[IPV4] inet_peer: Group together avl_left, avl_right, v4daddr to speedup lookups on some CPUS

Lot of routers/embedded devices still use CPUS with 16/32 bytes cache
lines.  (486, Pentium, ...  PIII) It makes sense to group together
fields used at lookup time so they fit in one cache line.  This reduce
cache footprint and speedup lookups.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/inetpeer.h

@@ -17,14 +17,15 @@
 
 struct inet_peer
 {
+	/* group together avl_left,avl_right,v4daddr to speedup lookups */
 	struct inet_peer	*avl_left, *avl_right;
+	__be32			v4daddr;	/* peer's address */
+	__u16			avl_height;
+	__u16			ip_id_count;	/* IP ID for the next packet */
 	struct inet_peer	*unused_next, **unused_prevp;
 	__u32			dtime;		/* the time of last use of not
 						 * referenced entries */
 	atomic_t		refcnt;
-	__be32			v4daddr;	/* peer's address */
-	__u16			avl_height;
-	__u16			ip_id_count;	/* IP ID for the next packet */
 	atomic_t		rid;		/* Frag reception counter */
 	__u32			tcp_ts;
 	unsigned long		tcp_ts_stamp;