socket buf speedup from thorpej@netbsd, okay art@ ericj@:

Make insertion of data into socket buffers O(C):
* Keep pointers to the first and last mbufs of the last record in the
  socket buffer.
* Use the sb_lastrecord pointer in the sbappend*() family of functions
  to avoid traversing the packet chain to find the last record.
* Add a new sbappend_stream() function for stream protocols which
  guarantee that there will never be more than one record in the
  socket buffer.  This function uses the sb_mbtail pointer to perform
  the data insertion.  Make TCP use sbappend_stream(). On a profiling
run, this makes sbappend of a TCP transmission using
a 1M socket buffer go from 50% of the time to .02% of the time. Thanks
to Bill Sommerfeld and YAMAMOTO Takashi for their debugging
assistance!

1 files changed, 4 insertions, 4 deletions

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 5b1e2bb9e33..6bdc83992d0 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_input.c,v 1.117 2002/06/09 16:26:11 itojun Exp $	*/
+/*	$OpenBSD: tcp_input.c,v 1.118 2002/08/08 17:07:32 provos Exp $	*/
 /*	$NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $	*/
 
 /*
@@ -300,7 +300,7 @@ present:
 		if (so->so_state & SS_CANTRCVMORE)
 			m_freem(q->ipqe_m);
 		else
-			sbappend(&so->so_rcv, q->ipqe_m);
+			sbappendstream(&so->so_rcv, q->ipqe_m);
 		pool_put(&ipqent_pool, q);
 		q = nq;
 	} while (q != NULL && q->ipqe_tcp->th_seq == tp->rcv_nxt);
@@ -1036,7 +1036,7 @@ findpcb:
 			 * to socket buffer.
 			 */
 			m_adj(m, iphlen + off);
-			sbappend(&so->so_rcv, m);
+			sbappendstream(&so->so_rcv, m);
 			sorwakeup(so);
 			TCP_SETUP_ACK(tp, tiflags);
 			if (tp->t_flags & TF_ACKNOW)
@@ -2115,7 +2115,7 @@ dodata:							/* XXX */
 			tcpstat.tcps_rcvbyte += tlen;
 			ND6_HINT(tp);
 			m_adj(m, hdroptlen);
-			sbappend(&so->so_rcv, m);
+			sbappendstream(&so->so_rcv, m);
 			sorwakeup(so);
 		} else {
 			m_adj(m, hdroptlen);