svn commit: r216105 - in head/sys/netinet: . cc

[Lawrence Stewart]

Author: lstewart
Date: Thu Dec  2 01:36:00 2010
New Revision: 216105
URL: http://svn.freebsd.org/changeset/base/216105

Log:
  - Reinstantiate the after_idle hook call in tcp_output(), which got lost
    somewhere along the way due to mismerging r211464 in our development tree.
  
  - Capture the essence of r211464 in NewReno's after_idle() hook. We don't
    use V_ss_fltsz/V_ss_fltsz_local yet which needs to be revisited.
  
  Sponsored by:	FreeBSD Foundation
  Submitted by:	David Hayes <dahayes at swin edu au>
  MFC after:	9 weeks
  X-MFC with:	r215166

Modified:
  head/sys/netinet/cc/cc_newreno.c
  head/sys/netinet/tcp_output.c

Modified: head/sys/netinet/cc/cc_newreno.c
==============================================================================
--- head/sys/netinet/cc/cc_newreno.c	Thu Dec  2 01:14:45 2010	(r216104)
+++ head/sys/netinet/cc/cc_newreno.c	Thu Dec  2 01:36:00 2010	(r216105)
@@ -216,15 +216,28 @@ newreno_post_recovery(struct cc_var *ccv
 void
 newreno_after_idle(struct cc_var *ccv)
 {
+	int rw;
+
 	/*
-	 * We have been idle for "a while" and no acks are expected to clock out
-	 * any data we send -- slow start to get ack "clock" running again.
+	 * If we've been idle for more than one retransmit timeout the old
+	 * congestion window is no longer current and we have to reduce it to
+	 * the restart window before we can transmit again.
+	 *
+	 * The restart window is the initial window or the last CWND, whichever
+	 * is smaller.
+	 *
+	 * This is done to prevent us from flooding the path with a full CWND at
+	 * wirespeed, overloading router and switch buffers along the way.
+	 *
+	 * See RFC5681 Section 4.1. "Restarting Idle Connections".
 	 */
 	if (V_tcp_do_rfc3390)
-		CCV(ccv, snd_cwnd) = min(4 * CCV(ccv, t_maxseg),
+		rw = min(4 * CCV(ccv, t_maxseg),
 		    max(2 * CCV(ccv, t_maxseg), 4380));
 	else
-		CCV(ccv, snd_cwnd) = CCV(ccv, t_maxseg) * 2;
+		rw = CCV(ccv, t_maxseg) * 2;
+
+	CCV(ccv, snd_cwnd) = min(rw, CCV(ccv, snd_cwnd));
 }
 
 

Modified: head/sys/netinet/tcp_output.c
==============================================================================
--- head/sys/netinet/tcp_output.c	Thu Dec  2 01:14:45 2010	(r216104)
+++ head/sys/netinet/tcp_output.c	Thu Dec  2 01:36:00 2010	(r216105)
@@ -148,7 +148,7 @@ tcp_output(struct tcpcb *tp)
 {
 	struct socket *so = tp->t_inpcb->inp_socket;
 	long len, recwin, sendwin;
-	int off, flags, error, rw;
+	int off, flags, error;
 	struct mbuf *m;
 	struct ip *ip = NULL;
 	struct ipovly *ipov = NULL;
@@ -182,37 +182,8 @@ tcp_output(struct tcpcb *tp)
 	 * to send, then transmit; otherwise, investigate further.
 	 */
 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
-	if (idle && ticks - tp->t_rcvtime >= tp->t_rxtcur) {
-		/*
-		 * If we've been idle for more than one retransmit
-		 * timeout the old congestion window is no longer
-		 * current and we have to reduce it to the restart
-		 * window before we can transmit again.
-		 *
-		 * The restart window is the initial window or the last
-		 * CWND, whichever is smaller.
-		 * 
-		 * This is done to prevent us from flooding the path with
-		 * a full CWND at wirespeed, overloading router and switch
-		 * buffers along the way.
-		 *
-		 * See RFC5681 Section 4.1. "Restarting Idle Connections".
-		 */
-		if (V_tcp_do_rfc3390)
-			rw = min(4 * tp->t_maxseg,
-				 max(2 * tp->t_maxseg, 4380));
-#ifdef INET6
-		else if ((isipv6 ? in6_localaddr(&tp->t_inpcb->in6p_faddr) :
-			  in_localaddr(tp->t_inpcb->inp_faddr)))
-#else
-		else if (in_localaddr(tp->t_inpcb->inp_faddr))
-#endif
-			rw = V_ss_fltsz_local * tp->t_maxseg;
-		else
-			rw = V_ss_fltsz * tp->t_maxseg;
-
-		tp->snd_cwnd = min(rw, tp->snd_cwnd);
-	}
+	if (idle && ticks - tp->t_rcvtime >= tp->t_rxtcur)
+		cc_after_idle(tp);
 	tp->t_flags &= ~TF_LASTIDLE;
 	if (idle) {
 		if (tp->t_flags & TF_MORETOCOME) {