--- a/src/hotspot/share/services/mallocTracker.hpp	Fri Nov 15 20:29:11 2019 +0100
+++ b/src/hotspot/share/services/mallocTracker.hpp	Fri Nov 15 15:33:34 2019 -0500
@@ -70,8 +70,9 @@
     }
   }
 
-  inline void resize(long sz) {
+  inline void resize(ssize_t sz) {
     if (sz != 0) {
+      assert(sz >= 0 || _size >= size_t(-sz), "Must be");
       Atomic::add(size_t(sz), &_size);
       DEBUG_ONLY(_peak_size = MAX2(_size, _peak_size);)
     }
@@ -113,7 +114,7 @@
     _arena.deallocate(0);
   }
 
-  inline void record_arena_size_change(long sz) {
+  inline void record_arena_size_change(ssize_t sz) {
     _arena.resize(sz);
   }
 
@@ -361,7 +362,7 @@
     MallocMemorySummary::record_arena_free(flags);
   }
 
-  static inline void record_arena_size_change(int size, MEMFLAGS flags) {
+  static inline void record_arena_size_change(ssize_t size, MEMFLAGS flags) {
     MallocMemorySummary::record_arena_size_change(size, flags);
   }
  private: