diff --git a/sys/fs/nfsclient/nfs_clbio.c.append2 b/sys/fs/nfsclient/nfs_clbio.c
--- a/sys/fs/nfsclient/nfs_clbio.c.append2
+++ b/sys/fs/nfsclient/nfs_clbio.c
@@ -1001,12 +1001,24 @@
 	if (uio->uio_resid == 0)
 		return (0);
 
+	/*
+	 * If the file in not mmap()'d, do IO_APPEND writing via a
+	 * synchronous direct write.  This can result in a significant
+	 * performance improvement.
+	 * If the file is mmap()'d, this cannot be done, since there
+	 * is no way to maintain consistency between the file on the
+	 * NFS server and the file's mmap()'d pages.
+	 */
+	NFSLOCKNODE(np);
 	if (vp->v_type == VREG && ((newnfs_directio_enable && (ioflag &
-	    IO_DIRECT)) || (ioflag & IO_APPEND))) {
+	    IO_DIRECT)) || ((ioflag & IO_APPEND) &&
+	    (vp->v_object == NULL || !vm_object_is_active(vp->v_object))))) {
+		NFSUNLOCKNODE(np);
 		if ((ioflag & IO_APPEND) != 0)
 			ioflag |= IO_SYNC;
 		return nfs_directio_write(vp, uio, cred, ioflag);
 	}
+	NFSUNLOCKNODE(np);
 
 	/*
 	 * Maybe this should be above the vnode op call, but so long as
diff --git a/sys/vm/vm_meter.c.append2 b/sys/vm/vm_meter.c
--- a/sys/vm/vm_meter.c.append2
+++ b/sys/vm/vm_meter.c
@@ -142,21 +142,6 @@
     CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_loadavg, "S,loadavg",
     "Machine loadaverage history");
 
-/*
- * This function aims to determine if the object is mapped,
- * specifically, if it is referenced by a vm_map_entry.  Because
- * objects occasionally acquire transient references that do not
- * represent a mapping, the method used here is inexact.  However, it
- * has very low overhead and is good enough for the advisory
- * vm.vmtotal sysctl.
- */
-static bool
-is_object_active(vm_object_t obj)
-{
-
-	return (obj->ref_count > obj->shadow_count);
-}
-
 #if defined(COMPAT_FREEBSD11)
 struct vmtotal11 {
 	int16_t	t_rq;
@@ -268,7 +253,7 @@
 		}
 		total.t_vm += object->size;
 		total.t_rm += object->resident_page_count;
-		if (is_object_active(object)) {
+		if (vm_object_is_active(object)) {
 			total.t_avm += object->size;
 			total.t_arm += object->resident_page_count;
 		}
@@ -276,7 +261,7 @@
 			/* shared object */
 			total.t_vmshr += object->size;
 			total.t_rmshr += object->resident_page_count;
-			if (is_object_active(object)) {
+			if (vm_object_is_active(object)) {
 				total.t_avmshr += object->size;
 				total.t_armshr += object->resident_page_count;
 			}
diff --git a/sys/vm/vm_object.h.append2 b/sys/vm/vm_object.h
--- a/sys/vm/vm_object.h.append2
+++ b/sys/vm/vm_object.h
@@ -391,6 +391,7 @@
 void vm_object_unwire(vm_object_t object, vm_ooffset_t offset,
     vm_size_t length, uint8_t queue);
 struct vnode *vm_object_vnode(vm_object_t object);
+bool vm_object_is_active(vm_object_t obj);
 #endif				/* _KERNEL */
 
 #endif				/* _VM_OBJECT_ */
diff --git a/sys/vm/vm_object.c.append2 b/sys/vm/vm_object.c
--- a/sys/vm/vm_object.c.append2
+++ b/sys/vm/vm_object.c
@@ -2498,6 +2498,21 @@
 	(void)blockcount_sleep(&obj->busy, NULL, wmesg, PVM);
 }
 
+/*
+ * This function aims to determine if the object is mapped,
+ * specifically, if it is referenced by a vm_map_entry.  Because
+ * objects occasionally acquire transient references that do not
+ * represent a mapping, the method used here is inexact.  However, it
+ * has very low overhead and is good enough for the advisory
+ * vm.vmtotal sysctl.
+ */
+bool
+vm_object_is_active(vm_object_t obj)
+{
+
+	return (obj->ref_count > obj->shadow_count);
+}
+
 static int
 vm_object_list_handler(struct sysctl_req *req, bool swap_only)
 {