--- a/src/hotspot/os/linux/os_linux.cpp	Tue Aug 20 10:46:23 2019 +0200
+++ b/src/hotspot/os/linux/os_linux.cpp	Tue Aug 20 10:11:53 2019 +0100
@@ -6185,6 +6185,10 @@
   return diff;
 }
 
+bool os::supports_map_sync() {
+  return true;
+}
+
 /////////////// Unit tests ///////////////
 
 #ifndef PRODUCT