2 files changed, 7 insertions, 12 deletions

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 60eab8b..bc84a52 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -73,6 +73,8 @@ struct perf_session *perf_session__new(const char *filename, int mode, bool forc
 
 	if (mode == O_RDONLY && perf_session__open(self, force) < 0)
 		goto out_delete;
+
+	self->sample_type = perf_header__sample_type(&self->header);
 out:
 	return self;
 out_free:
@@ -302,11 +304,6 @@ int perf_session__process_events(struct perf_session *self,
 	page_size = getpagesize();
 
 	head = self->header.data_offset;
-	self->sample_type = perf_header__sample_type(&self->header);
-
-	err = -EINVAL;
-	if (ops->sample_type_check && ops->sample_type_check(self) < 0)
-		goto out_err;
 
 	if (!ops->full_paths) {
 		char bf[PATH_MAX];
@@ -394,13 +391,12 @@ out_err:
 	return err;
 }
 
-int perf_session__has_traces(struct perf_session *self)
+bool perf_session__has_traces(struct perf_session *self, const char *msg)
 {
 	if (!(self->sample_type & PERF_SAMPLE_RAW)) {
-		pr_err("No trace sample to read. Did you call perf record "
-		       "without -R?");
-		return -1;
+		pr_err("No trace sample to read. Did you call 'perf %s'?\n", msg);
+		return false;
 	}
 
-	return 0;
+	return true;
 }
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index a6951d2..5771ccb 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -40,7 +40,6 @@ struct perf_event_ops {
 	event_op	process_read_event;
 	event_op	process_throttle_event;
 	event_op	process_unthrottle_event;
-	int		(*sample_type_check)(struct perf_session *session);
 	unsigned long	total_unknown;
 	bool		full_paths;
 };
@@ -56,7 +55,7 @@ struct symbol **perf_session__resolve_callchain(struct perf_session *self,
 						struct ip_callchain *chain,
 						struct symbol **parent);
 
-int perf_session__has_traces(struct perf_session *self);
+bool perf_session__has_traces(struct perf_session *self, const char *msg);
 
 int perf_header__read_build_ids(int input, u64 offset, u64 file_size);