3 files changed, 34 insertions, 0 deletions
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 7cda749059a9..b922c8c297ca 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -9,6 +9,7 @@ perf-y += event.o
 perf-y += evlist.o
 perf-y += evsel.o
 perf-y += evsel_fprintf.o
+perf-y += evswitch.o
 perf-y += find_bit.o
 perf-y += get_current_dir_name.o
 perf-y += kallsyms.o
diff --git a/tools/perf/util/evswitch.c b/tools/perf/util/evswitch.c
new file mode 100644
index 000000000000..c87f988d81c8
--- /dev/null
+++ b/tools/perf/util/evswitch.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2019, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
+
+#include "evswitch.h"
+
+bool evswitch__discard(struct evswitch *evswitch, struct evsel *evsel)
+{
+	if (evswitch->on && evswitch->discarding) {
+		if (evswitch->on != evsel)
+			return true;
+
+		evswitch->discarding = false;
+
+		if (!evswitch->show_on_off_events)
+			return true;
+
+		return false;
+	}
+
+	if (evswitch->off && !evswitch->discarding) {
+		if (evswitch->off != evsel)
+			return false;
+
+		evswitch->discarding = true;
+
+		if (!evswitch->show_on_off_events)
+			return true;
+	}
+
+	return false;
+}
diff --git a/tools/perf/util/evswitch.h b/tools/perf/util/evswitch.h
index bb88e8002f39..bae3a22ad719 100644
--- a/tools/perf/util/evswitch.h
+++ b/tools/perf/util/evswitch.h
@@ -13,4 +13,6 @@ struct evswitch {
 	bool	     show_on_off_events;
 };
 
+bool evswitch__discard(struct evswitch *evswitch, struct evsel *evsel);
+
 #endif /* __PERF_EVSWITCH_H */