perf test: Add round trip test for sw and hw event names

It basically traverses the hardware and software event name arrays
creating an evlist with all events, then it uses perf_evsel__name to
check that the name is the expected one.

With it I noticed this problem:

[root@sandy ~]# perf test 10
10: roundtrip evsel->name check:invalid or unsupported event: 'CPU-migrations'
Run 'perf list' for a list of valid events
 FAILED!

Changed it to "cpu-migrations" in the software event arrays and it
worked.

This is to catch problems like the one reported by Joel Uckelman in
http://permalink.gmane.org/gmane.linux.kernel.perf.user/1016

Hardware cache events will be checked in the following patch.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-5jskfkuqvf2fi257zmni0ftz@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-test.c

@@ -1092,6 +1092,55 @@ static int test__perf_pmu(void)
 	return perf_pmu__test();
 }
 
+static int __perf_evsel__name_array_test(const char *names[], int nr_names)
+{
+	int i, err;
+	struct perf_evsel *evsel;
+        struct perf_evlist *evlist = perf_evlist__new(NULL, NULL);
+
+        if (evlist == NULL)
+                return -ENOMEM;
+
+	for (i = 0; i < nr_names; ++i) {
+		err = parse_events(evlist, names[i], 0);
+		if (err) {
+			pr_debug("failed to parse event '%s', err %d\n",
+				 names[i], err);
+			goto out_delete_evlist;
+		}
+	}
+
+	err = 0;
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		if (strcmp(perf_evsel__name(evsel), names[evsel->idx])) {
+			--err;
+			pr_debug("%s != %s\n", perf_evsel__name(evsel), names[evsel->idx]);
+		}
+	}
+
+out_delete_evlist:
+	perf_evlist__delete(evlist);
+	return err;
+}
+
+#define perf_evsel__name_array_test(names) \
+	__perf_evsel__name_array_test(names, ARRAY_SIZE(names))
+
+static int perf_evsel__roundtrip_name_test(void)
+{
+	int err = 0, ret = 0;
+
+	err = perf_evsel__name_array_test(perf_evsel__hw_names);
+	if (err)
+		ret = err;
+
+	err = perf_evsel__name_array_test(perf_evsel__sw_names);
+	if (err)
+		ret = err;
+
+	return ret;
+}
+
 static struct test {
 	const char *desc;
 	int (*func)(void);
@@ -1134,6 +1183,10 @@ static struct test {
 		.desc = "Test dso data interface",
 		.func = dso__test_data,
 	},
+	{
+		.desc = "roundtrip evsel->name check",
+		.func = perf_evsel__roundtrip_name_test,
+	},
 	{
 		.func = NULL,
 	},

tools/perf/util/evsel.c

@@ -68,7 +68,7 @@ struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx)
 	return evsel;
 }
 
-static const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX] = {
+const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX] = {
 	"cycles",
 	"instructions",
 	"cache-references",
@@ -131,12 +131,12 @@ static int perf_evsel__hw_name(struct perf_evsel *evsel, char *bf, size_t size)
 	return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
 }
 
-static const char *perf_evsel__sw_names[PERF_COUNT_SW_MAX] = {
+const char *perf_evsel__sw_names[PERF_COUNT_SW_MAX] = {
 	"cpu-clock",
 	"task-clock",
 	"page-faults",
 	"context-switches",
-	"CPU-migrations",
+	"cpu-migrations",
 	"minor-faults",
 	"major-faults",
 	"alignment-faults",

tools/perf/util/evsel.h

@@ -97,8 +97,10 @@ extern const char *perf_evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX]
 				       [PERF_EVSEL__MAX_ALIASES];
 extern const char *perf_evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX]
 					  [PERF_EVSEL__MAX_ALIASES];
-const char *perf_evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX]
-				       [PERF_EVSEL__MAX_ALIASES];
+extern const char *perf_evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX]
+					      [PERF_EVSEL__MAX_ALIASES];
+extern const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX];
+extern const char *perf_evsel__sw_names[PERF_COUNT_SW_MAX];
 int __perf_evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result,
 					    char *bf, size_t size);
 const char *perf_evsel__name(struct perf_evsel *evsel);