--- a/src/hotspot/share/gc/parallel/parMarkBitMap.cpp	Mon Nov 25 12:30:24 2019 +0100
+++ b/src/hotspot/share/gc/parallel/parMarkBitMap.cpp	Mon Nov 25 12:31:39 2019 +0100
@@ -90,7 +90,7 @@
     bool end_bit_ok = _end_bits.par_set_bit(end_bit);
     assert(end_bit_ok, "concurrency problem");
     DEBUG_ONLY(Atomic::inc(&mark_bitmap_count));
-    DEBUG_ONLY(Atomic::add(size, &mark_bitmap_size));
+    DEBUG_ONLY(Atomic::add(&mark_bitmap_size, size));
     return true;
   }
   return false;