diff --git a/xcache.ini b/xcache.ini
index 8c91913..4ca380e 100644
--- a/xcache.ini
+++ b/xcache.ini
@@ -18,6 +18,9 @@ xcache.admin.pass = ""
 
 [xcache]
 ; ini only settings, all the values here is default unless explained
+
+; select low level shm/allocator scheme implemenation
+xcache.shm_scheme =        "mmap"
 ; to disable: xcache.size=0
 ; to enable : xcache.size=any size > 0 and your system mmap allows
 xcache.size =                  0