src/hotspot/share/gc/z/zPage.inline.hpp

@@ -253,11 +253,11 @@
     if (new_top > end()) {
       // Not enough space left
       return 0;
     }
 
-    const uintptr_t prev_top = Atomic::cmpxchg(new_top, &_top, addr);
+    const uintptr_t prev_top = Atomic::cmpxchg(&_top, addr, new_top);
     if (prev_top == addr) {
       // Success
       return ZAddress::good(addr);
     }
 

@@ -297,11 +297,11 @@
     if (new_top != offset) {
       // Failed to undo allocation, not the last allocated object
       return false;
     }
 
-    const uintptr_t prev_top = Atomic::cmpxchg(new_top, &_top, old_top);
+    const uintptr_t prev_top = Atomic::cmpxchg(&_top, old_top, new_top);
     if (prev_top == old_top) {
       // Success
       return true;
     }