diff --git a/mars.h b/mars.h
index b1645918..910bca75 100644
--- a/mars.h
+++ b/mars.h
@@ -286,6 +286,8 @@ extern const struct generic_brick_type *_bio_brick_type;
 extern const struct generic_brick_type *_aio_brick_type;
 extern const struct generic_brick_type *_sio_brick_type;
 
+#ifndef CONFIG_MARS_PREFER_SIO
+
 /* Kludge: our kernel threads will have no mm context, but need one
  * for stuff like ioctx_alloc() / aio_setup_ring() etc
  * which expect userspace resources.
@@ -341,6 +343,13 @@ static inline void unuse_fake_mm(void)
 	}
 }
 
+#else
+static inline void set_fake(void) {}
+static inline void put_fake(void) {}
+static inline void use_fake_mm(void) {}
+static inline void unuse_fake_mm(void) {}
+#endif
+
 /////////////////////////////////////////////////////////////////////////
 
 // init
diff --git a/mars_server.c b/mars_server.c
index 6cf9b314..8ff443d8 100644
--- a/mars_server.c
+++ b/mars_server.c
@@ -226,8 +226,6 @@ int handler_thread(void *data)
 	wake_up_interruptible(&brick->startup_event);
 
 	MARS_DBG("--------------- handler_thread starting on socket %p\n", sock);
-	//fake_mm();
-
         while (brick->cb_running && !kthread_should_stop()) {
 		struct mars_cmd cmd = {};
 
@@ -563,8 +561,6 @@ static int _server_thread(void *data)
 	char *id = my_id();
 	int status = 0;
 
-	//fake_mm();
-
 	MARS_INF("-------- server starting on host '%s' ----------\n", id);
 
         while (!kthread_should_stop() &&
diff --git a/sy_old/mars_light.c b/sy_old/mars_light.c
index bab15270..07edba20 100644
--- a/sy_old/mars_light.c
+++ b/sy_old/mars_light.c
@@ -992,8 +992,6 @@ int remote_thread(void *data)
 	real_peer = mars_translate_hostname(peer->peer);
 	MARS_INF("-------- remote thread starting on peer '%s' (%s)\n", peer->peer, real_peer);
 
-	//fake_mm();
-
 	status = mars_create_sockaddr(&sockaddr, real_peer);
 	if (unlikely(status < 0)) {
 		MARS_ERR("unusable remote address '%s' (%s)\n", real_peer, peer->peer);
@@ -3238,8 +3236,6 @@ static int light_thread(void *data)
 		goto done;
 	}	
 
-	//fake_mm();
-
 	MARS_INF("-------- starting as host '%s' ----------\n", id);
 
         while (_global.global_power.button || !list_empty(&_global.brick_anchor)) {