Index: netinet/tcp_reass.c
===================================================================
--- netinet/tcp_reass.c	(revision 224592)
+++ netinet/tcp_reass.c	(working copy)
@@ -174,6 +174,7 @@
 	struct tseg_qent *nq;
 	struct tseg_qent *te = NULL;
 	struct socket *so = tp->t_inpcb->inp_socket;
+	char *s = NULL;
 	int flags;
 
 	INP_WLOCK_ASSERT(tp->t_inpcb);
@@ -212,6 +213,11 @@
 		TCPSTAT_INC(tcps_rcvmemdrop);
 		m_freem(m);
 		*tlenp = 0;
+		if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL, NULL))) {
+			log(LOG_DEBUG, "%s; %s: queue limit reached, segment dropped\n",
+			    s, __func__);
+			free(s, M_TCPLOG);
+		}
 		return (0);
 	}
 
@@ -224,6 +230,12 @@
 		TCPSTAT_INC(tcps_rcvmemdrop);
 		m_freem(m);
 		*tlenp = 0;
+		if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL, NULL))) {
+			log(LOG_DEBUG, "%s; %s: global zone limit reached, segment dropped%s\n",
+			    s, __func__, (th->th_seq == tp->rcv_nxt ?
+			    ", would have drained queue!" : ""));
+			free(s, M_TCPLOG);
+		}
 		return (0);
 	}
 	tp->t_segqlen++;