From a1aa4b6c803d61e08c672ed170fb6dd85a00772f Mon Sep 17 00:00:00 2001
From: wollman <wollman@FreeBSD.org>
Date: Mon, 19 Jun 1995 16:45:33 +0000
Subject: Now that we've gone to all sorts of effort to allow TCP to cache some
 of its connection parameters, we want to keep statistics on how often this
 actually happens to see whether there is any work that needs to be done in
 TCP itself.

Suggested by: John Wroclawski <jtw@lcs.mit.edu>
---
 sys/netinet/tcp_subr.c     | 5 ++++-
 sys/netinet/tcp_timewait.c | 5 ++++-
 sys/netinet/tcp_var.h      | 5 ++++-
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 381824d..b2f96a2 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)tcp_subr.c	8.1 (Berkeley) 6/10/93
- * $Id: tcp_subr.c,v 1.10 1995/04/09 01:29:26 davidg Exp $
+ * $Id: tcp_subr.c,v 1.11 1995/05/30 08:09:58 rgrimes Exp $
  */
 
 #include <sys/param.h>
@@ -333,6 +333,7 @@ tcp_close(tp)
 				    (rt->rt_rmx.rmx_rtt + i) / 2;
 			else
 				rt->rt_rmx.rmx_rtt = i;
+			tcpstat.tcps_cachedrtt++;
 		}
 		if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) {
 			i = tp->t_rttvar *
@@ -342,6 +343,7 @@ tcp_close(tp)
 				    (rt->rt_rmx.rmx_rttvar + i) / 2;
 			else
 				rt->rt_rmx.rmx_rttvar = i;
+			tcpstat.tcps_cachedrttvar++;
 		}
 		/*
 		 * update the pipelimit (ssthresh) if it has been updated
@@ -366,6 +368,7 @@ tcp_close(tp)
 				    (rt->rt_rmx.rmx_ssthresh + i) / 2;
 			else
 				rt->rt_rmx.rmx_ssthresh = i;
+			tcpstat.tcps_cachedssthresh++;
 		}
 	}
 #endif /* RTV_RTT */
diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c
index 381824d..b2f96a2 100644
--- a/sys/netinet/tcp_timewait.c
+++ b/sys/netinet/tcp_timewait.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)tcp_subr.c	8.1 (Berkeley) 6/10/93
- * $Id: tcp_subr.c,v 1.10 1995/04/09 01:29:26 davidg Exp $
+ * $Id: tcp_subr.c,v 1.11 1995/05/30 08:09:58 rgrimes Exp $
  */
 
 #include <sys/param.h>
@@ -333,6 +333,7 @@ tcp_close(tp)
 				    (rt->rt_rmx.rmx_rtt + i) / 2;
 			else
 				rt->rt_rmx.rmx_rtt = i;
+			tcpstat.tcps_cachedrtt++;
 		}
 		if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) {
 			i = tp->t_rttvar *
@@ -342,6 +343,7 @@ tcp_close(tp)
 				    (rt->rt_rmx.rmx_rttvar + i) / 2;
 			else
 				rt->rt_rmx.rmx_rttvar = i;
+			tcpstat.tcps_cachedrttvar++;
 		}
 		/*
 		 * update the pipelimit (ssthresh) if it has been updated
@@ -366,6 +368,7 @@ tcp_close(tp)
 				    (rt->rt_rmx.rmx_ssthresh + i) / 2;
 			else
 				rt->rt_rmx.rmx_ssthresh = i;
+			tcpstat.tcps_cachedssthresh++;
 		}
 	}
 #endif /* RTV_RTT */
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 56d9f3e..c5f35d3 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)tcp_var.h	8.3 (Berkeley) 4/10/94
- * $Id: tcp_var.h,v 1.10 1995/03/16 18:15:07 bde Exp $
+ * $Id: tcp_var.h,v 1.11 1995/04/09 01:29:29 davidg Exp $
  */
 
 #ifndef _NETINET_TCP_VAR_H_
@@ -277,6 +277,9 @@ struct	tcpstat {
 	u_long	tcps_predack;		/* times hdr predict ok for acks */
 	u_long	tcps_preddat;		/* times hdr predict ok for data pkts */
 	u_long	tcps_pcbcachemiss;
+	u_long	tcps_cachedrtt;		/* times cached RTT in route updated */
+	u_long	tcps_cachedrttvar;	/* times cached rttvar updated */
+	u_long	tcps_cachedssthresh;	/* times cached ssthresh updated */
 };
 
 /*
-- 
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