diff options
| -rw-r--r-- | sys/netinet/tcp_input.c | 49 | ||||
| -rw-r--r-- | sys/netinet/tcp_reass.c | 49 | ||||
| -rw-r--r-- | sys/netinet/tcp_var.h | 19 |
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 |
