Index: share/man/man4/sfxge.4
===================================================================
--- share/man/man4/sfxge.4
+++ share/man/man4/sfxge.4
@@ -93,10 +93,18 @@
 .It Va hw.sfxge.tx_dpl_get_max
 The maximum length of the deferred packet
 .Dq get-list
-for queued transmit
-packets, used only if the transmit queue lock can be acquired.
+for queued transmit packets (TCP and non-TCP), used only if the transmit
+queue lock can be acquired.
 If a packet is dropped, the
-.Va tx_early_drops
+.Va tx_get_overflow
+counter is incremented and the local sender receives ENOBUFS.
+The value must be greater than 0.
+.It Va hw.sfxge.tx_dpl_get_non_tcp_max
+The maximum number of non-TCP packets in the deferred packet
+.Dq get-list
+, used only if the transmit queue lock can be acquired.
+If packet is dropped, the
+.Va tx_get_non_tcp_overflow
 counter is incremented and the local sender receives ENOBUFS.
 The value must be greater than 0.
 .It Va hw.sfxge.tx_dpl_put_max
@@ -105,7 +113,7 @@
 for queued transmit
 packets, used if the transmit queue lock cannot be acquired.
 If a packet is dropped, the
-.Va tx_early_drops
+.Va tx_put_overflow
 counter is incremented and the local sender receives ENOBUFS.
 The value must be greater than or equal to 0.
 .El
Index: sys/dev/sfxge/sfxge_port.c
===================================================================
--- sys/dev/sfxge/sfxge_port.c
+++ sys/dev/sfxge/sfxge_port.c
@@ -48,7 +48,7 @@
 	unsigned int count;
 	int rc;
 
-	mtx_lock(&port->lock);
+	mtx_assert(&port->lock, MA_OWNED);
 
 	if (port->init_state != SFXGE_PORT_STARTED) {
 		rc = 0;
@@ -82,7 +82,6 @@
 
 	rc = ETIMEDOUT;
 out:
-	mtx_unlock(&port->lock);
 	return (rc);
 }
 
@@ -93,12 +92,16 @@
 	unsigned int id = arg2;
 	int rc;
 
+	mtx_lock(&sc->port.lock);
 	if ((rc = sfxge_mac_stat_update(sc)) != 0)
-		return (rc);
+		goto out;
 
-	return (SYSCTL_OUT(req,
-			  (uint64_t *)sc->port.mac_stats.decode_buf + id,
-			  sizeof(uint64_t)));
+	rc = SYSCTL_OUT(req,
+			(uint64_t *)sc->port.mac_stats.decode_buf + id,
+			sizeof(uint64_t));
+out:
+	mtx_unlock(&sc->port.lock);
+	return (rc);
 }
 
 static void
@@ -453,7 +456,7 @@
 	unsigned int count;
 	int rc;
 
-	mtx_lock(&port->lock);
+	mtx_assert(&port->lock, MA_OWNED);
 
 	if (port->init_state != SFXGE_PORT_STARTED) {
 		rc = 0;
@@ -487,7 +490,6 @@
 
 	rc = ETIMEDOUT;
 out:
-	mtx_unlock(&port->lock);
 	return (rc);
 }
 
@@ -498,12 +500,16 @@
 	unsigned int id = arg2;
 	int rc;
 
+	mtx_lock(&sc->port.lock);
 	if ((rc = sfxge_phy_stat_update(sc)) != 0)
-		return (rc);
+		goto out;
 
-	return (SYSCTL_OUT(req,
-			  (uint32_t *)sc->port.phy_stats.decode_buf + id,
-			  sizeof(uint32_t)));
+	rc = SYSCTL_OUT(req,
+			(uint32_t *)sc->port.phy_stats.decode_buf + id,
+			sizeof(uint32_t));
+out:
+	mtx_unlock(&sc->port.lock);
+	return (rc);
 }
 
 static void
Index: sys/dev/sfxge/sfxge_tx.h
===================================================================
--- sys/dev/sfxge/sfxge_tx.h
+++ sys/dev/sfxge/sfxge_tx.h
@@ -75,21 +75,29 @@
 	enum sfxge_tx_buf_flags	flags;
 };
 
-#define	SFXGE_TX_DPL_GET_PKT_LIMIT_DEFAULT	1024
-#define	SFXGE_TX_DPL_PUT_PKT_LIMIT_DEFAULT	64
+#define	SFXGE_TX_DPL_GET_PKT_LIMIT_DEFAULT		(64 * 1024)
+#define	SFXGE_TX_DPL_GET_NON_TCP_PKT_LIMIT_DEFAULT	1024
+#define	SFXGE_TX_DPL_PUT_PKT_LIMIT_DEFAULT		64
 
 /*
  * Deferred packet list.
  */
 struct sfxge_tx_dpl {
-	unsigned int		std_get_max;	/* Maximum number of packets
+	unsigned int	std_get_max;		/* Maximum number  of packets
 						 * in get list */
-	unsigned int		std_put_max;	/* Maximum number of packets
+	unsigned int	std_get_non_tcp_max;	/* Maximum number
+						 * of non-TCP packets
+						 * in get list */
+	unsigned int	std_put_max;		/* Maximum number of packets
 						 * in put list */
-	uintptr_t		std_put;	/* Head of put list. */
-	struct mbuf		*std_get;	/* Head of get list. */
-	struct mbuf		**std_getp;	/* Tail of get list. */
-	unsigned int		std_get_count;	/* Packets in get list. */
+	uintptr_t	std_put;		/* Head of put list. */
+	struct mbuf	*std_get;		/* Head of get list. */
+	struct mbuf	**std_getp;		/* Tail of get list. */
+	unsigned int	std_get_count;		/* Packets in get list. */
+	unsigned int	std_get_non_tcp_count;	/* Non-TCP packets
+						 * in get list */
+	unsigned int	std_get_hiwat;		/* Packets in get list
+						 * high watermark */
 };
 
 
@@ -166,7 +174,10 @@
 	unsigned long			tso_long_headers;
 	unsigned long			collapses;
 	unsigned long			drops;
-	unsigned long			early_drops;
+	unsigned long			get_overflow;
+	unsigned long			get_non_tcp_overflow;
+	unsigned long			put_overflow;
+	unsigned long			netdown_drops;
 
 	/* The following fields change more often, and are used mostly
 	 * on the completion path
Index: sys/dev/sfxge/sfxge_tx.c
===================================================================
--- sys/dev/sfxge/sfxge_tx.c
+++ sys/dev/sfxge/sfxge_tx.c
@@ -85,14 +85,23 @@
 TUNABLE_INT(SFXGE_PARAM_TX_DPL_GET_MAX, &sfxge_tx_dpl_get_max);
 SYSCTL_INT(_hw_sfxge, OID_AUTO, tx_dpl_get_max, CTLFLAG_RDTUN,
 	   &sfxge_tx_dpl_get_max, 0,
-	   "Maximum number of packets in deferred packet get-list");
+	   "Maximum number of any packets in deferred packet get-list");
+
+#define	SFXGE_PARAM_TX_DPL_GET_NON_TCP_MAX \
+	SFXGE_PARAM(tx_dpl_get_non_tcp_max)
+static int sfxge_tx_dpl_get_non_tcp_max =
+	SFXGE_TX_DPL_GET_NON_TCP_PKT_LIMIT_DEFAULT;
+TUNABLE_INT(SFXGE_PARAM_TX_DPL_GET_NON_TCP_MAX, &sfxge_tx_dpl_get_non_tcp_max);
+SYSCTL_INT(_hw_sfxge, OID_AUTO, tx_dpl_get_non_tcp_max, CTLFLAG_RDTUN,
+	   &sfxge_tx_dpl_get_non_tcp_max, 0,
+	   "Maximum number of non-TCP packets in deferred packet get-list");
 
 #define	SFXGE_PARAM_TX_DPL_PUT_MAX	SFXGE_PARAM(tx_dpl_put_max)
 static int sfxge_tx_dpl_put_max = SFXGE_TX_DPL_PUT_PKT_LIMIT_DEFAULT;
 TUNABLE_INT(SFXGE_PARAM_TX_DPL_PUT_MAX, &sfxge_tx_dpl_put_max);
 SYSCTL_INT(_hw_sfxge, OID_AUTO, tx_dpl_put_max, CTLFLAG_RDTUN,
 	   &sfxge_tx_dpl_put_max, 0,
-	   "Maximum number of packets in deferred packet put-list");
+	   "Maximum number of any packets in deferred packet put-list");
 
 #endif
 
@@ -152,6 +161,15 @@
 
 #ifdef SFXGE_HAVE_MQ
 
+static inline unsigned int
+sfxge_is_mbuf_non_tcp(struct mbuf *mbuf)
+{
+	/* Absense of TCP checksum flags does not mean that it is non-TCP
+	 * but it should be true if user wants to achieve high throughput.
+	 */
+	return (!(mbuf->m_pkthdr.csum_flags & (CSUM_IP_TCP | CSUM_IP6_TCP)));
+}
+
 /*
  * Reorder the put list and append it to the get list.
  */
@@ -163,6 +181,7 @@
 	volatile uintptr_t *putp;
 	uintptr_t put;
 	unsigned int count;
+	unsigned int non_tcp_count;
 
 	mtx_assert(&txq->lock, MA_OWNED);
 
@@ -181,9 +200,11 @@
 	get_next = NULL;
 
 	count = 0;
+	non_tcp_count = 0;
 	do {
 		struct mbuf *put_next;
 
+		non_tcp_count += sfxge_is_mbuf_non_tcp(mbuf);
 		put_next = mbuf->m_nextpkt;
 		mbuf->m_nextpkt = get_next;
 		get_next = mbuf;
@@ -197,6 +218,7 @@
 	*stdp->std_getp = get_next;
 	stdp->std_getp = get_tailp;
 	stdp->std_get_count += count;
+	stdp->std_get_non_tcp_count += non_tcp_count;
 }
 
 #endif /* SFXGE_HAVE_MQ */
@@ -387,6 +409,7 @@
 	struct sfxge_tx_dpl *stdp;
 	struct mbuf *mbuf, *next;
 	unsigned int count;
+	unsigned int non_tcp_count;
 	unsigned int pushed;
 	int rc;
 
@@ -401,6 +424,10 @@
 
 	mbuf = stdp->std_get;
 	count = stdp->std_get_count;
+	non_tcp_count = stdp->std_get_non_tcp_count;
+
+	if (count > stdp->std_get_hiwat)
+		stdp->std_get_hiwat = count;
 
 	while (count != 0) {
 		KASSERT(mbuf != NULL, ("mbuf == NULL"));
@@ -415,6 +442,7 @@
 
 		rc = sfxge_tx_queue_mbuf(txq, mbuf);
 		--count;
+		non_tcp_count -= sfxge_is_mbuf_non_tcp(mbuf);
 		mbuf = next;
 		if (rc != 0)
 			continue;
@@ -431,12 +459,16 @@
 
 	if (count == 0) {
 		KASSERT(mbuf == NULL, ("mbuf != NULL"));
+		KASSERT(non_tcp_count == 0,
+			("inconsistent TCP/non-TCP detection"));
 		stdp->std_get = NULL;
 		stdp->std_get_count = 0;
+		stdp->std_get_non_tcp_count = 0;
 		stdp->std_getp = &stdp->std_get;
 	} else {
 		stdp->std_get = mbuf;
 		stdp->std_get_count = count;
+		stdp->std_get_non_tcp_count = non_tcp_count;
 	}
 
 	if (txq->added != pushed)
@@ -496,8 +528,18 @@
 
 		sfxge_tx_qdpl_swizzle(txq);
 
-		if (stdp->std_get_count >= stdp->std_get_max)
+		if (stdp->std_get_count >= stdp->std_get_max) {
+			txq->get_overflow++;
 			return (ENOBUFS);
+		}
+		if (sfxge_is_mbuf_non_tcp(mbuf)) {
+			if (stdp->std_get_non_tcp_count >=
+			    stdp->std_get_non_tcp_max) {
+				txq->get_non_tcp_overflow++;
+				return (ENOBUFS);
+			}
+			stdp->std_get_non_tcp_count++;
+		}
 
 		*(stdp->std_getp) = mbuf;
 		stdp->std_getp = &mbuf->m_nextpkt;
@@ -518,8 +560,10 @@
 				old_len = mp->m_pkthdr.csum_data;
 			} else
 				old_len = 0;
-			if (old_len >= stdp->std_put_max)
+			if (old_len >= stdp->std_put_max) {
+				atomic_add_long(&txq->put_overflow, 1);
 				return (ENOBUFS);
+			}
 			mbuf->m_pkthdr.csum_data = old_len + 1;
 			mbuf->m_nextpkt = (void *)old;
 		} while (atomic_cmpset_ptr(putp, old, new) == 0);
@@ -540,6 +584,7 @@
 
 	if (!SFXGE_LINK_UP(txq->sc)) {
 		rc = ENETDOWN;
+		atomic_add_long(&txq->netdown_drops, 1);
 		goto fail;
 	}
 
@@ -577,7 +622,6 @@
 
 fail:
 	m_freem(m);
-	atomic_add_long(&txq->early_drops, 1);
 	return (rc);
 }
 
@@ -596,6 +640,7 @@
 	}
 	stdp->std_get = NULL;
 	stdp->std_get_count = 0;
+	stdp->std_get_non_tcp_count = 0;
 	stdp->std_getp = &stdp->std_get;
 
 	mtx_unlock(&txq->lock);
@@ -1411,6 +1456,13 @@
 		rc = EINVAL;
 		goto fail_tx_dpl_get_max;
 	}
+	if (sfxge_tx_dpl_get_non_tcp_max <= 0) {
+		log(LOG_ERR, "%s=%d must be greater than 0",
+		    SFXGE_PARAM_TX_DPL_GET_NON_TCP_MAX,
+		    sfxge_tx_dpl_get_non_tcp_max);
+		rc = EINVAL;
+		goto fail_tx_dpl_get_max;
+	}
 	if (sfxge_tx_dpl_put_max < 0) {
 		log(LOG_ERR, "%s=%d must be greater or equal to 0",
 		    SFXGE_PARAM_TX_DPL_PUT_MAX, sfxge_tx_dpl_put_max);
@@ -1422,6 +1474,7 @@
 	stdp = &txq->dpl;
 	stdp->std_put_max = sfxge_tx_dpl_put_max;
 	stdp->std_get_max = sfxge_tx_dpl_get_max;
+	stdp->std_get_non_tcp_max = sfxge_tx_dpl_get_non_tcp_max;
 	stdp->std_getp = &stdp->std_get;
 
 	mtx_init(&txq->lock, "txq", NULL, MTX_DEF);
@@ -1430,6 +1483,14 @@
 			SYSCTL_CHILDREN(txq_node), OID_AUTO,
 			"dpl_get_count", CTLFLAG_RD | CTLFLAG_STATS,
 			&stdp->std_get_count, 0, "");
+	SYSCTL_ADD_UINT(device_get_sysctl_ctx(sc->dev),
+			SYSCTL_CHILDREN(txq_node), OID_AUTO,
+			"dpl_get_non_tcp_count", CTLFLAG_RD | CTLFLAG_STATS,
+			&stdp->std_get_non_tcp_count, 0, "");
+	SYSCTL_ADD_UINT(device_get_sysctl_ctx(sc->dev),
+			SYSCTL_CHILDREN(txq_node), OID_AUTO,
+			"dpl_get_hiwat", CTLFLAG_RD | CTLFLAG_STATS,
+			&stdp->std_get_hiwat, 0, "");
 #endif
 
 	txq->type = type;
@@ -1467,7 +1528,10 @@
 	SFXGE_TX_STAT(tso_long_headers, tso_long_headers),
 	SFXGE_TX_STAT(tx_collapses, collapses),
 	SFXGE_TX_STAT(tx_drops, drops),
-	SFXGE_TX_STAT(tx_early_drops, early_drops),
+	SFXGE_TX_STAT(tx_get_overflow, get_overflow),
+	SFXGE_TX_STAT(tx_get_non_tcp_overflow, get_non_tcp_overflow),
+	SFXGE_TX_STAT(tx_put_overflow, put_overflow),
+	SFXGE_TX_STAT(tx_netdown_drops, netdown_drops),
 };
 
 static int