diff -r c97db0855565 -r 758c07667682 src/share/vm/gc_implementation/shared/gSpaceCounters.hpp
--- a/src/share/vm/gc_implementation/shared/gSpaceCounters.hpp	Tue Feb 04 17:38:01 2020 +0800
+++ b/src/share/vm/gc_implementation/shared/gSpaceCounters.hpp	Tue Feb 04 18:13:14 2020 +0800
@@ -63,7 +63,7 @@
   }
 
   inline void update_used() {
-    _used->set_value(_gen->used());
+    _used->set_value(_gen->used_stable());
   }
 
   // special version of update_used() to allow the used value to be
@@ -107,7 +107,7 @@
     GenerationUsedHelper(Generation* g) : _gen(g) { }
 
     inline jlong take_sample() {
-      return _gen->used();
+      return _gen->used_stable();
     }
 };