slower backoff than exponential

SCCS-vsn: sys/netinet/tcp_timer.c 4.20

diff --git a/usr/src/sys/netinet/tcp_timer.c b/usr/src/sys/netinet/tcp_timer.c
index 831146f..82d6acb 100644 (file)
--- a/usr/src/sys/netinet/tcp_timer.c
+++ b/usr/src/sys/netinet/tcp_timer.c
@@ -1,4 +1,4 @@
-/* tcp_timer.c 4.19 82/03/29 */
+/* tcp_timer.c 4.20 82/04/04 */

 
 #include "../h/param.h"
 #include "../h/systm.h"
 
 #include "../h/param.h"
 #include "../h/systm.h"


@@ -102,7 +102,10 @@ COUNT(TCP_CANCELTIMERS);
                tp->t_timer[i] = 0;
 }
 
                tp->t_timer[i] = 0;
 }
 

-int    tcprexmtprint;
+float  tcp_backoff[TCP_MAXRXTSHIFT] =
+    { 1.0, 1.2, 1.4, 1.7, 2.0, 3.0, 5.0, 8.0, 16.0, 32.0 };
+int    tcprexmtprint = 0;
+int    tcpexprexmtbackoff = 0;

 /*
  * TCP timer processing.
  */
 /*
  * TCP timer processing.
  */


@@ -136,9 +139,16 @@ COUNT(TCP_TIMERS);
                }
                TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
                    (int)tp->t_srtt, TCPTV_MIN, TCPTV_MAX);
                }
                TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
                    (int)tp->t_srtt, TCPTV_MIN, TCPTV_MAX);

-               TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
-                   tp->t_timer[TCPT_REXMT] << tp->t_rxtshift,
-                   TCPTV_MIN, TCPTV_MAX);
+               if (tcpexprexmtbackoff) {
+                       TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
+                           tp->t_timer[TCPT_REXMT] << tp->t_rxtshift,
+                           TCPTV_MIN, TCPTV_MAX);
+               } else {
+                       TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
+                           tp->t_timer[TCPT_REXMT] *
+                               tcp_backoff[tp->t_rxtshift - 1],
+                           TCPTV_MIN, TCPTV_MAX);
+               }

 if (tcprexmtprint)
 printf("rexmt set to %d\n", tp->t_timer[TCPT_REXMT]);
                tp->snd_nxt = tp->snd_una;
 if (tcprexmtprint)
 printf("rexmt set to %d\n", tp->t_timer[TCPT_REXMT]);
                tp->snd_nxt = tp->snd_una;