[XFRM]: Add packet processing statistics option.

Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/xfrm/Kconfig

@@ -35,6 +35,16 @@ config XFRM_MIGRATE
 
 	  If unsure, say N.
 
+config XFRM_STATISTICS
+	bool "Transformation statistics (EXPERIMENTAL)"
+	depends on XFRM && PROC_FS && EXPERIMENTAL
+	---help---
+	  This statistics is not a SNMP/MIB specification but shows
+	  statistics about transformation error (or almost error) factor
+	  at packet processing for developer.
+
+	  If unsure, say N.
+
 config NET_KEY
 	tristate "PF_KEY sockets"
 	select XFRM