o Move the inflight sysctls to their own sub-tree under net.inet.tcp to be

more consistent with the other sysctls around it.

share/man/man4/tcp.4

@@ -382,7 +382,7 @@ code.
 For this reason, we use 200ms of slop and a near-0
 minimum, which gives us an effective minimum of 200ms (similar to
 .Tn Linux ) .
-.It Va inflight_enable
+.It Va inflight.enable
 Enable
 .Tn TCP
 bandwidth-delay product limiting.
@@ -406,20 +406,20 @@ Note that bandwidth-delay product limiting only effects
 the transmit side of a
 .Tn TCP
 connection.
-.It Va inflight_debug
+.It Va inflight.debug
 Enable debugging for the bandwidth-delay product algorithm.
 This may
 default to on (1), so if you enable the algorithm,
 you should probably also
 disable debugging by setting this variable to 0.
-.It Va inflight_min
+.It Va inflight.min
 This puts a lower bound on the bandwidth-delay product window, in bytes.
 A value of 1024 is typically used for debugging.
 6000-16000 is more typical in a production installation.
 Setting this value too low may result in
 slow ramp-up times for bursty connections.
 Setting this value too high effectively disables the algorithm.
-.It Va inflight_max
+.It Va inflight.max
 This puts an upper bound on the bandwidth-delay product window, in bytes.
 This value should not generally be modified, but may be used to set a
 global per-connection limit on queued data, potentially allowing you to
@@ -427,7 +427,7 @@ intentionally set a less than optimum limit, to smooth data flow over a
 network while still being able to specify huge internal
 .Tn TCP
 buffers.
-.It Va inflight_stab
+.It Va inflight.stab
 The bandwidth-delay product algorithm requires a slightly larger window
 than it otherwise calculates for stability.
 This parameter determines the extra window in maximal packets / 10.
@@ -438,17 +438,17 @@ come across a situation with very slow links where the
 time
 reduction of the default inflight code is not sufficient.
 If this case occurs, you should first try reducing
-.Va inflight_min
+.Va inflight.min
 and, if that does not
 work, reduce both
-.Va inflight_min
+.Va inflight.min
 and
-.Va inflight_stab ,
+.Va inflight.stab ,
 trying values of
 15, 10, or 5 for the latter.
 Never use a value less than 5.
 Reducing
-.Va inflight_stab
+.Va inflight.stab
 can lead to upwards of a 20% underutilization of the link
 as well as reducing the algorithm's ability to adapt to changing
 situations and should only be done as a last resort.

sys/netinet/tcp_subr.c

@@ -183,23 +183,27 @@ SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
  * 1024 exists only for debugging.  A good production default would be 
  * something like 6100.
  */
+SYSCTL_NODE(_net_inet_tcp, OID_AUTO, inflight, CTLFLAG_RW, 0,
+    "TCP inflight data limiting");
+
 static int	tcp_inflight_enable = 1;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, enable, CTLFLAG_RW,
     &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting");
 
 static int	tcp_inflight_debug = 0;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, debug, CTLFLAG_RW,
     &tcp_inflight_debug, 0, "Debug TCP inflight calculations");
 
 static int	tcp_inflight_min = 6144;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, min, CTLFLAG_RW,
     &tcp_inflight_min, 0, "Lower-bound for TCP inflight window");
 
 static int	tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, max, CTLFLAG_RW,
     &tcp_inflight_max, 0, "Upper-bound for TCP inflight window");
+
 static int	tcp_inflight_stab = 20;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, stab, CTLFLAG_RW,
     &tcp_inflight_stab, 0, "Inflight Algorithm Stabilization 20 = 2 packets");
 
 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack, CTLFLAG_RW, 0, "TCP SACK");

sys/netinet/tcp_timewait.c

@@ -183,23 +183,27 @@ SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
  * 1024 exists only for debugging.  A good production default would be 
  * something like 6100.
  */
+SYSCTL_NODE(_net_inet_tcp, OID_AUTO, inflight, CTLFLAG_RW, 0,
+    "TCP inflight data limiting");
+
 static int	tcp_inflight_enable = 1;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, enable, CTLFLAG_RW,
     &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting");
 
 static int	tcp_inflight_debug = 0;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, debug, CTLFLAG_RW,
     &tcp_inflight_debug, 0, "Debug TCP inflight calculations");
 
 static int	tcp_inflight_min = 6144;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, min, CTLFLAG_RW,
     &tcp_inflight_min, 0, "Lower-bound for TCP inflight window");
 
 static int	tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, max, CTLFLAG_RW,
     &tcp_inflight_max, 0, "Upper-bound for TCP inflight window");
+
 static int	tcp_inflight_stab = 20;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, stab, CTLFLAG_RW,
     &tcp_inflight_stab, 0, "Inflight Algorithm Stabilization 20 = 2 packets");
 
 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack, CTLFLAG_RW, 0, "TCP SACK");