Index: sys/netinet/tcp_hostcache.c
===================================================================
--- sys/netinet/tcp_hostcache.c
+++ sys/netinet/tcp_hostcache.c
@@ -124,6 +124,10 @@
 static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0,
     "TCP Host cache");
 
+SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, enable, CTLFLAG_VNET | CTLFLAG_RW,
+    &VNET_NAME(tcp_use_hostcache), 0,
+    "Enable the TCP hostcache");
+
 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_VNET | CTLFLAG_RDTUN,
     &VNET_NAME(tcp_hostcache.cache_limit), 0,
     "Overall entry limit for hostcache");
@@ -272,6 +276,9 @@
 static struct hc_metrics *
 tcp_hc_lookup(struct in_conninfo *inc)
 {
+	if (!V_tcp_use_hostcache)
+		return NULL;
+
 	int hash;
 	struct hc_head *hc_head;
 	struct hc_metrics *hc_entry;
@@ -328,6 +335,9 @@
 static struct hc_metrics *
 tcp_hc_insert(struct in_conninfo *inc)
 {
+	if (!V_tcp_use_hostcache)
+		return NULL;
+
 	int hash;
 	struct hc_head *hc_head;
 	struct hc_metrics *hc_entry;
@@ -419,6 +429,9 @@
 void
 tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite)
 {
+	if (!V_tcp_use_hostcache)
+		return;
+
 	struct hc_metrics *hc_entry;
 
 	/*
@@ -458,6 +471,9 @@
 u_long
 tcp_hc_getmtu(struct in_conninfo *inc)
 {
+	if (!V_tcp_use_hostcache)
+		return 0;
+
 	struct hc_metrics *hc_entry;
 	u_long mtu;
 
@@ -480,6 +496,9 @@
 void
 tcp_hc_updatemtu(struct in_conninfo *inc, u_long mtu)
 {
+	if (!V_tcp_use_hostcache)
+		return;
+
 	struct hc_metrics *hc_entry;
 
 	/*
@@ -519,6 +538,9 @@
 void
 tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml)
 {
+	if (!V_tcp_use_hostcache)
+		return;
+
 	struct hc_metrics *hc_entry;
 
 	hc_entry = tcp_hc_lookup(inc);