perf parse-events: Legacy cache names on all PMUs and lower priority

Prior behavior is to not look for legacy cache names in sysfs/JSON and
to create events on all core PMUs. New behavior is to look for
sysfs/JSON events first on all PMUs, for core PMUs add a legacy event
if the sysfs/JSON event isn't present.

This is done so that there is consistency with how event names in
terms are handled and their prioritization of sysfs/JSON over
legacy. It may make sense to use a legacy cache event name as an event
name on a non-core PMU so we should allow it.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Beeman Strong <beeman@rivosinc.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240416061533.921723-7-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/parse-events.c

@@ -442,17 +442,21 @@ bool parse_events__filter_pmu(const struct parse_events_state *parse_state,
 	return strcmp(parse_state->pmu_filter, pmu->name) != 0;
 }
 
+static int parse_events_add_pmu(struct parse_events_state *parse_state,
+				struct list_head *list, struct perf_pmu *pmu,
+				const struct parse_events_terms *const_parsed_terms,
+				bool auto_merge_stats);
+
 int parse_events_add_cache(struct list_head *list, int *idx, const char *name,
 			   struct parse_events_state *parse_state,
-			   struct parse_events_terms *head_config)
+			   struct parse_events_terms *parsed_terms)
 {
 	struct perf_pmu *pmu = NULL;
 	bool found_supported = false;
-	const char *config_name = get_config_name(head_config);
-	const char *metric_id = get_config_metric_id(head_config);
+	const char *config_name = get_config_name(parsed_terms);
+	const char *metric_id = get_config_metric_id(parsed_terms);
 
-	/* Legacy cache events are only supported by core PMUs. */
-	while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
+	while ((pmu = perf_pmus__scan(pmu)) != NULL) {
 		LIST_HEAD(config_terms);
 		struct perf_event_attr attr;
 		int ret;
@@ -460,6 +464,24 @@ int parse_events_add_cache(struct list_head *list, int *idx, const char *name,
 		if (parse_events__filter_pmu(parse_state, pmu))
 			continue;
 
+		if (perf_pmu__have_event(pmu, name)) {
+			/*
+			 * The PMU has the event so add as not a legacy cache
+			 * event.
+			 */
+			ret = parse_events_add_pmu(parse_state, list, pmu,
+						   parsed_terms,
+						   perf_pmu__auto_merge_stats(pmu));
+			if (ret)
+				return ret;
+			continue;
+		}
+
+		if (!pmu->is_core) {
+			/* Legacy cache events are only supported by core PMUs. */
+			continue;
+		}
+
 		memset(&attr, 0, sizeof(attr));
 		attr.type = PERF_TYPE_HW_CACHE;
 
@@ -469,11 +491,12 @@ int parse_events_add_cache(struct list_head *list, int *idx, const char *name,
 
 		found_supported = true;
 
-		if (head_config) {
-			if (config_attr(&attr, head_config, parse_state->error, config_term_common))
+		if (parsed_terms) {
+			if (config_attr(&attr, parsed_terms, parse_state->error,
+					config_term_common))
 				return -EINVAL;
 
-			if (get_config_terms(head_config, &config_terms))
+			if (get_config_terms(parsed_terms, &config_terms))
 				return -ENOMEM;
 		}
 

tools/perf/util/parse-events.h

@@ -203,7 +203,7 @@ int parse_events_add_tool(struct parse_events_state *parse_state,
 			  int tool_event);
 int parse_events_add_cache(struct list_head *list, int *idx, const char *name,
 			   struct parse_events_state *parse_state,
-			   struct parse_events_terms *head_config);
+			   struct parse_events_terms *parsed_terms);
 int parse_events__decode_legacy_cache(const char *name, int pmu_type, __u64 *config);
 int parse_events_add_breakpoint(struct parse_events_state *parse_state,
 				struct list_head *list,