))
-                               return -1;
+       /* ignore 3x sentinels */
+       expected_events = ARRAY_SIZE(core_events) +
+                         ARRAY_SIZE(uncore_events) +
+                         ARRAY_SIZE(sys_events) - 3;
 
-                       pr_debug("testing sys event table %s: pass\n", table->name);
-               }
-               if (!found) {
-                       pr_debug("testing event table: could not find event %s\n",
-                                  table->name);
-                       return -1;
-               }
-       }
+       if (!table || !sys_event_table)
+               return -1;
+
+       err = pmu_events_table_for_each_event(table, test__pmu_event_table_core_callback,
+                                             &map_events);
+       if (err)
+               return err;
+
+       err = pmu_events_table_for_each_event(sys_event_table, test__pmu_event_table_sys_callback,
+                                             &map_events);
+       if (err)
+               return err;
 
        if (map_events != expected_events) {
                pr_err("testing event table: found %d, but expected %d\n",
                       map_events, expected_events);
-               return -1;
+               return TEST_FAIL;
        }
 
        return 0;
index 8d99453..cae97b6 100644 (file)
@@ -538,12 +538,40 @@ static int metricgroup__print_sys_event_iter(const struct pmu_event *pe,
                                     d->details, d->groups, d->metriclist);
 }
 
+struct metricgroup_print_data {
+       const char *pmu_name;
+       struct strlist *metriclist;
+       char *filter;
+       struct rblist *groups;
+       bool metricgroups;
+       bool raw;
+       bool details;
+};
+
+static int metricgroup__print_callback(const struct pmu_event *pe,
+                                      const struct pmu_event *table __maybe_unused,
+                                      void *vdata)
+{
+       struct metricgroup_print_data *data = vdata;
+
+       if (!pe->metric_expr)
+               return 0;
+
+       if (data->pmu_name && perf_pmu__is_hybrid(pe->pmu) && strcmp(data->pmu_name, pe->pmu))
+               return 0;
+
+       return metricgroup__print_pmu_event(pe, data->metricgroups, data->filter,
+                                           data->raw, data->details, data->groups,
+                                           data->metriclist);
+}
+
 void metricgroup__print(bool metrics, bool metricgroups, char *filter,
                        bool raw, bool details, const char *pmu_name)
 {
        struct rblist groups;
        struct rb_node *node, *next;
        struct strlist *metriclist = NULL;
+       const struct pmu_event *table;
 
        if (!metricgroups) {
                metriclist = strlist__new(NULL, NULL);
@@ -555,22 +583,22 @@ void metricgroup__print(bool metrics, bool metricgroups, char *filter,
        groups.node_new = mep_new;
        groups.node_cmp = mep_cmp;
        groups.node_delete = mep_delete;
-       for (const struct pmu_event *pe = pmu_events_table__find(); pe; pe++) {
+       table = pmu_events_table__find();
+       if (table) {
+               struct metricgroup_print_data data = {
+                       .pmu_name = pmu_name,
+                       .metriclist = metriclist,
+                       .metricgroups = metricgroups,
+                       .filter = filter,
+                       .raw = raw,
+                       .details = details,
+                       .groups = &groups,
+               };
 
-               if (!pe->name && !pe->metric_group && !pe->metric_name)
-                       break;
-               if (!pe->metric_expr)
-                       continue;
-               if (pmu_name && perf_pmu__is_hybrid(pe->pmu) &&
-                   strcmp(pmu_name, pe->pmu)) {
-                       continue;
-               }
-               if (metricgroup__print_pmu_event(pe, metricgroups, filter,
-                                                raw, details, &groups,
-                                                metriclist) < 0)
-                       return;
+               pmu_events_table_for_each_event(table,
+                                               metricgroup__print_callback,
+                                               &data);
        }
-
        {
                struct metricgroup_iter_data data = {
                        .fn = metricgroup__print_sys_event_iter,
@@ -1043,30 +1071,35 @@ static int __add_metric(struct list_head *metric_list,
        return ret;
 }
 
-#define table_for_each_event(__pe, __idx, __table)                                     \
-       if (__table)                                                            \
-               for (__idx = 0, __pe = &__table[__idx];                         \
-                    __pe->name || __pe->metric_group || __pe->metric_name;     \
-                    __pe = &__table[++__idx])
+struct metricgroup__find_metric_data {
+       const char *metric;
+       const struct pmu_event *pe;
+};
+
+static int metricgroup__find_metric_callback(const struct pmu_event *pe,
+                                            const struct pmu_event *table  __maybe_unused,
+                                            void *vdata)
+{
+       struct metricgroup__find_metric_data *data = vdata;
+
+       if (!match_metric(pe->metric_name, data->metric))
+               return 0;
 
-#define table_for_each_metric(__pe, __idx, __table, __metric)          \
-       table_for_each_event(__pe, __idx, __table)                              \
-               if (__pe->metric_expr &&                                \
-                   (match_metric(__pe->metric_group, __metric) ||      \
-                    match_metric(__pe->metric_name, __metric)))
+       data->pe = pe;
+       return -1;
+}
 
 const struct pmu_event *metricgroup__find_metric(const char *metric,
                                                 const struct pmu_event *table)
 {
-       const struct pmu_event *pe;
-       int i;
+       struct metricgroup__find_metric_data data = {
+               .metric = metric,
+               .pe = NULL,
+       };
 
-       table_for_each_event(pe, i, table) {
-               if (match_metric(pe->metric_name, metric))
-                       return pe;
-       }
+       pmu_events_table_for_each_event(table, metricgroup__find_metric_callback, &data);
 
-       return NULL;
+       return data.pe;
 }
 
 static int add_metric(struct list_head *metric_list,
@@ -1151,6 +1184,33 @@ static int metric_list_cmp(void *priv __maybe_unused, const struct list_head *l,
        return right_count - left_count;
 }
 
+struct metricgroup__add_metric_data {
+       struct list_head *list;
+       const char *metric_name;
+       const char *modifier;
+       bool metric_no_group;
+       bool has_match;
+};
+
+static int metricgroup__add_metric_callback(const struct pmu_event *pe,
+                                           const struct pmu_event *table,
+                                           void *vdata)
+{
+       struct metricgroup__add_metric_data *data = vdata;
+       int ret = 0;
+
+       if (pe->metric_expr &&
+               (match_metric(pe->metric_group, data->metric_name) ||
+                match_metric(pe->metric_name, data->metric_name))) {
+
+               data->has_match = true;
+               ret = add_metric(data->list, pe, data->modifier, data->metric_no_group,
+                                /*root_metric=*/NULL,
+                                /*visited_metrics=*/NULL, table);
+       }
+       return ret;
+}
+
 /**
  * metricgroup__add_metric - Find and add a metric, or a metric group.
  * @metric_name: The name of the metric or metric group. For example, "IPC"
@@ -1169,24 +1229,29 @@ static int metricgroup__add_metric(const char *metric_name, const char *modifier
                                   struct list_head *metric_list,
                                   const struct pmu_event *table)
 {
-       const struct pmu_event *pe;
        LIST_HEAD(list);
-       int i, ret;
+       int ret;
        bool has_match = false;
 
-       /*
-        * Iterate over all metrics seeing if metric matches either the name or
-        * group. When it does add the metric to the list.
-        */
-       table_for_each_metric(pe, i, table, metric_name) {
-               has_match = true;
-               ret = add_metric(&list, pe, modifier, metric_no_group,
-                                /*root_metric=*/NULL,
-                                /*visited_metrics=*/NULL, table);
+       {
+               struct metricgroup__add_metric_data data = {
+                       .list = &list,
+                       .metric_name = metric_name,
+                       .modifier = modifier,
+                       .metric_no_group = metric_no_group,
+                       .has_match = false,
+               };
+               /*
+                * Iterate over all metrics seeing if metric matches either the
+                * name or group. When it does add the metric to the list.
+                */
+               ret = pmu_events_table_for_each_event(table, metricgroup__add_metric_callback,
+                                                     &data);
                if (ret)
                        goto out;
-       }
 
+               has_match = data.has_match;
+       }
        {
                struct metricgroup_iter_data data = {
                        .fn = metricgroup__add_metric_sys_event_iter,
@@ -1602,26 +1667,30 @@ int metricgroup__parse_groups_test(struct evlist *evlist,
                            metric_no_merge, &perf_pmu__fake, metric_events, table);
 }
 
+static int metricgroup__has_metric_callback(const struct pmu_event *pe,
+                                           const struct pmu_event *table __maybe_unused,
+                                           void *vdata)
+{
+       const char *metric = vdata;
+
+       if (!pe->metric_expr)
+               return 0;
+
+       if (match_metric(pe->metric_name, metric))
+               return 1;
+
+       return 0;
+}
+
 bool metricgroup__has_metric(const char *metric)
 {
        const struct pmu_event *table = pmu_events_table__find();
-       const struct pmu_event *pe;
-       int i;
 
        if (!table)
                return false;
 
-       for (i = 0; ; i++) {
-               pe = &table[i];
-
-               if (!pe->name && !pe->metric_group && !pe->metric_name)
-                       break;
-               if (!pe->metric_expr)
-                       continue;
-               if (match_metric(pe->metric_name, metric))
-                       return true;
-       }
-       return false;
+       return pmu_events_table_for_each_event(table, metricgroup__has_metric_callback,
+                                              (void *)metric) ? true : false;
 }
 
 int metricgroup__copy_metric_events(struct evlist *evlist, struct cgroup *cgrp,
index f117324..dd1e171 100644 (file)
@@ -791,6 +791,36 @@ out:
        return res;
 }
 
+struct pmu_add_cpu_aliases_map_data {
+       struct list_head *head;
+       const char *name;
+       const char *cpu_name;
+       struct perf_pmu *pmu;
+};
+
+static int pmu_add_cpu_aliases_map_callback(const struct pmu_event *pe,
+                                       const struct pmu_event *table __maybe_unused,
+                                       void *vdata)
+{
+       struct pmu_add_cpu_aliases_map_data *data = vdata;
+       const char *pname = pe->pmu ? pe->pmu : data->cpu_name;
+
+       if (!pe->name)
+               return 0;
+
+       if (data->pmu->is_uncore && pmu_uncore_alias_match(pname, data->name))
+               goto new_alias;
+
+       if (strcmp(pname, data->name))
+               return 0;
+
+new_alias:
+       /* need type casts to override 'const' */
+       __perf_pmu__new_alias(data->head, NULL, (char *)pe->name, (char *)pe->desc,
+                             (char *)pe->event, pe);
+       return 0;
+}
+
 /*
  * From the pmu_events_map, find the table of PMU events that corresponds
  * to the current running CPU. Then, add all PMU events from that table
@@ -799,35 +829,14 @@ out:
 void pmu_add_cpu_aliases_table(struct list_head *head, struct perf_pmu *pmu,
                               const struct pmu_event *table)
 {
-       int i;
-       const char *name = pmu->name;
-       /*
-        * Found a matching PMU events table. Create aliases
-        */
-       i = 0;
-       while (1) {
-               const char *cpu_name = is_arm_pmu_core(name) ? name : "cpu";
-               const struct pmu_event *pe = &table[i++];
-               const char *pname = pe->pmu ? pe->pmu : cpu_name;
-
-               if (!pe->name) {
-                       if (pe->metric_group || pe->metric_name)
-                               continue;
-                       break;
-               }
-
-               if (pmu->is_uncore && pmu_uncore_alias_match(pname, name))
-                       goto new_alias;
-
-               if (strcmp(pname, name))
-                       continue;
+       struct pmu_add_cpu_aliases_map_data data = {
+               .head = head,
+               .name = pmu->name,
+               .cpu_name = is_arm_pmu_core(pmu->name) ? pmu->name : "cpu",
+               .pmu = pmu,
+       };
 
-new_alias:
-               /* need type casts to override 'const' */
-               __perf_pmu__new_alias(head, NULL, (char *)pe->name,
-                               (char *)pe->desc, (char *)pe->event,
-                               pe);
-       }
+       pmu_events_table_for_each_event(table, pmu_add_cpu_aliases_map_callback, &data);
 }
 
 static void pmu_add_cpu_aliases(struct list_head *head, struct perf_pmu *pmu)
index dddd2be..235319d 100644 (file)
@@ -129,6 +129,28 @@ static int get_counterset_start(int setnr)
        }
 }
 
+struct get_counter_name_data {
+       int wanted;
+       const char *result;
+};
+
+static int get_counter_name_callback(const struct pmu_event *evp,
+                                    const struct pmu_event *table __maybe_unused,
+                                    void *vdata)
+{
+       struct get_counter_name_data *data = vdata;
+       int rc, event_nr;
+
+       if (evp->name == NULL || evp->event == NULL)
+               return 0;
+       rc = sscanf(evp->event, "event=%x", &event_nr);
+       if (rc == 1 && event_nr == data->wanted) {
+               data->result = evp->name;
+               return 1; /* Terminate the search. */
+       }
+       return 0;
+}
+
 /* Scan the PMU table and extract the logical name of a counter from the
  * PMU events table. Input is the counter set and counter number with in the
  * set. Construct the event number and use this as key. If they match return
@@ -137,20 +159,16 @@ static int get_counterset_start(int setnr)
  */
 static const char *get_counter_name(int set, int nr, const struct pmu_event *table)
 {
-       int rc, event_nr, wanted = get_counterset_start(set) + nr;
+       struct get_counter_name_data data = {
+               .wanted = get_counterset_start(set) + nr,
+               .result = NULL,
+       };
 
-       if (table) {
-               const struct pmu_event *evp = table;
+       if (!table)
+               return NULL;
 
-               for (; evp->name || evp->event || evp->desc; ++evp) {
-                       if (evp->name == NULL || evp->event == NULL)
-                               continue;
-                       rc = sscanf(evp->event, "event=%x", &event_nr);
-                       if (rc == 1 && event_nr == wanted)
-                               return evp->name;
-               }
-       }
-       return NULL;
+       pmu_events_table_for_each_event(table, get_counter_name_callback, &data);
+       return data.result;
 }
 
 static void s390_cpumcfdg_dump(struct perf_sample *sample)