diff --git a/sys/alpha/alpha/vm_machdep.c b/sys/alpha/alpha/vm_machdep.c
index 1d7484b83c90..da95586a238f 100644
--- a/sys/alpha/alpha/vm_machdep.c
+++ b/sys/alpha/alpha/vm_machdep.c
@@ -415,6 +415,7 @@ sf_buf_alloc(struct vm_page *m)
 	mtx_lock(&sf_freelist.sf_lock);
 	while ((sf = SLIST_FIRST(&sf_freelist.sf_head)) == NULL) {
 		sf_buf_alloc_want++;
+		mbstat.sf_allocwait++;
 		error = msleep(&sf_freelist, &sf_freelist.sf_lock, PVM|PCATCH,
 		    "sfbufa", 0);
 		sf_buf_alloc_want--;
diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c
index d7c2c68800aa..be625ce0e7fd 100644
--- a/sys/amd64/amd64/vm_machdep.c
+++ b/sys/amd64/amd64/vm_machdep.c
@@ -460,6 +460,7 @@ sf_buf_alloc(struct vm_page *m)
 	mtx_lock(&sf_freelist.sf_lock);
 	while ((sf = SLIST_FIRST(&sf_freelist.sf_head)) == NULL) {
 		sf_buf_alloc_want++;
+		mbstat.sf_allocwait++;
 		error = msleep(&sf_freelist, &sf_freelist.sf_lock, PVM|PCATCH,
 		    "sfbufa", 0);
 		sf_buf_alloc_want--;
diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c
index eebb04e18adf..998780c7fd76 100644
--- a/sys/i386/i386/vm_machdep.c
+++ b/sys/i386/i386/vm_machdep.c
@@ -621,6 +621,7 @@ sf_buf_alloc(struct vm_page *m)
 	}
 	while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) {
 		sf_buf_alloc_want++;
+		mbstat.sf_allocwait++;
 		error = msleep(&sf_buf_freelist, &sf_buf_lock, PVM|PCATCH,
 		    "sfbufa", 0);
 		sf_buf_alloc_want--;
diff --git a/sys/ia64/ia64/vm_machdep.c b/sys/ia64/ia64/vm_machdep.c
index 10c6a619c054..0b72deec7b0b 100644
--- a/sys/ia64/ia64/vm_machdep.c
+++ b/sys/ia64/ia64/vm_machdep.c
@@ -354,6 +354,7 @@ sf_buf_alloc(struct vm_page *m)
 	mtx_lock(&sf_freelist.sf_lock);
 	while ((sf = SLIST_FIRST(&sf_freelist.sf_head)) == NULL) {
 		sf_buf_alloc_want++;
+		mbstat.sf_allocwait++;
 		error = msleep(&sf_freelist, &sf_freelist.sf_lock, PVM|PCATCH,
 		    "sfbufa", 0);
 		sf_buf_alloc_want--;
diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c
index 4c59ae8bbc28..b5c500a15558 100644
--- a/sys/kern/uipc_syscalls.c
+++ b/sys/kern/uipc_syscalls.c
@@ -1866,6 +1866,7 @@ do_sendfile(struct thread *td, struct sendfile_args *uap, int compat)
 				sbunlock(&so->so_snd);
 				goto done;
 			}
+			mbstat.sf_iocnt++;
 		} else
 			VM_OBJECT_UNLOCK(obj);
 		vm_page_unlock_queues();
@@ -1875,6 +1876,7 @@ do_sendfile(struct thread *td, struct sendfile_args *uap, int compat)
 		 * but this wait can be interrupted.
 		 */
 		if ((sf = sf_buf_alloc(pg)) == NULL) {
+			mbstat.sf_allocfail++;
 			vm_page_lock_queues();
 			vm_page_unwire(pg, 0);
 			if (pg->wire_count == 0 && pg->object == NULL)
diff --git a/sys/powerpc/aim/vm_machdep.c b/sys/powerpc/aim/vm_machdep.c
index 5fd9c656c55a..1d582f3bd3a9 100644
--- a/sys/powerpc/aim/vm_machdep.c
+++ b/sys/powerpc/aim/vm_machdep.c
@@ -269,6 +269,7 @@ sf_buf_alloc(struct vm_page *m)
 	mtx_lock(&sf_freelist.sf_lock);
 	while ((sf = SLIST_FIRST(&sf_freelist.sf_head)) == NULL) {
 		sf_buf_alloc_want++;
+		mbstat.sf_allocwait++;
 		error = msleep(&sf_freelist, &sf_freelist.sf_lock, PVM|PCATCH,
 		    "sfbufa", 0);
 		sf_buf_alloc_want--;
diff --git a/sys/powerpc/powerpc/vm_machdep.c b/sys/powerpc/powerpc/vm_machdep.c
index 5fd9c656c55a..1d582f3bd3a9 100644
--- a/sys/powerpc/powerpc/vm_machdep.c
+++ b/sys/powerpc/powerpc/vm_machdep.c
@@ -269,6 +269,7 @@ sf_buf_alloc(struct vm_page *m)
 	mtx_lock(&sf_freelist.sf_lock);
 	while ((sf = SLIST_FIRST(&sf_freelist.sf_head)) == NULL) {
 		sf_buf_alloc_want++;
+		mbstat.sf_allocwait++;
 		error = msleep(&sf_freelist, &sf_freelist.sf_lock, PVM|PCATCH,
 		    "sfbufa", 0);
 		sf_buf_alloc_want--;
diff --git a/sys/sparc64/sparc64/vm_machdep.c b/sys/sparc64/sparc64/vm_machdep.c
index 51a232bc9e8c..2a780749e4e4 100644
--- a/sys/sparc64/sparc64/vm_machdep.c
+++ b/sys/sparc64/sparc64/vm_machdep.c
@@ -396,6 +396,7 @@ sf_buf_alloc(struct vm_page *m)
 	mtx_lock(&sf_freelist.sf_lock);
 	while ((sf = SLIST_FIRST(&sf_freelist.sf_head)) == NULL) {
 		sf_buf_alloc_want++;
+		mbstat.sf_allocwait++;
 		error = msleep(&sf_freelist, &sf_freelist.sf_lock, PVM|PCATCH,
 		    "sfbufa", 0);
 		sf_buf_alloc_want--;
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index eff28cadcd14..d7f61ce85506 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -261,6 +261,10 @@ struct mbstat {
 	u_int	m_clperbuck;	/* number of clusters per "bucket" */
 	/* Number of mbtypes (gives # elems in mbpstat's mb_mbtypes[] array: */
 	short	m_numtypes;
+	/* XXX: Sendfile stats should eventually move to their own struct */
+	u_long	sf_iocnt;	/* times sendfile had to do disk I/O */
+	u_long	sf_allocfail;	/* times sfbuf allocation failed */
+	u_long	sf_allocwait;	/* times sfbuf allocation had to wait */
 };
 
 /*