|
|
@@ -1,4 +1,4 @@
|
|
|
-$Id: IMPLEMENTATION.txt,v 1.1 2005/02/10 16:38:09 gdt Exp $
|
|
|
+$Id: IMPLEMENTATION.txt,v 1.2 2005/02/15 17:10:03 gdt Exp $
|
|
|
|
|
|
This file contains notes about the internals of the BGP
|
|
|
implementation. The initial impetus is understanding the memory usage
|
|
|
@@ -150,10 +150,18 @@ bgpd.c
|
|
|
Question: How much memory does quagga's bgpd use as a function of
|
|
|
state received from peers?
|
|
|
|
|
|
-It seems that a struct bgp_info is kept for each prefix, and this has
|
|
|
-its own struct attr. aspath, etc. are 'interned' and shared.
|
|
|
-So, it seems that 144 bytes are used per received prefix, plus storage
|
|
|
-for all unique aspaths received.
|
|
|
+It seems that a struct bgp_info is kept for each prefix. The "struct
|
|
|
+attr *" is interned, and variables within that are interned. So, 40
|
|
|
+bytes are kept per received prefix, plus interned shared values. This
|
|
|
+could be 36 if 'int suppress' where changed to a u_char and moved to
|
|
|
+be with the other u_chars. Without MPLS, this could be 32 bytes.
|
|
|
+Note that 8 bytes of this is linked list overhead, meaning that 24
|
|
|
+bytes are the raw per-prefix storage requirements.
|
|
|
+
|
|
|
+Also, a struct bgp_damp_info is apparently maintained per route; this
|
|
|
+is fairly large (about 44 bytes).
|
|
|
+
|
|
|
+[TODO: the role of struct bgp_node.]
|
|
|
|
|
|
* TIME COMPLEXITY
|
|
|
|
gdt