--- old/src/hotspot/share/gc/z/zObjectAllocator.cpp	2019-11-21 11:55:18.949100864 +0100
+++ new/src/hotspot/share/gc/z/zObjectAllocator.cpp	2019-11-21 11:55:18.693096536 +0100
@@ -97,7 +97,7 @@
 
     retry:
       // Install new page
-      ZPage* const prev_page = Atomic::cmpxchg(new_page, shared_page, page);
+      ZPage* const prev_page = Atomic::cmpxchg(shared_page, page, new_page);
       if (prev_page != page) {
         if (prev_page == NULL) {
           // Previous page was retired, retry installing the new page