11546 Track TCP round-trip time in nanoseconds
Portions contributed by: Cody Peter Mello <cody.mello@joyent.com>
Portions contributed by: Brandon Baker <bbaker@delphix.com>
Reviewed by: Jason King <jason.king@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>

@@ -21,11 +21,11 @@
 
 /*
  * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2011, Joyent Inc. All rights reserved.
  * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
- * Copyright (c) 2013,2014 by Delphix. All rights reserved.
+ * Copyright (c) 2013, 2016 by Delphix. All rights reserved.
  * Copyright 2014, OmniTI Computer Consulting, Inc. All rights reserved.
  */
 /* Copyright (c) 1990 Mentat Inc. */
 
 #include <sys/types.h>

@@ -264,12 +264,10 @@
 } tcpt_t;
 
 /*
  * Functions called directly via squeue having a prototype of edesc_t.
  */
-void            tcp_input_listener(void *arg, mblk_t *mp, void *arg2,
-    ip_recv_attr_t *ira);
 void            tcp_input_data(void *arg, mblk_t *mp, void *arg2,
     ip_recv_attr_t *ira);
 static void     tcp_linger_interrupted(void *arg, mblk_t *mp, void *arg2,
     ip_recv_attr_t *dummy);
 

@@ -638,19 +636,13 @@
                 return (error);
 
         tcp->tcp_localnet = uinfo.iulp_localnet;
 
         if (uinfo.iulp_rtt != 0) {
-                clock_t rto;
-
-                tcp->tcp_rtt_sa = uinfo.iulp_rtt;
-                tcp->tcp_rtt_sd = uinfo.iulp_rtt_sd;
-                rto = (tcp->tcp_rtt_sa >> 3) + tcp->tcp_rtt_sd +
-                    tcps->tcps_rexmit_interval_extra +
-                    (tcp->tcp_rtt_sa >> 5);
-
-                TCP_SET_RTO(tcp, rto);
+                tcp->tcp_rtt_sa = MSEC2NSEC(uinfo.iulp_rtt);
+                tcp->tcp_rtt_sd = MSEC2NSEC(uinfo.iulp_rtt_sd);
+                tcp->tcp_rto = tcp_calculate_rto(tcp, tcps, 0);
         }
         if (uinfo.iulp_ssthresh != 0)
                 tcp->tcp_cwnd_ssthresh = uinfo.iulp_ssthresh;
         else
                 tcp->tcp_cwnd_ssthresh = TCP_MAX_LARGEWIN;

@@ -2332,11 +2324,10 @@
 void
 tcp_init_values(tcp_t *tcp, tcp_t *parent)
 {
         tcp_stack_t     *tcps = tcp->tcp_tcps;
         conn_t          *connp = tcp->tcp_connp;
-        clock_t         rto;
 
         ASSERT((connp->conn_family == AF_INET &&
             connp->conn_ipversion == IPV4_VERSION) ||
             (connp->conn_family == AF_INET6 &&
             (connp->conn_ipversion == IPV4_VERSION ||

@@ -2401,16 +2392,14 @@
          * will be close to tcp_rexmit_interval_initial.  By doing this, we
          * allow the algorithm to adjust slowly to large fluctuations of RTT
          * during first few transmissions of a connection as seen in slow
          * links.
          */
-        tcp->tcp_rtt_sa = tcp->tcp_rto_initial << 2;
-        tcp->tcp_rtt_sd = tcp->tcp_rto_initial >> 1;
-        rto = (tcp->tcp_rtt_sa >> 3) + tcp->tcp_rtt_sd +
-            tcps->tcps_rexmit_interval_extra + (tcp->tcp_rtt_sa >> 5) +
-            tcps->tcps_conn_grace_period;
-        TCP_SET_RTO(tcp, rto);
+        tcp->tcp_rtt_sa = MSEC2NSEC(tcp->tcp_rto_initial) << 2;
+        tcp->tcp_rtt_sd = MSEC2NSEC(tcp->tcp_rto_initial) >> 1;
+        tcp->tcp_rto = tcp_calculate_rto(tcp, tcps,
+            tcps->tcps_conn_grace_period);
 
         tcp->tcp_timer_backoff = 0;
         tcp->tcp_ms_we_have_waited = 0;
         tcp->tcp_last_recv_time = ddi_get_lbolt();
         tcp->tcp_cwnd_max = tcps->tcps_cwnd_max_;