Index: share/man/man9/Makefile
===================================================================
RCS file: /cvs/src/share/man/man9/Makefile,v
retrieving revision 1.248
diff -u -p -r1.248 Makefile
--- share/man/man9/Makefile	22 Oct 2015 05:26:06 -0000	1.248
+++ share/man/man9/Makefile	30 Oct 2015 11:31:38 -0000
@@ -269,6 +269,7 @@ MLINKS+=microtime.9 getmicrotime.9 micro
 MLINKS+=ml_init.9 ml_enqueue.9 ml_init.9 ml_dequeue.9 ml_init.9 ml_requeue.9 \
 	ml_init.9 ml_enlist.9 ml_init.9 ml_dechain.9 \
 	ml_init.9 ml_filter.9 ml_init.9 ml_len.9 ml_init.9 ml_empty.9 \
+	ml_init.9 ml_purge.9 \
 	ml_init.9 MBUF_LIST_INITIALIZER.9 ml_init.9 MBUF_LIST_FOREACH.9
 MLINKS+=mountroothook_establish.9 mountroothook_disestablish.9
 MLINKS+=mutex.9 mtx_init.9 mutex.9 mtx_enter.9 mutex.9 mtx_leave.9 \
@@ -277,7 +278,7 @@ MLINKS+=mutex.9 mtx_init.9 mutex.9 mtx_e
 MLINKS+=mutex.9 mtx_enter_try.9
 MLINKS+=mq_init.9 mq_enqueue.9 mq_init.9 mq_dequeue.9 mq_init.9 mq_requeue.9 \
 	mq_init.9 mq_enlist.9 mq_init.9 mq_delist.9 \
-	mq_init.9 mq_dechain.9 mq_init.9 mq_filter.9 \
+	mq_init.9 mq_dechain.9 mq_init.9 mq_filter.9 mq_init.9 mq_purge.9 \
 	mq_init.9 mq_len.9 mq_init.9 mq_empty.9 mq_init.9 mq_drops.9 \
 	mq_init.9 mq_set_maxlen.9 mq_init.9 MBUF_QUEUE_INITIALIZER.9
 MLINKS+=namei.9 vfs_lookup.9 namei.9 vfs_relookup.9 namei.9 NDINIT.9
Index: share/man/man9/ml_init.9
===================================================================
RCS file: /cvs/src/share/man/man9/ml_init.9,v
retrieving revision 1.7
diff -u -p -r1.7 ml_init.9
--- share/man/man9/ml_init.9	22 Oct 2015 05:26:06 -0000	1.7
+++ share/man/man9/ml_init.9	30 Oct 2015 11:31:38 -0000
@@ -53,6 +53,8 @@
 .Fn ml_len "struct mbuf_list *ml"
 .Ft int
 .Fn ml_empty "struct mbuf_list *ml"
+.Ft unsigned int
+.Fn ml_purge "struct mbuf_list *ml"
 .Ft struct mbuf_list
 .Fn MBUF_LIST_INITIALIZER
 .Fn MBUF_LIST_FOREACH "struct mbuf_list *ml" "VARNAME"
@@ -132,6 +134,10 @@ mbuf list.
 Return if the
 .Fa ml
 mbuf list is empty.
+.It Fn ml_purge "struct mbuf_list *ml"
+Free all the mbufs on the
+.Fa ml
+mbuf list.
 .It Fn MBUF_LIST_FOREACH "struct mbuf_list *ml" "VARNAME"
 A convenience macro that can be used to iterate over the contents of the
 .Fa ml
@@ -150,6 +156,7 @@ Note that it is unsafe to modify the lis
 .Fn ml_dechain ,
 .Fn ml_len ,
 .Fn ml_empty ,
+.Fn ml_purge ,
 .Fn MBUF_LIST_INITIALIZER ,
 and
 .Fn MBUF_LIST_FOREACH
@@ -180,5 +187,8 @@ returns the number of mbufs on the list.
 .Pp
 .Fn ml_empty
 return a non-zero value if the list is empty, otherwise 0.
+.Pp
+.Fn ml_purge
+return the number of mbufs that were freed.
 .Sh SEE ALSO
 .Xr mbuf 9
Index: share/man/man9/mq_init.9
===================================================================
RCS file: /cvs/src/share/man/man9/mq_init.9,v
retrieving revision 1.4
diff -u -p -r1.4 mq_init.9
--- share/man/man9/mq_init.9	23 Sep 2015 12:44:35 -0000	1.4
+++ share/man/man9/mq_init.9	30 Oct 2015 11:31:38 -0000
@@ -27,6 +27,7 @@
 .Nm mq_dechain ,
 .Nm mq_len ,
 .Nm mq_empty ,
+.Nm mq_purge ,
 .Nm mq_drops ,
 .Nm mq_set_maxlen ,
 .Nm MBUF_QUEUE_INITIALIZER
@@ -58,6 +59,8 @@
 .Ft int
 .Fn mq_empty "struct mbuf_queue *mq"
 .Ft unsigned int
+.Fn mq_purge "struct mbuf_queue *mq"
+.Ft unsigned int
 .Fn mq_drops "struct mbuf_queue *mq"
 .Ft void
 .Fn mq_set_maxlen "struct mbuf_queue *mq" "unsigned int"
@@ -168,6 +171,10 @@ mbuf queue.
 Return if the
 .Fa mq
 mbuf queue is empty.
+.It Fn mq_purge "struct mbuf_queue *mq"
+Free all the mbufs on the
+.Fa mq
+mbuf queue.
 .It Fn mq_drops "struct mbuf_queue *mq"
 Return how many mbufs were dropped and freed by
 .Xr m_freem 9
@@ -193,6 +200,7 @@ already exist on the queue.
 .Fn mq_dechain ,
 .Fn mq_len ,
 .Fn mq_empty ,
+.Fn mq_purge ,
 .Fn mq_drops ,
 .Fn mq_set_maxlen ,
 and
@@ -237,6 +245,9 @@ length.
 .Fn mq_enlist
 returns the number of mbufs that were dropped from the list if the
 length of the queue exceeded its maximum length.
+.Pp
+.Fn mq_purge
+return the number of mbufs that were freed.
 .Pp
 .Fn mq_drops
 returns the number of mbufs that were freed during
Index: sys/sys/mbuf.h
===================================================================
RCS file: /cvs/src/sys/sys/mbuf.h,v
retrieving revision 1.198
diff -u -p -r1.198 mbuf.h
--- sys/sys/mbuf.h	22 Oct 2015 05:26:06 -0000	1.198
+++ sys/sys/mbuf.h	30 Oct 2015 11:31:38 -0000
@@ -491,6 +491,7 @@ void			ml_enlist(struct mbuf_list *, str
 struct mbuf *		ml_dechain(struct mbuf_list *);
 struct mbuf *		ml_filter(struct mbuf_list *,
 			    int (*)(void *, const struct mbuf *), void *);
+unsigned int		ml_purge(struct mbuf_list *);
 
 #define	ml_len(_ml)		((_ml)->ml_len)
 #define	ml_empty(_ml)		((_ml)->ml_len == 0)
@@ -521,6 +522,7 @@ void			mq_delist(struct mbuf_queue *, st
 struct mbuf *		mq_dechain(struct mbuf_queue *);
 struct mbuf *		mq_filter(struct mbuf_queue *,
 			    int (*)(void *, const struct mbuf *), void *);
+unsigned int		mq_purge(struct mbuf_queue *);
 
 #define	mq_len(_mq)		ml_len(&(_mq)->mq_list)
 #define	mq_empty(_mq)		ml_empty(&(_mq)->mq_list)
Index: sys/kern/uipc_mbuf.c
===================================================================
RCS file: /cvs/src/sys/kern/uipc_mbuf.c,v
retrieving revision 1.208
diff -u -p -r1.208 uipc_mbuf.c
--- sys/kern/uipc_mbuf.c	22 Oct 2015 05:26:06 -0000	1.208
+++ sys/kern/uipc_mbuf.c	30 Oct 2015 11:31:38 -0000
@@ -1351,6 +1351,23 @@ ml_filter(struct mbuf_list *ml,
 	return (matches.ml_head); /* ml_dechain */
 }
 
+unsigned int
+ml_purge(struct mbuf_list *ml)
+{
+	struct mbuf *m, *n;
+	unsigned int len;
+
+	for (m = ml->ml_head; m != NULL; m = n) {
+		n = m->m_nextpkt;
+		m_freem(m);
+	}
+
+	len = ml->ml_len;
+	ml_init(ml);
+
+	return (len);
+}
+
 /*
  * mbuf queues
  */
@@ -1463,4 +1480,14 @@ mq_filter(struct mbuf_queue *mq,
 	mtx_leave(&mq->mq_mtx);
 
 	return (m0);
+}
+
+unsigned int
+mq_purge(struct mbuf_queue *mq)
+{
+	struct mbuf_list ml;
+
+	mq_delist(mq, &ml);
+
+	return (ml_purge(&ml));
 }