perf mem: Clean up perf_mem_events__record_args()

The current code iterates all memory PMUs. It doesn't matter if the
system has only one memory PMU or multiple PMUs. The check of
perf_pmus__num_mem_pmus() is not required anymore.

The rec_tmp is not used in c2c and mem. Removing them as well.
Suggested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: ravi.bangoria@amd.com
Cc: james.clark@arm.com
Cc: will@kernel.org
Cc: mike.leach@linaro.org
Cc: renyu.zj@linux.alibaba.com
Cc: yuhaixin.yhx@linux.alibaba.com
Cc: tmricht@linux.ibm.com
Cc: atrajeev@linux.vnet.ibm.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: john.g.garry@oracle.com
Link: https://lore.kernel.org/r/20240123185036.3461837-7-kan.liang@linux.intel.comSigned-off-by: Namhyung Kim <namhyung@kernel.org>

tools/perf/builtin-c2c.c

@@ -3245,9 +3245,8 @@ static const char * const *record_mem_usage = __usage_record;
 
 static int perf_c2c__record(int argc, const char **argv)
 {
-	int rec_argc, i = 0, j, rec_tmp_nr = 0;
+	int rec_argc, i = 0, j;
 	const char **rec_argv;
-	char **rec_tmp;
 	int ret;
 	bool all_user = false, all_kernel = false;
 	bool event_set = false;
@@ -3285,12 +3284,6 @@ static int perf_c2c__record(int argc, const char **argv)
 	if (!rec_argv)
 		return -1;
 
-	rec_tmp = calloc(rec_argc + 1, sizeof(char *));
-	if (!rec_tmp) {
-		free(rec_argv);
-		return -1;
-	}
-
 	rec_argv[i++] = "record";
 
 	if (!event_set) {
@@ -3319,7 +3312,7 @@ static int perf_c2c__record(int argc, const char **argv)
 	rec_argv[i++] = "--phys-data";
 	rec_argv[i++] = "--sample-cpu";
 
-	ret = perf_mem_events__record_args(rec_argv, &i, rec_tmp, &rec_tmp_nr);
+	ret = perf_mem_events__record_args(rec_argv, &i);
 	if (ret)
 		goto out;
 
@@ -3346,10 +3339,6 @@ static int perf_c2c__record(int argc, const char **argv)
 
 	ret = cmd_record(i, rec_argv);
 out:
-	for (i = 0; i < rec_tmp_nr; i++)
-		free(rec_tmp[i]);
-
-	free(rec_tmp);
 	free(rec_argv);
 	return ret;
 }

tools/perf/builtin-mem.c

@@ -72,10 +72,9 @@ static const char * const *record_mem_usage = __usage;
 
 static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
 {
-	int rec_argc, i = 0, j, tmp_nr = 0;
+	int rec_argc, i = 0, j;
 	int start, end;
 	const char **rec_argv;
-	char **rec_tmp;
 	int ret;
 	bool all_user = false, all_kernel = false;
 	struct perf_mem_event *e;
@@ -116,15 +115,6 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
 	if (!rec_argv)
 		return -1;
 
-	/*
-	 * Save the allocated event name strings.
-	 */
-	rec_tmp = calloc(rec_argc + 1, sizeof(char *));
-	if (!rec_tmp) {
-		free(rec_argv);
-		return -1;
-	}
-
 	rec_argv[i++] = "record";
 
 	e = perf_pmu__mem_events_ptr(pmu, PERF_MEM_EVENTS__LOAD_STORE);
@@ -163,7 +153,7 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
 		rec_argv[i++] = "--data-page-size";
 
 	start = i;
-	ret = perf_mem_events__record_args(rec_argv, &i, rec_tmp, &tmp_nr);
+	ret = perf_mem_events__record_args(rec_argv, &i);
 	if (ret)
 		goto out;
 	end = i;
@@ -193,10 +183,6 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
 
 	ret = cmd_record(i, rec_argv);
 out:
-	for (i = 0; i < tmp_nr; i++)
-		free(rec_tmp[i]);
-
-	free(rec_tmp);
 	free(rec_argv);
 	return ret;
 }

tools/perf/util/mem-events.c

@@ -218,14 +218,14 @@ void perf_pmu__mem_events_list(struct perf_pmu *pmu)
 	}
 }
 
-int perf_mem_events__record_args(const char **rec_argv, int *argv_nr,
-				 char **rec_tmp, int *tmp_nr)
+int perf_mem_events__record_args(const char **rec_argv, int *argv_nr)
 {
 	const char *mnt = sysfs__mount();
 	struct perf_pmu *pmu = NULL;
-	int i = *argv_nr, k = 0;
 	struct perf_mem_event *e;
-
+	int i = *argv_nr;
+	const char *s;
+	char *copy;
 
 	while ((pmu = perf_pmus__scan_mem(pmu)) != NULL) {
 		for (int j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
@@ -240,30 +240,20 @@ int perf_mem_events__record_args(const char **rec_argv, int *argv_nr,
 				return -1;
 			}
 
-			if (perf_pmus__num_mem_pmus() == 1) {
-				rec_argv[i++] = "-e";
-				rec_argv[i++] = perf_pmu__mem_events_name(j, pmu);
-			} else {
-				const char *s = perf_pmu__mem_events_name(j, pmu);
-
-				if (!perf_pmu__mem_events_supported(mnt, pmu, e))
-					continue;
+			s = perf_pmu__mem_events_name(j, pmu);
+			if (!s || !perf_pmu__mem_events_supported(mnt, pmu, e))
+				continue;
 
-				rec_argv[i++] = "-e";
-				if (s) {
-					char *copy = strdup(s);
-					if (!copy)
-						return -1;
+			copy = strdup(s);
+			if (!copy)
+				return -1;
 
-					rec_argv[i++] = copy;
-					rec_tmp[k++] = copy;
-				}
-			}
+			rec_argv[i++] = "-e";
+			rec_argv[i++] = copy;
 		}
 	}
 
 	*argv_nr = i;
-	*tmp_nr = k;
 	return 0;
 }
 

tools/perf/util/mem-events.h

@@ -46,8 +46,7 @@ struct perf_pmu *perf_mem_events_find_pmu(void);
 bool is_mem_loads_aux_event(struct evsel *leader);
 
 void perf_pmu__mem_events_list(struct perf_pmu *pmu);
-int perf_mem_events__record_args(const char **rec_argv, int *argv_nr,
-				 char **rec_tmp, int *tmp_nr);
+int perf_mem_events__record_args(const char **rec_argv, int *argv_nr);
 
 int perf_mem__tlb_scnprintf(char *out, size_t sz, struct mem_info *mem_info);
 int perf_mem__lvl_scnprintf(char *out, size_t sz, struct mem_info *mem_info);