diff --git a/tools/perf/builtin-help.c b/tools/perf/builtin-help.c
index 411ee5664e98..178b88ae3d2f 100644
--- a/tools/perf/builtin-help.c
+++ b/tools/perf/builtin-help.c
@@ -414,7 +414,7 @@ static int show_html_page(const char *perf_cmd)
 int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	bool show_all = false;
-	enum help_format help_format = HELP_FORMAT_NONE;
+	enum help_format help_format = HELP_FORMAT_MAN;
 	struct option builtin_help_options[] = {
 	OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
 	OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index dec8ced61fb0..7aaee39f6774 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -56,6 +56,10 @@ static int trace__read_syscall_info(struct trace *trace, int id)
 {
 	char tp_name[128];
 	struct syscall *sc;
+	const char *name = audit_syscall_to_name(id, trace->audit_machine);
+
+	if (name == NULL)
+		return -1;
 
 	if (id > trace->syscalls.max) {
 		struct syscall *nsyscalls = realloc(trace->syscalls.table, (id + 1) * sizeof(*sc));
@@ -75,11 +79,8 @@ static int trace__read_syscall_info(struct trace *trace, int id)
 	}
 
 	sc = trace->syscalls.table + id;
-	sc->name = audit_syscall_to_name(id, trace->audit_machine);
-	if (sc->name == NULL)
-		return -1;
-
-	sc->fmt = syscall_fmt__find(sc->name);
+	sc->name = name;
+	sc->fmt  = syscall_fmt__find(sc->name);
 
 	snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->name);
 	sc->tp_format = event_format__new("syscalls", tp_name);
@@ -267,6 +268,13 @@ static int trace__run(struct trace *trace)
 			if (evlist->threads->map[0] == -1 || evlist->threads->nr > 1)
 				printf("%d ", sample.tid);
 
+			if (sample.raw_data == NULL) {
+				printf("%s sample with no payload for tid: %d, cpu %d, raw_size=%d, skipping...\n",
+				       perf_evsel__name(evsel), sample.tid,
+				       sample.cpu, sample.raw_size);
+				continue;
+			}
+
 			handler = evsel->handler.func;
 			handler(trace, evsel, &sample);
 		}
diff --git a/tools/perf/util/parse-events-test.c b/tools/perf/util/parse-events-test.c
index 28c18d1d52c3..516ecd9ddd6e 100644
--- a/tools/perf/util/parse-events-test.c
+++ b/tools/perf/util/parse-events-test.c
@@ -513,7 +513,8 @@ static int test__group1(struct perf_evlist *evlist)
 	TEST_ASSERT_VAL("wrong exclude_user", !evsel->attr.exclude_user);
 	TEST_ASSERT_VAL("wrong exclude_kernel", evsel->attr.exclude_kernel);
 	TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
-	TEST_ASSERT_VAL("wrong exclude guest", !evsel->attr.exclude_guest);
+	/* use of precise requires exclude_guest */
+	TEST_ASSERT_VAL("wrong exclude guest", evsel->attr.exclude_guest);
 	TEST_ASSERT_VAL("wrong exclude host", !evsel->attr.exclude_host);
 	TEST_ASSERT_VAL("wrong precise_ip", evsel->attr.precise_ip == 2);
 	TEST_ASSERT_VAL("wrong leader", evsel->leader == leader);
@@ -599,7 +600,8 @@ static int test__group3(struct perf_evlist *evlist __maybe_unused)
 	TEST_ASSERT_VAL("wrong exclude_user", evsel->attr.exclude_user);
 	TEST_ASSERT_VAL("wrong exclude_kernel", !evsel->attr.exclude_kernel);
 	TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
-	TEST_ASSERT_VAL("wrong exclude guest", !evsel->attr.exclude_guest);
+	/* use of precise requires exclude_guest */
+	TEST_ASSERT_VAL("wrong exclude guest", evsel->attr.exclude_guest);
 	TEST_ASSERT_VAL("wrong exclude host", !evsel->attr.exclude_host);
 	TEST_ASSERT_VAL("wrong precise_ip", evsel->attr.precise_ip == 3);
 	TEST_ASSERT_VAL("wrong leader", evsel->leader == leader);
@@ -662,7 +664,8 @@ static int test__group4(struct perf_evlist *evlist __maybe_unused)
 	TEST_ASSERT_VAL("wrong exclude_user", !evsel->attr.exclude_user);
 	TEST_ASSERT_VAL("wrong exclude_kernel", evsel->attr.exclude_kernel);
 	TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
-	TEST_ASSERT_VAL("wrong exclude guest", !evsel->attr.exclude_guest);
+	/* use of precise requires exclude_guest */
+	TEST_ASSERT_VAL("wrong exclude guest", evsel->attr.exclude_guest);
 	TEST_ASSERT_VAL("wrong exclude host", !evsel->attr.exclude_host);
 	TEST_ASSERT_VAL("wrong precise_ip", evsel->attr.precise_ip == 1);
 	TEST_ASSERT_VAL("wrong group name", !evsel->group_name);
@@ -676,7 +679,8 @@ static int test__group4(struct perf_evlist *evlist __maybe_unused)
 	TEST_ASSERT_VAL("wrong exclude_user", evsel->attr.exclude_user);
 	TEST_ASSERT_VAL("wrong exclude_kernel", !evsel->attr.exclude_kernel);
 	TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
-	TEST_ASSERT_VAL("wrong exclude guest", !evsel->attr.exclude_guest);
+	/* use of precise requires exclude_guest */
+	TEST_ASSERT_VAL("wrong exclude guest", evsel->attr.exclude_guest);
 	TEST_ASSERT_VAL("wrong exclude host", !evsel->attr.exclude_host);
 	TEST_ASSERT_VAL("wrong precise_ip", evsel->attr.precise_ip == 2);
 	TEST_ASSERT_VAL("wrong leader", evsel->leader == leader);
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index fb4b7ea6752f..8b3e5939afb6 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -39,7 +39,6 @@ int thread__set_comm(struct thread *self, const char *comm)
 	err = self->comm == NULL ? -ENOMEM : 0;
 	if (!err) {
 		self->comm_set = true;
-		map_groups__flush(&self->mg);
 	}
 	return err;
 }