src/share/vm/runtime/arguments.cpp

@@ -1576,10 +1576,13 @@
 
   // Also checks that certain machines are slower with compressed oops
   // in vm_version initialization code.
 #endif // _LP64
 #endif // !ZERO
+
+  // Set up runtime image flags.
+  set_runtime_image_flags();
 }
 
 void Arguments::set_parallel_gc_flags() {
   assert(UseParallelGC || UseParallelOldGC, "Error");
   // Enable ParallelOld unless it was explicitly disabled (cmd line or rc file).

@@ -1831,10 +1834,20 @@
       }
     }
   }
 }
 
+  // Set up runtime image flags
+void Arguments::set_runtime_image_flags() {
+#ifdef _LP64
+  // Memory map image file by default on 64 bit machines.
+  if (FLAG_IS_DEFAULT(MemoryMapImage)) {
+    FLAG_SET_ERGO(bool, MemoryMapImage, true);
+  }
+#endif
+}
+
 // This must be called after ergonomics.
 void Arguments::set_bytecode_flags() {
   if (!RewriteBytecodes) {
     FLAG_SET_DEFAULT(RewriteFrequentPairs, false);
   }