-/* Create the second region a page after the first one ends + safety gap */
-/* raw_heap_fd = shm_open("raw_heap", O_RDWR | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);*/
- raw_heap = mmalloc_attach(-1, (char*)(std_heap) + STD_HEAP_SIZE + getpagesize());
+#if defined HAVE_GNU_LD && !defined MMALLOC_WANT_OVERRIDE_LEGACY
+ /* use the system malloc for the model-checker data */
+ raw_heap = NULL;
+#else
+ /* Create the second region a page after the first one ends + safety gap */
+ raw_heap = xbt_mheap_new(-1, (char*)(std_heap) + STD_HEAP_SIZE + getpagesize());