perf pmu: Add support for MetricName JSON attribute

Add support for a new JSON event attribute to name MetricExpr for better
output in perf stat.

If the event has no MetricName it uses the normal event name instead to
describe the metric.

Before

  % perf stat -a -I 1000 -e '{unc_p_clockticks,unc_p_freq_max_os_cycles}' --metric-only
           time unc_p_freq_max_os_cycles
     1.000149775     15.7
     2.000344807     19.3
     3.000502544     16.7
     4.000640656      6.6
     5.000779955      9.9

After

  % perf stat -a -I 1000 -e '{unc_p_clockticks,unc_p_freq_max_os_cycles}' --metric-only
           time freq_max_os_cycles %
     1.000149775     15.7
     2.000344807     19.3
     3.000502544     16.7
     4.000640656      6.6
     5.000779955      9.9

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170320201711.14142-13-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index f819ad162b7c..bcf752fa345b 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -232,7 +232,8 @@ static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
 				 char *desc, char *val,
 				 char *long_desc, char *topic,
 				 char *unit, char *perpkg,
-				 char *metric_expr)
+				 char *metric_expr,
+				 char *metric_name)
 {
 	struct perf_pmu_alias *alias;
 	int ret;
@@ -267,6 +268,7 @@ static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
 	}
 
 	alias->metric_expr = metric_expr ? strdup(metric_expr) : NULL;
+	alias->metric_name = metric_name ? strdup(metric_name): NULL;
 	alias->desc = desc ? strdup(desc) : NULL;
 	alias->long_desc = long_desc ? strdup(long_desc) :
 				desc ? strdup(desc) : NULL;
@@ -296,7 +298,7 @@ static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FI
 	buf[ret] = 0;
 
 	return __perf_pmu__new_alias(list, dir, name, NULL, buf, NULL, NULL, NULL,
-				     NULL, NULL);
+				     NULL, NULL, NULL);
 }
 
 static inline bool pmu_alias_info_file(char *name)
@@ -567,7 +569,8 @@ static void pmu_add_cpu_aliases(struct list_head *head, const char *name)
 				(char *)pe->desc, (char *)pe->event,
 				(char *)pe->long_desc, (char *)pe->topic,
 				(char *)pe->unit, (char *)pe->perpkg,
-				(char *)pe->metric_expr);
+				(char *)pe->metric_expr,
+				(char *)pe->metric_name);
 	}
 
 out:
@@ -995,6 +998,7 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
 	info->scale    = 0.0;
 	info->snapshot = false;
 	info->metric_expr = NULL;
+	info->metric_name = NULL;
 
 	list_for_each_entry_safe(term, h, head_terms, list) {
 		alias = pmu_find_alias(pmu, term);
@@ -1011,6 +1015,7 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
 		if (alias->per_pkg)
 			info->per_pkg = true;
 		info->metric_expr = alias->metric_expr;
+		info->metric_name = alias->metric_name;
 
 		list_del(&term->list);
 		free(term);
@@ -1106,6 +1111,7 @@ struct sevent {
 	char *str;
 	char *pmu;
 	char *metric_expr;
+	char *metric_name;
 };
 
 static int cmp_sevent(const void *a, const void *b)
@@ -1205,6 +1211,7 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
 			aliases[j].str = alias->str;
 			aliases[j].pmu = pmu->name;
 			aliases[j].metric_expr = alias->metric_expr;
+			aliases[j].metric_name = alias->metric_name;
 			j++;
 		}
 		if (pmu->selectable &&
@@ -1241,6 +1248,8 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
 			printf("]\n");
 			if (verbose > 0) {
 				printf("%*s%s/%s/ ", 8, "", aliases[j].pmu, aliases[j].str);
+				if (aliases[j].metric_name)
+					printf(" MetricName: %s", aliases[j].metric_name);
 				if (aliases[j].metric_expr)
 					printf(" MetricExpr: %s", aliases[j].metric_expr);
 				putchar('\n');