diff --git a/messaging/impl_msgq.cc b/messaging/impl_msgq.cc
index 8f2c10a08..c27f073a1 100644
--- a/messaging/impl_msgq.cc
+++ b/messaging/impl_msgq.cc
@@ -155,7 +155,7 @@ int MSGQPubSocket::connect(Context *context, std::string endpoint, bool check_en
   }
 
   q = new msgq_queue_t;
-  int r = msgq_new_queue(q, endpoint.c_str(), DEFAULT_SEGMENT_SIZE);
+  int r = msgq_new_queue(q, endpoint.c_str(), DEFAULT_SEGMENT_SIZE, true);
   if (r != 0){
     return r;
   }
diff --git a/messaging/msgq.cc b/messaging/msgq.cc
index af93bbf60..dc87cb808 100644
--- a/messaging/msgq.cc
+++ b/messaging/msgq.cc
@@ -25,6 +25,7 @@
 
 #include "cereal/messaging/msgq.h"
 
+
 void sigusr2_handler(int signal) {
   assert(signal == SIGUSR2);
 }
@@ -83,7 +84,7 @@ void msgq_wait_for_subscriber(msgq_queue_t *q){
   return;
 }
 
-int msgq_new_queue(msgq_queue_t * q, const char * path, size_t size){
+int msgq_new_queue(msgq_queue_t * q, const char * path, size_t size, bool preallocate) {
   assert(size < 0xFFFFFFFF); // Buffer must be smaller than 2^32 bytes
   std::signal(SIGUSR2, sigusr2_handler);
 
@@ -105,6 +106,17 @@ int msgq_new_queue(msgq_queue_t * q, const char * path, size_t size){
     close(fd);
     return -1;
   }
+
+  if (preallocate && (std::getenv("MSGQ_PREALLOCATE") != nullptr)) {
+    do {
+      rc = fallocate(fd, 0, 0, size + sizeof(msgq_header_t));
+    } while (rc == EINTR);
+    if (rc < 0){
+      close(fd);
+      return -1;
+    }
+  }
+
   char * mem = (char*)mmap(NULL, size + sizeof(msgq_header_t), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
   close(fd);
 
diff --git a/messaging/msgq.h b/messaging/msgq.h
index 0a72a3864..c9e407170 100644
--- a/messaging/msgq.h
+++ b/messaging/msgq.h
@@ -57,7 +57,7 @@ int msgq_msg_init_size(msgq_msg_t *msg, size_t size);
 int msgq_msg_init_data(msgq_msg_t *msg, char * data, size_t size);
 int msgq_msg_close(msgq_msg_t *msg);
 
-int msgq_new_queue(msgq_queue_t * q, const char * path, size_t size);
+int msgq_new_queue(msgq_queue_t * q, const char * path, size_t size, bool preallocate = false);
 void msgq_close_queue(msgq_queue_t *q);
 void msgq_init_publisher(msgq_queue_t * q);
 void msgq_init_subscriber(msgq_queue_t * q);
diff --git a/services.py b/services.py
index 6436e3181..5a24c0125 100755
--- a/services.py
+++ b/services.py
@@ -126,4 +126,18 @@ def build_header():
 
 
 if __name__ == "__main__":
-  print(build_header())
+  #print(build_header())
+
+  # get ms
+  import capnp
+  from cereal import log
+  for k, v in SERVICE_LIST.items():
+    sz = None
+    dat = log.Event.new_message()
+    try:
+      dat.init(k)
+      sz = dat.total_size.word_count*8
+    except capnp.lib.capnp.KjException:
+      # TODO: lists
+      pass
+    print(k.ljust(30), sz)