--- a/src/hotspot/share/gc/g1/g1ParallelCleaning.cpp	Mon Nov 25 12:32:40 2019 +0100
+++ b/src/hotspot/share/gc/g1/g1ParallelCleaning.cpp	Mon Nov 25 12:33:15 2019 +0100
@@ -39,7 +39,7 @@
     return false;
   }
 
-  return Atomic::cmpxchg(1, &_cleaning_claimed, 0) == 0;
+  return Atomic::cmpxchg(&_cleaning_claimed, 0, 1) == 0;
 }
 
 void JVMCICleaningTask::work(bool unloading_occurred) {