[IPV4]: Move FIB lookup algorithm choice under IP_ADVANCED_ROUTING

Most users need not be concerned with a complex choice of what
FIB lookup algorithm to use.  So give them the safe default of
IP_FIB_HASH if IP_ADVANCED_ROUTING is disabled.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 690e88ba24846296c8c957da52ca5966bf142584..7bcfb84126d1527b488aa1efd96fa297729c4b52 100644 (file)
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -1,32 +1,6 @@
 #
 # IP configuration
 #
-choice 
-       prompt "Choose IP: FIB lookup"
-       depends on INET
-       default IP_FIB_HASH
-
-config IP_FIB_HASH
-       bool "FIB_HASH"
-       ---help---
-       Current FIB is very proven and good enough for most users.
-
-config IP_FIB_TRIE
-       bool "FIB_TRIE"
-       ---help---
-       Use new experimental LC-trie as FIB lookup algoritm. 
-        This improves lookup performance
-       
-       LC-trie is described in:
-       
-       IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
-       IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
-       An experimental study of compression methods for dynamic tries
-       Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
-       http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/
-       
-endchoice
-
 config IP_MULTICAST
        bool "IP: multicasting"
        depends on INET
@@ -79,6 +53,44 @@ config IP_ADVANCED_ROUTER
 
          If unsure, say N here.
 
+choice 
+       prompt "Choose IP: FIB lookup algorithm (choose FIB_HASH if unsure)"
+       depends on IP_ADVANCED_ROUTER
+       default IP_FIB_HASH
+
+config IP_FIB_HASH
+       bool "FIB_HASH"
+       ---help---
+       Current FIB is very proven and good enough for most users.
+
+config IP_FIB_TRIE
+       bool "FIB_TRIE"
+       ---help---
+       Use new experimental LC-trie as FIB lookup algoritm. 
+        This improves lookup performance if you have a large
+       number of routes.
+
+       LC-trie is a longest matching prefix lookup algorithm which
+       performs better than FIB_HASH for large routing tables.
+       But, it consumes more memory and is more complex.
+       
+       LC-trie is described in:
+       
+       IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
+       IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
+       An experimental study of compression methods for dynamic tries
+       Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
+       http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/
+       
+endchoice
+
+# If the user does not enable advanced routing, he gets the safe
+# default of the fib-hash algorithm.
+config IP_FIB_HASH
+       bool
+       depends on !IP_ADVANCED_ROUTER
+       default y
+
 config IP_MULTIPLE_TABLES
        bool "IP: policy routing"
        depends on IP_ADVANCED_ROUTER