release the memory of a big raw block to the system on free()

src/free.c

@@ -86,6 +86,6 @@ void free(void *ptr) {
         UNLOCK_GLOBAL();
 #endif /* WITH_ALLOCATOR_STATS */
 
-        /* release_memory(owner_raw_block); */
+        release_memory(owner_raw_block);
     }
 }