@@ -210,7 +210,8 @@ static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
 }
 
 static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
-				 char *desc, char *val, char *long_desc)
+				 char *desc, char *val, char *long_desc,
+				 char *topic)
 {
 	struct perf_pmu_alias *alias;
 	int ret;

@@ -245,6 +246,7 @@ static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
 	alias->desc = desc ? strdup(desc) : NULL;
 	alias->long_desc = long_desc ? strdup(long_desc) :
 				desc ? strdup(desc) : NULL;
+	alias->topic = topic ? strdup(topic) : NULL;
 
 	list_add_tail(&alias->list, list);
 

@@ -262,7 +264,7 @@ 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);
+	return __perf_pmu__new_alias(list, dir, name, NULL, buf, NULL, NULL);
 }
 
 static inline bool pmu_alias_info_file(char *name)

@@ -511,7 +513,7 @@ static int pmu_add_cpu_aliases(struct list_head *head)
 		/* need type casts to override 'const' */
 		__perf_pmu__new_alias(head, NULL, (char *)pe->name,
 				(char *)pe->desc, (char *)pe->event,
-				(char *)pe->long_desc);
+				(char *)pe->long_desc, (char *)pe->topic);
 	}
 
 out:

@@ -1042,19 +1044,26 @@ static char *format_alias_or(char *buf, int len, struct perf_pmu *pmu,
 	return buf;
 }
 
-struct pair {
+struct sevent {
 	char *name;
 	char *desc;
+	char *topic;
 };
 
-static int cmp_pair(const void *a, const void *b)
+static int cmp_sevent(const void *a, const void *b)
 {
-	const struct pair *as = a;
-	const struct pair *bs = b;
+	const struct sevent *as = a;
+	const struct sevent *bs = b;
 
 	/* Put extra events last */
 	if (!!as->desc != !!bs->desc)
 		return !!as->desc - !!bs->desc;
+	if (as->topic && bs->topic) {
+		int n = strcmp(as->topic, bs->topic);
+
+		if (n)
+			return n;
+	}
 	return strcmp(as->name, bs->name);
 }
 

@@ -1088,9 +1097,10 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
 	char buf[1024];
 	int printed = 0;
 	int len, j;
-	struct pair *aliases;
+	struct sevent *aliases;
 	int numdesc = 0;
 	int columns = pager_get_columns();
+	char *topic = NULL;
 
 	pmu = NULL;
 	len = 0;

@@ -1100,7 +1110,7 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
 		if (pmu->selectable)
 			len++;
 	}
-	aliases = zalloc(sizeof(struct pair) * len);
+	aliases = zalloc(sizeof(struct sevent) * len);
 	if (!aliases)
 		goto out_enomem;
 	pmu = NULL;

@@ -1130,6 +1140,7 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
 
 			aliases[j].desc = long_desc ? alias->long_desc :
 						alias->desc;
+			aliases[j].topic = alias->topic;
 			j++;
 		}
 		if (pmu->selectable) {

@@ -1141,7 +1152,7 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
 		}
 	}
 	len = j;
-	qsort(aliases, len, sizeof(struct pair), cmp_pair);
+	qsort(aliases, len, sizeof(struct sevent), cmp_sevent);
 	for (j = 0; j < len; j++) {
 		if (name_only) {
 			printf("%s ", aliases[j].name);

@@ -1150,6 +1161,12 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
 		if (aliases[j].desc && !quiet_flag) {
 			if (numdesc++ == 0)
 				printf("\n");
+			if (aliases[j].topic && (!topic ||
+					strcmp(topic, aliases[j].topic))) {
+				printf("%s%s:\n", topic ? "\n" : "",
+						aliases[j].topic);
+				topic = aliases[j].topic;
+			}
 			printf("  %-50s\n", aliases[j].name);
 			printf("%*s", 8, "[");
 			wordwrap(aliases[j].desc, 8, columns, 0);

@@ -40,6 +40,7 @@ struct perf_pmu_alias {
 	char *name;
 	char *desc;
 	char *long_desc;
+	char *topic;
 	struct list_head terms; /* HEAD struct parse_events_term -> list */
 	struct list_head list;  /* ELEM */
 	char unit[UNIT_MAX_LEN+1];