mirror of
https://github.com/freebsd/freebsd-src
synced 2024-09-23 10:14:55 +00:00
Delete #ifdef notdef blocks containing old method of srtt calculation.
Requested by: davidg
This commit is contained in:
Garrett Wollman
parent
93902408b8
commit
a2352fc148
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=15396
|
|
@ -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;
|
||||
|
|
|
|||
|
|
@ -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;
|
||||
|
|
|
|||
|
|
@ -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
|
||||
|
|
|
|||
Loading…
Reference in a new issue