--- a/src/hotspot/share/gc/z/zHeap.cpp	Mon Mar 18 11:50:40 2019 +0100
+++ b/src/hotspot/share/gc/z/zHeap.cpp	Mon Mar 18 11:50:40 2019 +0100
@@ -258,9 +258,7 @@
     // Map all pages
     ZPageTableIterator iter(&_page_table);
     for (ZPage* page; iter.next(&page);) {
-      if (!page->is_detached()) {
-        _page_allocator.map_page(page);
-      }
+      _page_allocator.map_page(page);
     }
   }
 }