Index: if.c
===================================================================
RCS file: /cvs/src/sys/net/if.c,v
retrieving revision 1.548
diff -u -p -r1.548 if.c
--- if.c	2 Mar 2018 15:52:11 -0000	1.548
+++ if.c	28 Mar 2018 01:28:03 -0000
@@ -607,6 +607,7 @@ if_attach_common(struct ifnet *ifp)
 	ifp->if_snd.ifq_ifqs[0] = &ifp->if_snd;
 	ifp->if_ifqs = ifp->if_snd.ifq_ifqs;
 	ifp->if_nifqs = 1;
+	ifp->if_sndmit = IF_SNDMIT_DEFAULT;
 
 	ifiq_init(&ifp->if_rcv, ifp, 0);
 
Index: if_var.h
===================================================================
RCS file: /cvs/src/sys/net/if_var.h,v
retrieving revision 1.89
diff -u -p -r1.89 if_var.h
--- if_var.h	10 Jan 2018 23:50:39 -0000	1.89
+++ if_var.h	28 Mar 2018 01:28:03 -0000
@@ -170,6 +170,7 @@ struct ifnet {				/* and the entries */
 	struct	ifqueue **if_ifqs;	/* [I] pointer to an array of sndqs */
 	void	(*if_qstart)(struct ifqueue *);
 	unsigned int if_nifqs;		/* [I] number of output queues */
+	unsigned int if_sndmit;		/* [c] tx mitigation amount */
 
 	struct	ifiqueue if_rcv;	/* rx/input queue */
 	struct	ifiqueue **if_iqs;	/* [I] pointer to the array of iqs */
@@ -279,6 +280,9 @@ do {									\
 #define	IFQ_LEN(ifq)			ifq_len(ifq)
 #define	IFQ_IS_EMPTY(ifq)		ifq_empty(ifq)
 #define	IFQ_SET_MAXLEN(ifq, len)	ifq_set_maxlen(ifq, len)
+
+#define IF_SNDMIT_MIN			1
+#define IF_SNDMIT_DEFAULT		16
 
 /* default interface priorities */
 #define IF_WIRED_DEFAULT_PRIORITY	0
Index: ifq.c
===================================================================
RCS file: /cvs/src/sys/net/ifq.c,v
retrieving revision 1.22
diff -u -p -r1.22 ifq.c
--- ifq.c	25 Jan 2018 14:04:36 -0000	1.22
+++ ifq.c	28 Mar 2018 01:28:03 -0000
@@ -70,9 +70,16 @@ struct priq {
 void	ifq_start_task(void *);
 void	ifq_restart_task(void *);
 void	ifq_barrier_task(void *);
+void	ifq_bundle_task(void *);
 
 #define TASK_ONQUEUE 0x1
 
+static inline void
+ifq_run_start(struct ifqueue *ifq)
+{
+	ifq_serialize(ifq, &ifq->ifq_start);
+}
+
 void
 ifq_serialize(struct ifqueue *ifq, struct task *t)
 {
@@ -114,6 +121,16 @@ ifq_is_serialized(struct ifqueue *ifq)
 }
 
 void
+ifq_start(struct ifqueue *ifq)
+{
+	if (ifq_len(ifq) >= min(ifq->ifq_if->if_sndmit, ifq->ifq_maxlen)) {
+		task_del(ifq->ifq_softnet, &ifq->ifq_bundle);
+		ifq_run_start(ifq);
+	} else
+		task_add(ifq->ifq_softnet, &ifq->ifq_bundle);
+}
+
+void
 ifq_start_task(void *p)
 {
 	struct ifqueue *ifq = p;
@@ -137,11 +154,31 @@ ifq_restart_task(void *p)
 }
 
 void
+ifq_bundle_task(void *p)
+{
+	struct ifqueue *ifq = p;
+
+	ifq_run_start(ifq);
+}
+
+void
 ifq_barrier(struct ifqueue *ifq)
 {
 	struct cond c = COND_INITIALIZER();
 	struct task t = TASK_INITIALIZER(ifq_barrier_task, &c);
 
+	if (!task_del(ifq->ifq_softnet, &ifq->ifq_bundle)) {
+		int netlocked = (rw_status(&netlock) == RW_WRITE);
+
+		if (netlocked) /* XXXSMP breaks atomicity */
+			NET_UNLOCK();
+
+		taskq_barrier(ifq->ifq_softnet);
+
+		if (netlocked)
+			NET_LOCK();
+	}
+
 	if (ifq->ifq_serializer == NULL)
 		return;
 
@@ -166,6 +203,7 @@ void
 ifq_init(struct ifqueue *ifq, struct ifnet *ifp, unsigned int idx)
 {
 	ifq->ifq_if = ifp;
+	ifq->ifq_softnet = net_tq(ifp->if_index);
 	ifq->ifq_softc = NULL;
 
 	mtx_init(&ifq->ifq_mtx, IPL_NET);
@@ -187,6 +225,7 @@ ifq_init(struct ifqueue *ifq, struct ifn
 	mtx_init(&ifq->ifq_task_mtx, IPL_NET);
 	TAILQ_INIT(&ifq->ifq_task_list);
 	ifq->ifq_serializer = NULL;
+	task_set(&ifq->ifq_bundle, ifq_bundle_task, ifq);
 
 	task_set(&ifq->ifq_start, ifq_start_task, ifq);
 	task_set(&ifq->ifq_restart, ifq_restart_task, ifq);
@@ -237,6 +276,8 @@ void
 ifq_destroy(struct ifqueue *ifq)
 {
 	struct mbuf_list ml = MBUF_LIST_INITIALIZER();
+
+	ifq_barrier(ifq); /* ensure nothing is running with the ifq */
 
 	/* don't need to lock because this is the last use of the ifq */
 
Index: ifq.h
===================================================================
RCS file: /cvs/src/sys/net/ifq.h,v
retrieving revision 1.20
diff -u -p -r1.20 ifq.h
--- ifq.h	4 Jan 2018 11:02:57 -0000	1.20
+++ ifq.h	28 Mar 2018 01:28:03 -0000
@@ -25,6 +25,7 @@ struct ifq_ops;
 
 struct ifqueue {
 	struct ifnet		*ifq_if;
+	struct taskq		*ifq_softnet;
 	union {
 		void			*_ifq_softc;
 		/*
@@ -57,6 +58,7 @@ struct ifqueue {
 	struct mutex		 ifq_task_mtx;
 	struct task_list	 ifq_task_list;
 	void			*ifq_serializer;
+	struct task		 ifq_bundle;
 
 	/* work to be serialised */
 	struct task		 ifq_start;
@@ -405,6 +407,7 @@ void		 ifq_attach(struct ifqueue *, cons
 void		 ifq_destroy(struct ifqueue *);
 void		 ifq_add_data(struct ifqueue *, struct if_data *);
 int		 ifq_enqueue(struct ifqueue *, struct mbuf *);
+void		 ifq_start(struct ifqueue *);
 struct mbuf	*ifq_deq_begin(struct ifqueue *);
 void		 ifq_deq_commit(struct ifqueue *, struct mbuf *);
 void		 ifq_deq_rollback(struct ifqueue *, struct mbuf *);
@@ -438,12 +441,6 @@ static inline unsigned int
 ifq_is_oactive(struct ifqueue *ifq)
 {
 	return (ifq->ifq_oactive);
-}
-
-static inline void
-ifq_start(struct ifqueue *ifq)
-{
-	ifq_serialize(ifq, &ifq->ifq_start);
 }
 
 static inline void