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authorwollman <wollman@FreeBSD.org>1996-04-26 18:32:58 +0000
committerwollman <wollman@FreeBSD.org>1996-04-26 18:32:58 +0000
commitc9ab94c87851a11ea16d63c4d8871163784d2f90 (patch)
tree8f081e0ba595063c369760ab4ca922e569ff59f7
parent411e2af1bd2ec848d539381f8f00a3da5401690c (diff)
downloadFreeBSD-src-c9ab94c87851a11ea16d63c4d8871163784d2f90.zip
FreeBSD-src-c9ab94c87851a11ea16d63c4d8871163784d2f90.tar.gz
Delete #ifdef notdef blocks containing old method of srtt calculation.
Requested by: davidg
-rw-r--r--sys/netinet/tcp_input.c49
-rw-r--r--sys/netinet/tcp_reass.c49
-rw-r--r--sys/netinet/tcp_var.h19
3 files changed, 3 insertions, 114 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 270abcd..9132b33 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)tcp_input.c 8.12 (Berkeley) 5/24/95
- * $Id: tcp_input.c,v 1.41 1996/04/04 10:46:39 phk Exp $
+ * $Id: tcp_input.c,v 1.42 1996/04/09 07:01:51 pst Exp $
*/
#ifndef TUBA_INCLUDE
@@ -1831,47 +1831,6 @@ tcp_xmit_timer(tp, rtt)
register struct tcpcb *tp;
short rtt;
{
-#ifdef notdef
- register short delta;
-
- tcpstat.tcps_rttupdated++;
- tp->t_rttupdated++;
- if (tp->t_srtt != 0) {
- /*
- * srtt is stored as fixed point with 3 bits after the
- * binary point (i.e., scaled by 8). The following magic
- * is equivalent to the smoothing algorithm in rfc793 with
- * an alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed
- * point). Adjust rtt to origin 0.
- */
- delta = rtt - 1 - (tp->t_srtt >> TCP_RTT_SHIFT);
- if ((tp->t_srtt += delta) <= 0)
- tp->t_srtt = 1;
- /*
- * We accumulate a smoothed rtt variance (actually, a
- * smoothed mean difference), then set the retransmit
- * timer to smoothed rtt + 4 times the smoothed variance.
- * rttvar is stored as fixed point with 2 bits after the
- * binary point (scaled by 4). The following is
- * equivalent to rfc793 smoothing with an alpha of .75
- * (rttvar = rttvar*3/4 + |delta| / 4). This replaces
- * rfc793's wired-in beta.
- */
- if (delta < 0)
- delta = -delta;
- delta -= (tp->t_rttvar >> TCP_RTTVAR_SHIFT);
- if ((tp->t_rttvar += delta) <= 0)
- tp->t_rttvar = 1;
- } else {
- /*
- * No rtt measurement yet - use the unsmoothed rtt.
- * Set the variance to half the rtt (so our first
- * retransmit happens at 3*rtt).
- */
- tp->t_srtt = rtt << TCP_RTT_SHIFT;
- tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1);
- }
-#else /* Peterson paper */
register int delta;
tcpstat.tcps_rttupdated++;
@@ -1914,7 +1873,6 @@ tcp_xmit_timer(tp, rtt)
tp->t_srtt = rtt << TCP_RTT_SHIFT;
tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1);
}
-#endif
tp->t_rtt = 0;
tp->t_rxtshift = 0;
@@ -1929,13 +1887,8 @@ tcp_xmit_timer(tp, rtt)
* statistical, we have to test that we don't drop below
* the minimum feasible timer (which is 2 ticks).
*/
-#ifdef notdef
- TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
- tp->t_rttmin, TCPTV_REXMTMAX);
-#else /* Peterson */
TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
max(tp->t_rttmin, rtt + 2), TCPTV_REXMTMAX);
-#endif
/*
* We received an ack for a packet that wasn't retransmitted;
diff --git a/sys/netinet/tcp_reass.c b/sys/netinet/tcp_reass.c
index 270abcd..9132b33 100644
--- a/sys/netinet/tcp_reass.c
+++ b/sys/netinet/tcp_reass.c
@@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)tcp_input.c 8.12 (Berkeley) 5/24/95
- * $Id: tcp_input.c,v 1.41 1996/04/04 10:46:39 phk Exp $
+ * $Id: tcp_input.c,v 1.42 1996/04/09 07:01:51 pst Exp $
*/
#ifndef TUBA_INCLUDE
@@ -1831,47 +1831,6 @@ tcp_xmit_timer(tp, rtt)
register struct tcpcb *tp;
short rtt;
{
-#ifdef notdef
- register short delta;
-
- tcpstat.tcps_rttupdated++;
- tp->t_rttupdated++;
- if (tp->t_srtt != 0) {
- /*
- * srtt is stored as fixed point with 3 bits after the
- * binary point (i.e., scaled by 8). The following magic
- * is equivalent to the smoothing algorithm in rfc793 with
- * an alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed
- * point). Adjust rtt to origin 0.
- */
- delta = rtt - 1 - (tp->t_srtt >> TCP_RTT_SHIFT);
- if ((tp->t_srtt += delta) <= 0)
- tp->t_srtt = 1;
- /*
- * We accumulate a smoothed rtt variance (actually, a
- * smoothed mean difference), then set the retransmit
- * timer to smoothed rtt + 4 times the smoothed variance.
- * rttvar is stored as fixed point with 2 bits after the
- * binary point (scaled by 4). The following is
- * equivalent to rfc793 smoothing with an alpha of .75
- * (rttvar = rttvar*3/4 + |delta| / 4). This replaces
- * rfc793's wired-in beta.
- */
- if (delta < 0)
- delta = -delta;
- delta -= (tp->t_rttvar >> TCP_RTTVAR_SHIFT);
- if ((tp->t_rttvar += delta) <= 0)
- tp->t_rttvar = 1;
- } else {
- /*
- * No rtt measurement yet - use the unsmoothed rtt.
- * Set the variance to half the rtt (so our first
- * retransmit happens at 3*rtt).
- */
- tp->t_srtt = rtt << TCP_RTT_SHIFT;
- tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1);
- }
-#else /* Peterson paper */
register int delta;
tcpstat.tcps_rttupdated++;
@@ -1914,7 +1873,6 @@ tcp_xmit_timer(tp, rtt)
tp->t_srtt = rtt << TCP_RTT_SHIFT;
tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1);
}
-#endif
tp->t_rtt = 0;
tp->t_rxtshift = 0;
@@ -1929,13 +1887,8 @@ tcp_xmit_timer(tp, rtt)
* statistical, we have to test that we don't drop below
* the minimum feasible timer (which is 2 ticks).
*/
-#ifdef notdef
- TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
- tp->t_rttmin, TCPTV_REXMTMAX);
-#else /* Peterson */
TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
max(tp->t_rttmin, rtt + 2), TCPTV_REXMTMAX);
-#endif
/*
* We received an ack for a packet that wasn't retransmitted;
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 3035143..f8ad951 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
- * $Id: tcp_var.h,v 1.30 1996/02/27 15:12:53 bde Exp $
+ * $Id: tcp_var.h,v 1.31 1996/03/22 18:09:21 wollman Exp $
*/
#ifndef _NETINET_TCP_VAR_H_
@@ -191,18 +191,11 @@ struct rmxp_tao {
* and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
* binary point, and is smoothed with an ALPHA of 0.75.
*/
-#ifdef notdef
-#define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */
-#define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
-#define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */
-#define TCP_RTTVAR_SHIFT 2 /* shift for rttvar; 2 bits */
-#else
#define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */
#define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */
#define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */
#define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */
#define TCP_DELTA_SHIFT 2 /* see tcp_input.c */
-#endif
/*
* The initial retransmission should happen at rtt + 4 * rttvar.
@@ -214,25 +207,15 @@ struct rmxp_tao {
* 1.5 tick we need. But, because the bias is
* statistical, we have to test that we don't drop below
* the minimum feasible timer (which is 2 ticks).
-#ifdef notdef
- * This macro assumes that the value of TCP_RTTVAR_SCALE
- * is the same as the multiplier for rttvar.
-#else
* This version of the macro adapted from a paper by Lawrence
* Brakmo and Larry Peterson which outlines a problem caused
* by insufficient precision in the original implementation,
* which results in inappropriately large RTO values for very
* fast networks.
-#endif
*/
-#ifdef notdef
-#define TCP_REXMTVAL(tp) \
- (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar)
-#else
#define TCP_REXMTVAL(tp) \
((((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_RTTVAR_SHIFT)) \
+ ((tp)->t_rttvar) >> TCP_RTTVAR_SHIFT))
-#endif
/* XXX
* We want to avoid doing m_pullup on incoming packets but that
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