[PATCH v2 02/18] perf pmu: Abstract alias/event struct

[Ian Rogers <irogers@google.com>]

In order to be able to lazily compute aliases/events for a PMU, move
the struct perf_pmu_alias into pmu.c. Add perf_pmu__find_event and
perf_pmu__for_each_event that take a callback that is called for the
found event or for each event. The layout of struct pmu and the
event/alias list is unchanged but the API is altered so that aliases
are no longer directly accessed, allowing for later changes.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/bench/pmu-scan.c    |   8 +-
 tools/perf/tests/pmu-events.c  | 101 +++++++--------
 tools/perf/util/parse-events.c |  67 ++++------
 tools/perf/util/pmu.c          | 212 +++++++++++++++++++++++++++---
 tools/perf/util/pmu.h          |  71 +++-------
 tools/perf/util/pmus.c         | 230 +++++++++++----------------------
 6 files changed, 366 insertions(+), 323 deletions(-)

diff --git a/tools/perf/bench/pmu-scan.c b/tools/perf/bench/pmu-scan.c
index c7d207f8e13c..9e4d36486f62 100644
--- a/tools/perf/bench/pmu-scan.c
+++ b/tools/perf/bench/pmu-scan.c
@@ -57,9 +57,7 @@ static int save_result(void)
 		r->is_core = pmu->is_core;
 		r->nr_caps = pmu->nr_caps;
 
-		r->nr_aliases = 0;
-		list_for_each(list, &pmu->aliases)
-			r->nr_aliases++;
+		r->nr_aliases = perf_pmu__num_events(pmu);
 
 		r->nr_formats = 0;
 		list_for_each(list, &pmu->format)
@@ -98,9 +96,7 @@ static int check_result(bool core_only)
 			return -1;
 		}
 
-		nr = 0;
-		list_for_each(list, &pmu->aliases)
-			nr++;
+		nr = perf_pmu__num_events(pmu);
 		if (nr != r->nr_aliases) {
 			pr_err("Unmatched number of event aliases in %s: expect %d vs got %d\n",
 				pmu->name, r->nr_aliases, nr);
diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
index 05d6e6e21c6f..dc87e66fb118 100644
--- a/tools/perf/tests/pmu-events.c
+++ b/tools/perf/tests/pmu-events.c
@@ -341,7 +341,7 @@ static int compare_pmu_events(const struct pmu_event *e1, const struct pmu_event
 	return 0;
 }
 
-static int compare_alias_to_test_event(struct perf_pmu_alias *alias,
+static int compare_alias_to_test_event(struct pmu_event_info *alias,
 				struct perf_pmu_test_event const *test_event,
 				char const *pmu_name)
 {
@@ -496,6 +496,23 @@ static int test__pmu_event_table(struct test_suite *test __maybe_unused,
 	return 0;
 }
 
+struct test_core_pmu_event_aliases_cb_args {
+	struct perf_pmu_test_event const *test_event;
+	int *count;
+};
+
+static int test_core_pmu_event_aliases_cb(void *state, struct pmu_event_info *alias)
+{
+	struct test_core_pmu_event_aliases_cb_args *args = state;
+
+	if (compare_alias_to_test_event(alias, args->test_event, alias->pmu->name))
+		return -1;
+	(*args->count)++;
+	pr_debug2("testing aliases core PMU %s: matched event %s\n",
+		alias->pmu_name, alias->name);
+	return 0;
+}
+
 /* Verify aliases are as expected */
 static int __test_core_pmu_event_aliases(char *pmu_name, int *count)
 {
@@ -522,25 +539,19 @@ static int __test_core_pmu_event_aliases(char *pmu_name, int *count)
 	pmu_add_cpu_aliases_table(pmu, table);
 
 	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;
-		struct perf_pmu_alias *alias = perf_pmu__find_alias(pmu, event->name);
-
-		if (!alias) {
-			pr_debug("testing aliases core PMU %s: no alias, alias_table->name=%s\n",
-				  pmu_name, event->name);
-			res = -1;
-			break;
-		}
-
-		if (compare_alias_to_test_event(alias, test_event, pmu_name)) {
-			res = -1;
-			break;
-		}
-
-		(*count)++;
-		pr_debug2("testing aliases core PMU %s: matched event %s\n",
-			  pmu_name, alias->name);
+		struct perf_pmu_test_event test_event = **test_event_table;
+		struct pmu_event const *event = &test_event.event;
+		struct test_core_pmu_event_aliases_cb_args args = {
+			.test_event = &test_event,
+			.count = count,
+		};
+		int err;
+
+		test_event.event.pmu = pmu_name;
+		err = perf_pmu__find_event(pmu, event->name, &args,
+					   test_core_pmu_event_aliases_cb);
+		if (err)
+			res = err;
 	}
 	perf_pmu__delete(pmu);
 
@@ -553,7 +564,6 @@ static int __test_uncore_pmu_event_aliases(struct perf_pmu_test_pmu *test_pmu)
 	struct perf_pmu_test_event const **table;
 	struct perf_pmu *pmu = &test_pmu->pmu;
 	const char *pmu_name = pmu->name;
-	struct perf_pmu_alias *a, *tmp, *alias;
 	const struct pmu_events_table *events_table;
 	int res = 0;
 
@@ -564,8 +574,7 @@ static int __test_uncore_pmu_event_aliases(struct perf_pmu_test_pmu *test_pmu)
 	pmu_add_sys_aliases(pmu);
 
 	/* Count how many aliases we generated */
-	list_for_each_entry(alias, &pmu->aliases, list)
-		alias_count++;
+	alias_count = perf_pmu__num_events(pmu);
 
 	/* Count how many aliases we expect from the known table */
 	for (table = &test_pmu->aliases[0]; *table; table++)
@@ -574,33 +583,25 @@ static int __test_uncore_pmu_event_aliases(struct perf_pmu_test_pmu *test_pmu)
 	if (alias_count != to_match_count) {
 		pr_debug("testing aliases uncore PMU %s: mismatch expected aliases (%d) vs found (%d)\n",
 			 pmu_name, to_match_count, alias_count);
-		res = -1;
-		goto out;
+		return -1;
 	}
 
-	list_for_each_entry(alias, &pmu->aliases, list) {
-		bool matched = false;
-
-		for (table = &test_pmu->aliases[0]; *table; table++) {
-			struct perf_pmu_test_event const *test_event = *table;
-			struct pmu_event const *event = &test_event->event;
-
-			if (!strcmp(event->name, alias->name)) {
-				if (compare_alias_to_test_event(alias,
-							test_event,
-							pmu_name)) {
-					continue;
-				}
-				matched = true;
-				matched_count++;
-			}
-		}
-
-		if (matched == false) {
+	for (table = &test_pmu->aliases[0]; *table; table++) {
+		struct perf_pmu_test_event test_event = **table;
+		struct pmu_event const *event = &test_event.event;
+		int err;
+		struct test_core_pmu_event_aliases_cb_args args = {
+			.test_event = &test_event,
+			.count = &matched_count,
+		};
+
+		err = perf_pmu__find_event(pmu, event->name, &args,
+					   test_core_pmu_event_aliases_cb);
+		if (err) {
+			res = err;
 			pr_debug("testing aliases uncore PMU %s: could not match alias %s\n",
-				 pmu_name, alias->name);
-			res = -1;
-			goto out;
+				 pmu_name, event->name);
+			return -1;
 		}
 	}
 
@@ -609,12 +610,6 @@ static int __test_uncore_pmu_event_aliases(struct perf_pmu_test_pmu *test_pmu)
 			 pmu_name, matched_count, alias_count);
 		res = -1;
 	}
-
-out:
-	list_for_each_entry_safe(a, tmp, &pmu->aliases, list) {
-		list_del(&a->list);
-		perf_pmu_free_alias(a);
-	}
 	return res;
 }
 
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 7d9d687d9191..7cad82a9f578 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -193,38 +193,31 @@ static void fix_raw(struct list_head *config_terms, struct perf_pmu *pmu)
 	struct parse_events_term *term;
 
 	list_for_each_entry(term, config_terms, list) {
-		struct perf_pmu_alias *alias;
-		bool matched = false;
+		u64 num;
 
 		if (term->type_term != PARSE_EVENTS__TERM_TYPE_RAW)
 			continue;
 
-		list_for_each_entry(alias, &pmu->aliases, list) {
-			if (!strcmp(alias->name, term->val.str)) {
-				free(term->config);
-				term->config = term->val.str;
-				term->type_val = PARSE_EVENTS__TERM_TYPE_NUM;
-				term->type_term = PARSE_EVENTS__TERM_TYPE_USER;
-				term->val.num = 1;
-				term->no_value = true;
-				matched = true;
-				break;
-			}
-		}
-		if (!matched) {
-			u64 num;
-
+		if (perf_pmu__have_event(pmu, term->val.str)) {
 			free(term->config);
-			term->config = strdup("config");
-			errno = 0;
-			num = strtoull(term->val.str + 1, NULL, 16);
-			assert(errno == 0);
-			free(term->val.str);
+			term->config = term->val.str;
 			term->type_val = PARSE_EVENTS__TERM_TYPE_NUM;
-			term->type_term = PARSE_EVENTS__TERM_TYPE_CONFIG;
-			term->val.num = num;
-			term->no_value = false;
+			term->type_term = PARSE_EVENTS__TERM_TYPE_USER;
+			term->val.num = 1;
+			term->no_value = true;
+			continue;
 		}
+
+		free(term->config);
+		term->config = strdup("config");
+		errno = 0;
+		num = strtoull(term->val.str + 1, NULL, 16);
+		assert(errno == 0);
+		free(term->val.str);
+		term->type_val = PARSE_EVENTS__TERM_TYPE_NUM;
+		term->type_term = PARSE_EVENTS__TERM_TYPE_CONFIG;
+		term->val.num = num;
+		term->no_value = false;
 	}
 }
 
@@ -1458,28 +1451,22 @@ int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
 	INIT_LIST_HEAD(list);
 
 	while ((pmu = perf_pmus__scan(pmu)) != NULL) {
-		struct perf_pmu_alias *alias;
 		bool auto_merge_stats;
 
 		if (parse_events__filter_pmu(parse_state, pmu))
 			continue;
 
-		auto_merge_stats = perf_pmu__auto_merge_stats(pmu);
+		if (!perf_pmu__have_event(pmu, str))
+			continue;
 
-		list_for_each_entry(alias, &pmu->aliases, list) {
-			if (!strcasecmp(alias->name, str)) {
-				parse_events_copy_term_list(head, &orig_head);
-				if (!parse_events_add_pmu(parse_state, list,
-							  pmu->name, orig_head,
-							  auto_merge_stats, loc)) {
-					pr_debug("%s -> %s/%s/\n", str,
-						 pmu->name, alias->str);
-					parse_state->wild_card_pmus = true;
-					ok++;
-				}
-				parse_events_terms__delete(orig_head);
-			}
+		auto_merge_stats = perf_pmu__auto_merge_stats(pmu);
+		parse_events_copy_term_list(head, &orig_head);
+		if (!parse_events_add_pmu(parse_state, list, pmu->name,
+					  orig_head, auto_merge_stats, loc)) {
+			pr_debug("%s -> %s/%s/\n", str, pmu->name, str);
+			ok++;
 		}
+		parse_events_terms__delete(orig_head);
 	}
 
 	if (parse_state->fake_pmu) {
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 3cfd3e58da23..268aaebfa70c 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -31,6 +31,61 @@
 
 struct perf_pmu perf_pmu__fake;
 
+#define UNIT_MAX_LEN	31 /* max length for event unit name */
+
+/**
+ * struct perf_pmu_alias - An event either read from sysfs or builtin in
+ * pmu-events.c, created by parsing the pmu-events json files.
+ */
+struct perf_pmu_alias {
+	/** @name: Name of the event like "mem-loads". */
+	char *name;
+	/** @desc: Optional short description of the event. */
+	char *desc;
+	/** @long_desc: Optional long description. */
+	char *long_desc;
+	/**
+	 * @topic: Optional topic such as cache or pipeline, particularly for
+	 * json events.
+	 */
+	char *topic;
+	/**
+	 * @str: Comma separated parameter list like
+	 * "event=0xcd,umask=0x1,ldlat=0x3".
+	 */
+	char *str;
+	/** @terms: Owned list of the original parsed parameters. */
+	struct list_head terms;
+	/** @list: List element of struct perf_pmu aliases. */
+	struct list_head list;
+	/** @unit: Units for the event, such as bytes or cache lines. */
+	char unit[UNIT_MAX_LEN+1];
+	/** @scale: Value to scale read counter values by. */
+	double scale;
+	/**
+	 * @per_pkg: Does the file
+	 * <sysfs>/bus/event_source/devices/<pmu_name>/events/<name>.per-pkg or
+	 * equivalent json value exist and have the value 1.
+	 */
+	bool per_pkg;
+	/**
+	 * @snapshot: Does the file
+	 * <sysfs>/bus/event_source/devices/<pmu_name>/events/<name>.snapshot
+	 * exist and have the value 1.
+	 */
+	bool snapshot;
+	/**
+	 * @deprecated: Is the event hidden and so not shown in perf list by
+	 * default.
+	 */
+	bool deprecated;
+	/**
+	 * @pmu_name: The name copied from the json struct pmu_event. This can
+	 * differ from the PMU name as it won't have suffixes.
+	 */
+	char *pmu_name;
+};
+
 /**
  * struct perf_pmu_format - Values from a format file read from
  * <sysfs>/devices/cpu/format/ held in struct perf_pmu.
@@ -355,7 +410,7 @@ static void perf_pmu_update_alias(struct perf_pmu_alias *old,
 }
 
 /* Delete an alias entry. */
-void perf_pmu_free_alias(struct perf_pmu_alias *newalias)
+static void perf_pmu_free_alias(struct perf_pmu_alias *newalias)
 {
 	zfree(&newalias->name);
 	zfree(&newalias->desc);
@@ -1349,10 +1404,20 @@ int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
 	return perf_pmu__config_terms(pmu, attr, head_terms, zero, err);
 }
 
+static struct perf_pmu_alias *perf_pmu__find_alias(const struct perf_pmu *pmu, const char *str)
+{
+	struct perf_pmu_alias *alias;
+
+	list_for_each_entry(alias, &pmu->aliases, list) {
+		if (!strcasecmp(alias->name, str))
+			return alias;
+	}
+	return NULL;
+}
+
 static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
 					     struct parse_events_term *term)
 {
-	struct perf_pmu_alias *alias;
 	char *name;
 
 	if (parse_events__is_hardcoded_term(term))
@@ -1364,6 +1429,7 @@ static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
 		if (pmu_find_format(&pmu->format, term->config))
 			return NULL;
 		name = term->config;
+
 	} else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
 		if (strcasecmp(term->config, "event"))
 			return NULL;
@@ -1372,11 +1438,7 @@ static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
 		return NULL;
 	}
 
-	list_for_each_entry(alias, &pmu->aliases, list) {
-		if (!strcasecmp(alias->name, name))
-			return alias;
-	}
-	return NULL;
+	return perf_pmu__find_alias(pmu, name);
 }
 
 
@@ -1459,16 +1521,33 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
 	return 0;
 }
 
-struct perf_pmu_alias *perf_pmu__find_alias(struct perf_pmu *pmu, const char *event)
+struct find_event_args {
+	const char *event;
+	void *state;
+	pmu_event_callback cb;
+};
+
+static int find_event_callback(void *state, struct pmu_event_info *info)
 {
-	struct perf_pmu_alias *alias;
+	struct find_event_args *args = state;
 
-	list_for_each_entry(alias, &pmu->aliases, list)
-		if (!strcmp(event, alias->name))
-			return alias;
+	if (!strcmp(args->event, info->name))
+		return args->cb(args->state, info);
 
-	return NULL;
+	return 0;
 }
+
+int perf_pmu__find_event(struct perf_pmu *pmu, const char *event, void *state, pmu_event_callback cb)
+{
+	struct find_event_args args = {
+		.event = event,
+		.state = state,
+		.cb = cb,
+	};
+
+	return perf_pmu__for_each_event(pmu, &args, find_event_callback);
+}
+
 static void perf_pmu__del_formats(struct list_head *formats)
 {
 	struct perf_pmu_format *fmt, *tmp;
@@ -1508,13 +1587,110 @@ bool perf_pmu__auto_merge_stats(const struct perf_pmu *pmu)
 
 bool perf_pmu__have_event(const struct perf_pmu *pmu, const char *name)
 {
-	struct perf_pmu_alias *alias;
+	return perf_pmu__find_alias(pmu, name) != NULL;
+}
 
-	list_for_each_entry(alias, &pmu->aliases, list) {
-		if (!strcmp(alias->name, name))
-			return true;
+size_t perf_pmu__num_events(const struct perf_pmu *pmu)
+{
+	struct list_head *list;
+	size_t nr = 0;
+
+	list_for_each(list, &pmu->aliases)
+		nr++;
+
+	return pmu->selectable ? nr + 1 : nr;
+}
+
+static int sub_non_neg(int a, int b)
+{
+	if (b > a)
+		return 0;
+	return a - b;
+}
+
+static char *format_alias(char *buf, int len, const struct perf_pmu *pmu,
+			  const struct perf_pmu_alias *alias)
+{
+	struct parse_events_term *term;
+	int used = snprintf(buf, len, "%s/%s", pmu->name, alias->name);
+
+	list_for_each_entry(term, &alias->terms, list) {
+		if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
+			used += snprintf(buf + used, sub_non_neg(len, used),
+					",%s=%s", term->config,
+					term->val.str);
 	}
-	return false;
+
+	if (sub_non_neg(len, used) > 0) {
+		buf[used] = '/';
+		used++;
+	}
+	if (sub_non_neg(len, used) > 0) {
+		buf[used] = '\0';
+		used++;
+	} else
+		buf[len - 1] = '\0';
+
+	return buf;
+}
+
+int perf_pmu__for_each_event(const struct perf_pmu *pmu, void *state, pmu_event_callback cb)
+{
+	char buf[1024];
+	struct perf_pmu_alias *event;
+	struct pmu_event_info info = {
+		.pmu = pmu,
+	};
+	int ret = 0;
+
+	list_for_each_entry(event, &pmu->aliases, list) {
+		size_t buf_used;
+
+		info.pmu_name = event->pmu_name ?: pmu->name;
+		info.alias = NULL;
+		if (event->desc) {
+			info.name = event->name;
+			buf_used = 0;
+		} else {
+			info.name = format_alias(buf, sizeof(buf), pmu, event);
+			if (pmu->is_core) {
+				info.alias = info.name;
+				info.name = event->name;
+			}
+			buf_used = strlen(buf) + 1;
+		}
+		info.scale_unit = NULL;
+		if (strlen(event->unit) || event->scale != 1.0) {
+			info.scale_unit = buf + buf_used;
+			buf_used += snprintf(buf + buf_used, sizeof(buf) - buf_used,
+					"%G%s", event->scale, event->unit) + 1;
+		}
+		info.desc = event->desc;
+		info.long_desc = event->long_desc;
+		info.encoding_desc = buf + buf_used;
+		buf_used += snprintf(buf + buf_used, sizeof(buf) - buf_used,
+				"%s/%s/", info.pmu_name, event->str) + 1;
+		info.topic = event->topic;
+		info.str = event->str;
+		info.deprecated = event->deprecated;
+		ret = cb(state, &info);
+		if (ret)
+			return ret;
+	}
+	if (pmu->selectable) {
+		info.name = buf;
+		snprintf(buf, sizeof(buf), "%s//", pmu->name);
+		info.alias = NULL;
+		info.scale_unit = NULL;
+		info.desc = NULL;
+		info.long_desc = NULL;
+		info.encoding_desc = NULL;
+		info.topic = NULL;
+		info.pmu_name = pmu->name;
+		info.deprecated = false;
+		ret = cb(state, &info);
+	}
+	return ret;
 }
 
 bool perf_pmu__is_software(const struct perf_pmu *pmu)
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 675c9b97f7bf..f37e3d75094f 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -158,61 +158,22 @@ struct perf_pmu_info {
 	bool snapshot;
 };
 
-#define UNIT_MAX_LEN	31 /* max length for event unit name */
-
-/**
- * struct perf_pmu_alias - An event either read from sysfs or builtin in
- * pmu-events.c, created by parsing the pmu-events json files.
- */
-struct perf_pmu_alias {
-	/** @name: Name of the event like "mem-loads". */
-	char *name;
-	/** @desc: Optional short description of the event. */
-	char *desc;
-	/** @long_desc: Optional long description. */
-	char *long_desc;
-	/**
-	 * @topic: Optional topic such as cache or pipeline, particularly for
-	 * json events.
-	 */
-	char *topic;
-	/**
-	 * @str: Comma separated parameter list like
-	 * "event=0xcd,umask=0x1,ldlat=0x3".
-	 */
-	char *str;
-	/** @terms: Owned list of the original parsed parameters. */
-	struct list_head terms;
-	/** @list: List element of struct perf_pmu aliases. */
-	struct list_head list;
-	/** @unit: Units for the event, such as bytes or cache lines. */
-	char unit[UNIT_MAX_LEN+1];
-	/** @scale: Value to scale read counter values by. */
-	double scale;
-	/**
-	 * @per_pkg: Does the file
-	 * <sysfs>/bus/event_source/devices/<pmu_name>/events/<name>.per-pkg or
-	 * equivalent json value exist and have the value 1.
-	 */
-	bool per_pkg;
-	/**
-	 * @snapshot: Does the file
-	 * <sysfs>/bus/event_source/devices/<pmu_name>/events/<name>.snapshot
-	 * exist and have the value 1.
-	 */
-	bool snapshot;
-	/**
-	 * @deprecated: Is the event hidden and so not shown in perf list by
-	 * default.
-	 */
+struct pmu_event_info {
+	const struct perf_pmu *pmu;
+	const char *name;
+	const char* alias;
+	const char *scale_unit;
+	const char *desc;
+	const char *long_desc;
+	const char *encoding_desc;
+	const char *topic;
+	const char *pmu_name;
+	const char *str;
 	bool deprecated;
-	/**
-	 * @pmu_name: The name copied from the json struct pmu_event. This can
-	 * differ from the PMU name as it won't have suffixes.
-	 */
-	char *pmu_name;
 };
 
+typedef int (*pmu_event_callback)(void *state, struct pmu_event_info *info);
+
 void pmu_add_sys_aliases(struct perf_pmu *pmu);
 int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
 		     struct list_head *head_terms,
@@ -225,7 +186,7 @@ __u64 perf_pmu__format_bits(struct perf_pmu *pmu, const char *name);
 int perf_pmu__format_type(struct perf_pmu *pmu, const char *name);
 int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
 			  struct perf_pmu_info *info);
-struct perf_pmu_alias *perf_pmu__find_alias(struct perf_pmu *pmu, const char *event);
+int perf_pmu__find_event(struct perf_pmu *pmu, const char *event, void *state, pmu_event_callback cb);
 
 int perf_pmu__format_parse(struct perf_pmu *pmu, int dirfd, bool eager_load);
 void perf_pmu_format__set_value(void *format, int config, unsigned long *bits);
@@ -235,6 +196,9 @@ bool is_pmu_core(const char *name);
 bool perf_pmu__supports_legacy_cache(const struct perf_pmu *pmu);
 bool perf_pmu__auto_merge_stats(const struct perf_pmu *pmu);
 bool perf_pmu__have_event(const struct perf_pmu *pmu, const char *name);
+size_t perf_pmu__num_events(const struct perf_pmu *pmu);
+int perf_pmu__for_each_event(const struct perf_pmu *pmu, void *state, pmu_event_callback cb);
+
 /**
  * perf_pmu_is_software - is the PMU a software PMU as in it uses the
  *                        perf_sw_context in the kernel?
@@ -259,7 +223,6 @@ void pmu_add_cpu_aliases_table(struct perf_pmu *pmu,
 char *perf_pmu__getcpuid(struct perf_pmu *pmu);
 const struct pmu_events_table *pmu_events_table__find(void);
 const struct pmu_metrics_table *pmu_metrics_table__find(void);
-void perf_pmu_free_alias(struct perf_pmu_alias *alias);
 
 int perf_pmu__convert_scale(const char *scale, char **end, double *sval);
 
diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index c58ba9fb6a36..4dd5912617ff 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -258,219 +258,145 @@ int __weak perf_pmus__num_mem_pmus(void)
 struct sevent {
 	/** PMU for event. */
 	const struct perf_pmu *pmu;
-	/**
-	 * Optional event for name, desc, etc. If not present then this is a
-	 * selectable PMU and the event name is shown as "//".
-	 */
-	const struct perf_pmu_alias *event;
-	/** Is the PMU for the CPU? */
-	bool is_cpu;
+	const char *name;
+	const char* alias;
+	const char *scale_unit;
+	const char *desc;
+	const char *long_desc;
+	const char *encoding_desc;
+	const char *topic;
+	const char *pmu_name;
+	bool deprecated;
 };
 
 static int cmp_sevent(const void *a, const void *b)
 {
 	const struct sevent *as = a;
 	const struct sevent *bs = b;
-	const char *a_pmu_name = NULL, *b_pmu_name = NULL;
-	const char *a_name = "//", *a_desc = NULL, *a_topic = "";
-	const char *b_name = "//", *b_desc = NULL, *b_topic = "";
+	bool a_iscpu, b_iscpu;
 	int ret;
 
-	if (as->event) {
-		a_name = as->event->name;
-		a_desc = as->event->desc;
-		a_topic = as->event->topic ?: "";
-		a_pmu_name = as->event->pmu_name;
-	}
-	if (bs->event) {
-		b_name = bs->event->name;
-		b_desc = bs->event->desc;
-		b_topic = bs->event->topic ?: "";
-		b_pmu_name = bs->event->pmu_name;
-	}
 	/* Put extra events last. */
-	if (!!a_desc != !!b_desc)
-		return !!a_desc - !!b_desc;
+	if (!!as->desc != !!bs->desc)
+		return !!as->desc - !!bs->desc;
 
 	/* Order by topics. */
-	ret = strcmp(a_topic, b_topic);
+	ret = strcmp(as->topic ?: "", bs->topic ?: "");
 	if (ret)
 		return ret;
 
 	/* Order CPU core events to be first */
-	if (as->is_cpu != bs->is_cpu)
-		return as->is_cpu ? -1 : 1;
+	a_iscpu = as->pmu ? as->pmu->is_core : true;
+	b_iscpu = bs->pmu ? bs->pmu->is_core : true;
+	if (a_iscpu != b_iscpu)
+		return a_iscpu ? -1 : 1;
 
 	/* Order by PMU name. */
 	if (as->pmu != bs->pmu) {
-		a_pmu_name = a_pmu_name ?: (as->pmu->name ?: "");
-		b_pmu_name = b_pmu_name ?: (bs->pmu->name ?: "");
-		ret = strcmp(a_pmu_name, b_pmu_name);
+		ret = strcmp(as->pmu_name ?: "", bs->pmu_name ?: "");
 		if (ret)
 			return ret;
 	}
 
 	/* Order by event name. */
-	return strcmp(a_name, b_name);
+	return strcmp(as->name, bs->name);
 }
 
-static bool pmu_alias_is_duplicate(struct sevent *alias_a,
-				   struct sevent *alias_b)
+static bool pmu_alias_is_duplicate(struct sevent *a, struct sevent *b)
 {
-	const char *a_pmu_name = NULL, *b_pmu_name = NULL;
-	const char *a_name = "//", *b_name = "//";
-
-
-	if (alias_a->event) {
-		a_name = alias_a->event->name;
-		a_pmu_name = alias_a->event->pmu_name;
-	}
-	if (alias_b->event) {
-		b_name = alias_b->event->name;
-		b_pmu_name = alias_b->event->pmu_name;
-	}
-
 	/* Different names -> never duplicates */
-	if (strcmp(a_name, b_name))
+	if (strcmp(a->name ?: "//", b->name ?: "//"))
 		return false;
 
 	/* Don't remove duplicates for different PMUs */
-	a_pmu_name = a_pmu_name ?: (alias_a->pmu->name ?: "");
-	b_pmu_name = b_pmu_name ?: (alias_b->pmu->name ?: "");
-	return strcmp(a_pmu_name, b_pmu_name) == 0;
+	return strcmp(a->pmu_name, b->pmu_name) == 0;
 }
 
-static int sub_non_neg(int a, int b)
-{
-	if (b > a)
-		return 0;
-	return a - b;
-}
+struct events_callback_state {
+	struct sevent *aliases;
+	size_t aliases_len;
+	size_t index;
+};
 
-static char *format_alias(char *buf, int len, const struct perf_pmu *pmu,
-			  const struct perf_pmu_alias *alias)
+static int perf_pmus__print_pmu_events__callback(void *vstate,
+						struct pmu_event_info *info)
 {
-	struct parse_events_term *term;
-	int used = snprintf(buf, len, "%s/%s", pmu->name, alias->name);
-
-	list_for_each_entry(term, &alias->terms, list) {
-		if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
-			used += snprintf(buf + used, sub_non_neg(len, used),
-					",%s=%s", term->config,
-					term->val.str);
-	}
+	struct events_callback_state *state = vstate;
+	struct sevent *s;
 
-	if (sub_non_neg(len, used) > 0) {
-		buf[used] = '/';
-		used++;
+	if (state->index >= state->aliases_len) {
+		pr_err("Unexpected event %s/%s/\n", info->pmu->name, info->name);
+		return 1;
 	}
-	if (sub_non_neg(len, used) > 0) {
-		buf[used] = '\0';
-		used++;
-	} else
-		buf[len - 1] = '\0';
-
-	return buf;
+	s = &state->aliases[state->index];
+	s->pmu = info->pmu;
+#define COPY_STR(str) s->str = info->str ? strdup(info->str) : NULL
+	COPY_STR(name);
+	COPY_STR(alias);
+	COPY_STR(scale_unit);
+	COPY_STR(desc);
+	COPY_STR(long_desc);
+	COPY_STR(encoding_desc);
+	COPY_STR(topic);
+	COPY_STR(pmu_name);
+#undef COPY_STR
+	s->deprecated = info->deprecated;
+	state->index++;
+	return 0;
 }
 
 void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *print_state)
 {
 	struct perf_pmu *pmu;
-	struct perf_pmu_alias *event;
-	char buf[1024];
 	int printed = 0;
-	int len, j;
+	int len;
 	struct sevent *aliases;
+	struct events_callback_state state;
 
 	pmu = NULL;
 	len = 0;
-	while ((pmu = perf_pmus__scan(pmu)) != NULL) {
-		list_for_each_entry(event, &pmu->aliases, list)
-			len++;
-		if (pmu->selectable)
-			len++;
-	}
+	while ((pmu = perf_pmus__scan(pmu)) != NULL)
+		len += perf_pmu__num_events(pmu);
+
 	aliases = zalloc(sizeof(struct sevent) * len);
 	if (!aliases) {
 		pr_err("FATAL: not enough memory to print PMU events\n");
 		return;
 	}
 	pmu = NULL;
-	j = 0;
+	state = (struct events_callback_state) {
+		.aliases = aliases,
+		.aliases_len = len,
+		.index = 0,
+	};
 	while ((pmu = perf_pmus__scan(pmu)) != NULL) {
-		bool is_cpu = pmu->is_core;
-
-		list_for_each_entry(event, &pmu->aliases, list) {
-			aliases[j].event = event;
-			aliases[j].pmu = pmu;
-			aliases[j].is_cpu = is_cpu;
-			j++;
-		}
-		if (pmu->selectable) {
-			aliases[j].event = NULL;
-			aliases[j].pmu = pmu;
-			aliases[j].is_cpu = is_cpu;
-			j++;
-		}
+		perf_pmu__for_each_event(pmu, &state, perf_pmus__print_pmu_events__callback);
 	}
-	len = j;
 	qsort(aliases, len, sizeof(struct sevent), cmp_sevent);
-	for (j = 0; j < len; j++) {
-		const char *name, *alias = NULL, *scale_unit = NULL,
-			*desc = NULL, *long_desc = NULL,
-			*encoding_desc = NULL, *topic = NULL,
-			*pmu_name = NULL;
-		bool deprecated = false;
-		size_t buf_used;
-
+	for (int j = 0; j < len; j++) {
 		/* Skip duplicates */
 		if (j > 0 && pmu_alias_is_duplicate(&aliases[j], &aliases[j - 1]))
 			continue;
 
-		if (!aliases[j].event) {
-			/* A selectable event. */
-			pmu_name = aliases[j].pmu->name;
-			buf_used = snprintf(buf, sizeof(buf), "%s//", pmu_name) + 1;
-			name = buf;
-		} else {
-			if (aliases[j].event->desc) {
-				name = aliases[j].event->name;
-				buf_used = 0;
-			} else {
-				name = format_alias(buf, sizeof(buf), aliases[j].pmu,
-						    aliases[j].event);
-				if (aliases[j].is_cpu) {
-					alias = name;
-					name = aliases[j].event->name;
-				}
-				buf_used = strlen(buf) + 1;
-			}
-			pmu_name = aliases[j].event->pmu_name ?: (aliases[j].pmu->name ?: "");
-			if (strlen(aliases[j].event->unit) || aliases[j].event->scale != 1.0) {
-				scale_unit = buf + buf_used;
-				buf_used += snprintf(buf + buf_used, sizeof(buf) - buf_used,
-						"%G%s", aliases[j].event->scale,
-						aliases[j].event->unit) + 1;
-			}
-			desc = aliases[j].event->desc;
-			long_desc = aliases[j].event->long_desc;
-			topic = aliases[j].event->topic;
-			encoding_desc = buf + buf_used;
-			buf_used += snprintf(buf + buf_used, sizeof(buf) - buf_used,
-					"%s/%s/", pmu_name, aliases[j].event->str) + 1;
-			deprecated = aliases[j].event->deprecated;
-		}
 		print_cb->print_event(print_state,
-				pmu_name,
-				topic,
-				name,
-				alias,
-				scale_unit,
-				deprecated,
+				aliases[j].pmu_name,
+				aliases[j].topic,
+				aliases[j].name,
+				aliases[j].alias,
+				aliases[j].scale_unit,
+				aliases[j].deprecated,
 				"Kernel PMU event",
-				desc,
-				long_desc,
-				encoding_desc);
+				aliases[j].desc,
+				aliases[j].long_desc,
+				aliases[j].encoding_desc);
+		zfree(&aliases[j].name);
+		zfree(&aliases[j].alias);
+		zfree(&aliases[j].scale_unit);
+		zfree(&aliases[j].desc);
+		zfree(&aliases[j].long_desc);
+		zfree(&aliases[j].encoding_desc);
+		zfree(&aliases[j].topic);
+		zfree(&aliases[j].pmu_name);
 	}
 	if (printed && pager_in_use())
 		printf("\n");
-- 
2.42.0.rc1.204.g551eb34607-goog