perf list: Simplify cache event printing

The current code computes an array of cache names then sorts and prints
them. Use a strlist to create a list of names that is sorted. Keep the
hybrid names, it is unclear how to generalize it, but drop the
computation of evt_pmus that is never used.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kang Minchul <tegongkang@gmail.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: Xin Gao <gaoxin@cdjrlc.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: http://lore.kernel.org/lkml/20221114210723.2749751-7-irogers@google.com
[ Fixed up clash with cf9f67b3 ("perf print-events: Remove redundant comparison with zero")]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/print-events.c

@@ -206,135 +206,59 @@ void print_sdt_events(const char *subsys_glob, const char *event_glob,
 
 int print_hwcache_events(const char *event_glob, bool name_only)
 {
-	unsigned int type, op, i, evt_i = 0, evt_num = 0, npmus = 0;
-	char name[64], new_name[128];
-	char **evt_list = NULL, **evt_pmus = NULL;
-	bool evt_num_known = false;
-	struct perf_pmu *pmu = NULL;
-
-	if (perf_pmu__has_hybrid()) {
-		npmus = perf_pmu__hybrid_pmu_num();
-		evt_pmus = zalloc(sizeof(char *) * npmus);
-		if (!evt_pmus)
-			goto out_enomem;
-	}
+	struct strlist *evt_name_list = strlist__new(NULL, NULL);
+	struct str_node *nd;
 
-restart:
-	if (evt_num_known) {
-		evt_list = zalloc(sizeof(char *) * evt_num);
-		if (!evt_list)
-			goto out_enomem;
+	if (!evt_name_list) {
+		pr_debug("Failed to allocate new strlist for hwcache events\n");
+		return -ENOMEM;
 	}
-
-	for (type = 0; type < PERF_COUNT_HW_CACHE_MAX; type++) {
-		for (op = 0; op < PERF_COUNT_HW_CACHE_OP_MAX; op++) {
+	for (int type = 0; type < PERF_COUNT_HW_CACHE_MAX; type++) {
+		for (int op = 0; op < PERF_COUNT_HW_CACHE_OP_MAX; op++) {
 			/* skip invalid cache type */
 			if (!evsel__is_cache_op_valid(type, op))
 				continue;
 
-			for (i = 0; i < PERF_COUNT_HW_CACHE_RESULT_MAX; i++) {
-				unsigned int hybrid_supported = 0, j;
-				bool supported;
+			for (int i = 0; i < PERF_COUNT_HW_CACHE_RESULT_MAX; i++) {
+				struct perf_pmu *pmu = NULL;
+				char name[64];
 
 				__evsel__hw_cache_type_op_res_name(type, op, i, name, sizeof(name));
 				if (event_glob != NULL && !strglobmatch(name, event_glob))
 					continue;
 
 				if (!perf_pmu__has_hybrid()) {
-					if (!is_event_supported(PERF_TYPE_HW_CACHE,
-								type | (op << 8) | (i << 16))) {
-						continue;
-					}
-				} else {
-					perf_pmu__for_each_hybrid_pmu(pmu) {
-						if (!evt_num_known) {
-							evt_num++;
-							continue;
-						}
-
-						supported = is_event_supported(
-							PERF_TYPE_HW_CACHE,
-							type | (op << 8) | (i << 16) |
-							((__u64)pmu->type << PERF_PMU_TYPE_SHIFT));
-						if (supported) {
-							snprintf(new_name, sizeof(new_name),
-								 "%s/%s/", pmu->name, name);
-							evt_pmus[hybrid_supported] =
-								strdup(new_name);
-							hybrid_supported++;
-						}
-					}
-
-					if (hybrid_supported == 0)
-						continue;
-				}
-
-				if (!evt_num_known) {
-					evt_num++;
+					if (is_event_supported(PERF_TYPE_HW_CACHE,
+							       type | (op << 8) | (i << 16)))
+						strlist__add(evt_name_list, name);
 					continue;
 				}
-
-				if ((hybrid_supported == 0) ||
-				    (hybrid_supported == npmus)) {
-					evt_list[evt_i] = strdup(name);
-					for (j = 0; j < npmus; j++)
-						zfree(&evt_pmus[j]);
-				} else {
-					for (j = 0; j < hybrid_supported; j++) {
-						evt_list[evt_i++] = evt_pmus[j];
-						evt_pmus[j] = NULL;
+				perf_pmu__for_each_hybrid_pmu(pmu) {
+					if (is_event_supported(PERF_TYPE_HW_CACHE,
+					    type | (op << 8) | (i << 16) |
+					    ((__u64)pmu->type << PERF_PMU_TYPE_SHIFT))) {
+						char new_name[128];
+							snprintf(new_name, sizeof(new_name),
+								 "%s/%s/", pmu->name, name);
+							strlist__add(evt_name_list, new_name);
 					}
-					continue;
 				}
-
-				if (evt_list[evt_i] == NULL)
-					goto out_enomem;
-				evt_i++;
 			}
 		}
 	}
 
-	if (!evt_num_known) {
-		evt_num_known = true;
-		goto restart;
-	}
-
-	for (evt_i = 0; evt_i < evt_num; evt_i++) {
-		if (!evt_list[evt_i])
-			break;
-	}
-
-	evt_num = evt_i;
-	qsort(evt_list, evt_num, sizeof(char *), cmp_string);
-	evt_i = 0;
-	while (evt_i < evt_num) {
+	strlist__for_each_entry(nd, evt_name_list) {
 		if (name_only) {
-			printf("%s ", evt_list[evt_i++]);
+			printf("%s ", nd->s);
 			continue;
 		}
-		printf("  %-50s [%s]\n", evt_list[evt_i++],
-				event_type_descriptors[PERF_TYPE_HW_CACHE]);
+		printf("  %-50s [%s]\n", nd->s, event_type_descriptors[PERF_TYPE_HW_CACHE]);
 	}
-	if (evt_num && pager_in_use())
+	if (!strlist__empty(evt_name_list) && pager_in_use())
 		printf("\n");
 
-out_free:
-	evt_num = evt_i;
-	for (evt_i = 0; evt_i < evt_num; evt_i++)
-		zfree(&evt_list[evt_i]);
-	zfree(&evt_list);
-
-	for (evt_i = 0; evt_i < npmus; evt_i++)
-		zfree(&evt_pmus[evt_i]);
-	zfree(&evt_pmus);
-	return evt_num;
-
-out_enomem:
-	printf("FATAL: not enough memory to print %s\n",
-		event_type_descriptors[PERF_TYPE_HW_CACHE]);
-	if (evt_list)
-		goto out_free;
-	return evt_num;
+	strlist__delete(evt_name_list);
+	return 0;
 }
 
 static void print_tool_event(const struct event_symbol *syms, const char *event_glob,