Index: share/man/man9/Makefile
===================================================================
--- share/man/man9/Makefile
+++ share/man/man9/Makefile
@@ -1712,6 +1712,7 @@
 	sysctl.9 SYSCTL_ADD_INT.9 \
 	sysctl.9 SYSCTL_ADD_LONG.9 \
 	sysctl.9 SYSCTL_ADD_NODE.9 \
+	sysctl.9 SYSCTL_ADD_NODE_WITH_LABEL.9 \
 	sysctl.9 SYSCTL_ADD_OPAQUE.9 \
 	sysctl.9 SYSCTL_ADD_PROC.9 \
 	sysctl.9 SYSCTL_ADD_QUAD.9 \
@@ -1735,8 +1736,10 @@
 	sysctl.9 SYSCTL_NODE_CHILDREN.9 \
 	sysctl.9 SYSCTL_PARENT.9 \
 	sysctl.9 SYSCTL_INT.9 \
+	sysctl.9 SYSCTL_INT_WITH_LABEL.9 \
 	sysctl.9 SYSCTL_LONG.9 \
 	sysctl.9 SYSCTL_NODE.9 \
+	sysctl.9 SYSCTL_NODE_WITH_LABEL.9 \
 	sysctl.9 SYSCTL_OPAQUE.9 \
 	sysctl.9 SYSCTL_PROC.9 \
 	sysctl.9 SYSCTL_QUAD.9 \
Index: share/man/man9/sysctl.9
===================================================================
--- share/man/man9/sysctl.9
+++ share/man/man9/sysctl.9
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 23, 2015
+.Dd December 13, 2016
 .Dt SYSCTL 9
 .Os
 .Sh NAME
@@ -33,6 +33,7 @@
 .Nm SYSCTL_ADD_INT ,
 .Nm SYSCTL_ADD_LONG ,
 .Nm SYSCTL_ADD_NODE ,
+.Nm SYSCTL_ADD_NODE_WITH_LABEL ,
 .Nm SYSCTL_ADD_OPAQUE ,
 .Nm SYSCTL_ADD_PROC ,
 .Nm SYSCTL_ADD_QUAD ,
@@ -56,8 +57,10 @@
 .Nm SYSCTL_NODE_CHILDREN ,
 .Nm SYSCTL_PARENT ,
 .Nm SYSCTL_INT ,
+.Nm SYSCTL_INT_WITH_LABEL ,
 .Nm SYSCTL_LONG ,
 .Nm SYSCTL_NODE ,
+.Nm SYSCTL_NODE_WITH_LABEL ,
 .Nm SYSCTL_OPAQUE ,
 .Nm SYSCTL_PROC ,
 .Nm SYSCTL_QUAD ,
@@ -112,6 +115,17 @@
 .Fa "const char *descr"
 .Fc
 .Ft struct sysctl_oid *
+.Fo SYSCTL_ADD_NODE_WITH_LABEL
+.Fa "struct sysctl_ctx_list *ctx"
+.Fa "struct sysctl_oid_list *parent"
+.Fa "int number"
+.Fa "const char *name"
+.Fa "int ctlflags"
+.Fa "int (*handler)(SYSCTL_HANDLER_ARGS)"
+.Fa "const char *descr"
+.Fa "const char *label"
+.Fc
+.Ft struct sysctl_oid *
 .Fo SYSCTL_ADD_OPAQUE
 .Fa "struct sysctl_ctx_list *ctx"
 .Fa "struct sysctl_oid_list *parent"
@@ -324,8 +338,10 @@
 .Fa "struct sysctl_oid *oid"
 .Fc
 .Fn SYSCTL_INT parent number name ctlflags ptr val descr
+.Fn SYSCTL_INT_WITH_LABEL parent number name ctlflags ptr val descr label
 .Fn SYSCTL_LONG parent number name ctlflags ptr val descr
 .Fn SYSCTL_NODE parent number name ctlflags handler descr
+.Fn SYSCTL_NODE_WITH_LABEL parent number name ctlflags handler descr label
 .Fn SYSCTL_OPAQUE parent number name ctlflags ptr len format descr
 .Fn SYSCTL_PROC parent number name ctlflags arg1 arg2 handler format descr
 .Fn SYSCTL_QUAD parent number name ctlflags ptr val descr
@@ -459,6 +475,18 @@
 .El
 .It Fa descr
 A pointer to a textual description of the OID.
+.It Fa label
+A pointer to an aggregation label for this component of the OID.
+To make it easier to export sysctl data to monitoring systems that
+support aggregations through labels (e.g., Prometheus),
+this argument can be used to attach a label name to an OID.
+The label acts as a hint that this component's name should not be part
+of the metric's name,
+but attached to the metric as a label instead.
+.Pp
+Labels should only be applied to siblings that are structurally similar
+and encode the same type of value,
+as aggregation is of no use otherwise.
 .El
 .Sh CREATING ROOT NODES
 Sysctl MIBs or OIDs are created in a hierarchical tree.
@@ -517,8 +545,10 @@
 .Sh CREATING A STATIC SYSCTL
 Static sysctls are declared using one of the
 .Fn SYSCTL_INT ,
+.Fn SYSCTL_INT_WITH_LABEL ,
 .Fn SYSCTL_LONG ,
 .Fn SYSCTL_NODE ,
+.Fn SYSCTL_NODE_WITH_LABEL ,
 .Fn SYSCTL_OPAQUE ,
 .Fn SYSCTL_PROC ,
 .Fn SYSCTL_QUAD ,
@@ -543,6 +573,7 @@
 .Fn SYSCTL_ADD_INT ,
 .Fn SYSCTL_ADD_LONG ,
 .Fn SYSCTL_ADD_NODE ,
+.Fn SYSCTL_ADD_NODE_WITH_LABEL ,
 .Fn SYSCTL_ADD_OPAQUE ,
 .Fn SYSCTL_ADD_PROC ,
 .Fn SYSCTL_ADD_QUAD ,
Index: share/man/man9/sysctl_add_oid.9
===================================================================
--- share/man/man9/sysctl_add_oid.9
+++ share/man/man9/sysctl_add_oid.9
@@ -27,7 +27,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 6, 2015
+.Dd December 13, 2016
 .Dt SYSCTL_ADD_OID 9
 .Os
 .Sh NAME
@@ -51,6 +51,7 @@
 .Fa "int (*handler) (SYSCTL_HANDLER_ARGS)"
 .Fa "const char *format"
 .Fa "const char *descr"
+.Fa "const char *label"
 .Fc
 .Ft int
 .Fo sysctl_move_oid
Index: sys/cam/ata/ata_da.c
===================================================================
--- sys/cam/ata/ata_da.c
+++ sys/cam/ata/ata_da.c
@@ -1394,9 +1394,9 @@
 
 	sysctl_ctx_init(&softc->sysctl_ctx);
 	softc->flags |= ADA_FLAG_SCTX_INIT;
-	softc->sysctl_tree = SYSCTL_ADD_NODE(&softc->sysctl_ctx,
+	softc->sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&softc->sysctl_ctx,
 		SYSCTL_STATIC_CHILDREN(_kern_cam_ada), OID_AUTO, tmpstr2,
-		CTLFLAG_RD, 0, tmpstr);
+		CTLFLAG_RD, 0, tmpstr, "device_index");
 	if (softc->sysctl_tree == NULL) {
 		printf("adasysctlinit: unable to allocate sysctl tree\n");
 		cam_periph_release(periph);
Index: sys/cam/ata/ata_pmp.c
===================================================================
--- sys/cam/ata/ata_pmp.c
+++ sys/cam/ata/ata_pmp.c
@@ -350,9 +350,9 @@
 
 	sysctl_ctx_init(&softc->sysctl_ctx);
 	softc->flags |= PMP_FLAG_SCTX_INIT;
-	softc->sysctl_tree = SYSCTL_ADD_NODE(&softc->sysctl_ctx,
+	softc->sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&softc->sysctl_ctx,
 		SYSCTL_STATIC_CHILDREN(_kern_cam_pmp), OID_AUTO, tmpstr2,
-		CTLFLAG_RD, 0, tmpstr);
+		CTLFLAG_RD, 0, tmpstr, "device_index");
 	if (softc->sysctl_tree == NULL) {
 		printf("pmpsysctlinit: unable to allocate sysctl tree\n");
 		cam_periph_release(periph);
Index: sys/cam/nvme/nvme_da.c
===================================================================
--- sys/cam/nvme/nvme_da.c
+++ sys/cam/nvme/nvme_da.c
@@ -608,9 +608,9 @@
 
 	sysctl_ctx_init(&softc->sysctl_ctx);
 	softc->flags |= NDA_FLAG_SCTX_INIT;
-	softc->sysctl_tree = SYSCTL_ADD_NODE(&softc->sysctl_ctx,
+	softc->sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&softc->sysctl_ctx,
 		SYSCTL_STATIC_CHILDREN(_kern_cam_nda), OID_AUTO, tmpstr2,
-		CTLFLAG_RD, 0, tmpstr);
+		CTLFLAG_RD, 0, tmpstr, "device_index");
 	if (softc->sysctl_tree == NULL) {
 		printf("ndasysctlinit: unable to allocate sysctl tree\n");
 		cam_periph_release(periph);
Index: sys/cam/scsi/scsi_cd.c
===================================================================
--- sys/cam/scsi/scsi_cd.c
+++ sys/cam/scsi/scsi_cd.c
@@ -481,9 +481,9 @@
 
 	sysctl_ctx_init(&softc->sysctl_ctx);
 	softc->flags |= CD_FLAG_SCTX_INIT;
-	softc->sysctl_tree = SYSCTL_ADD_NODE(&softc->sysctl_ctx,
+	softc->sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&softc->sysctl_ctx,
 		SYSCTL_STATIC_CHILDREN(_kern_cam_cd), OID_AUTO,
-		tmpstr2, CTLFLAG_RD, 0, tmpstr);
+		tmpstr2, CTLFLAG_RD, 0, tmpstr, "device_index");
 
 	if (softc->sysctl_tree == NULL) {
 		printf("cdsysctlinit: unable to allocate sysctl tree\n");
Index: sys/cam/scsi/scsi_da.c
===================================================================
--- sys/cam/scsi/scsi_da.c
+++ sys/cam/scsi/scsi_da.c
@@ -1924,9 +1924,9 @@
 
 	sysctl_ctx_init(&softc->sysctl_ctx);
 	softc->flags |= DA_FLAG_SCTX_INIT;
-	softc->sysctl_tree = SYSCTL_ADD_NODE(&softc->sysctl_ctx,
+	softc->sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&softc->sysctl_ctx,
 		SYSCTL_STATIC_CHILDREN(_kern_cam_da), OID_AUTO, tmpstr2,
-		CTLFLAG_RD, 0, tmpstr);
+		CTLFLAG_RD, 0, tmpstr, "device_index");
 	if (softc->sysctl_tree == NULL) {
 		printf("dasysctlinit: unable to allocate sysctl tree\n");
 		cam_periph_release(periph);
Index: sys/cam/scsi/scsi_sa.c
===================================================================
--- sys/cam/scsi/scsi_sa.c
+++ sys/cam/scsi/scsi_sa.c
@@ -2308,9 +2308,9 @@
 
 	sysctl_ctx_init(&softc->sysctl_ctx);
 	softc->flags |= SA_FLAG_SCTX_INIT;
-	softc->sysctl_tree = SYSCTL_ADD_NODE(&softc->sysctl_ctx,
+	softc->sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&softc->sysctl_ctx,
 	    SYSCTL_STATIC_CHILDREN(_kern_cam_sa), OID_AUTO, tmpstr2,
-                    CTLFLAG_RD, 0, tmpstr);
+	    CTLFLAG_RD, 0, tmpstr, "device_index");
 	if (softc->sysctl_tree == NULL)
 		goto bailout;
 
Index: sys/dev/acpica/acpi_thermal.c
===================================================================
--- sys/dev/acpica/acpi_thermal.c
+++ sys/dev/acpica/acpi_thermal.c
@@ -258,9 +258,9 @@
     }
     sysctl_ctx_init(&sc->tz_sysctl_ctx);
     sprintf(oidname, "tz%d", device_get_unit(dev));
-    sc->tz_sysctl_tree = SYSCTL_ADD_NODE(&sc->tz_sysctl_ctx,
-					 SYSCTL_CHILDREN(acpi_tz_sysctl_tree),
-					 OID_AUTO, oidname, CTLFLAG_RD, 0, "");
+    sc->tz_sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&sc->tz_sysctl_ctx,
+			 SYSCTL_CHILDREN(acpi_tz_sysctl_tree),
+			 OID_AUTO, oidname, CTLFLAG_RD, 0, "", "thermal_zone");
     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
 		    OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD,
 		    &sc->tz_temperature, 0, sysctl_handle_int,
Index: sys/kern/kern_et.c
===================================================================
--- sys/kern/kern_et.c
+++ sys/kern/kern_et.c
@@ -66,9 +66,9 @@
 		}
 	}
 	KASSERT(et->et_start, ("et_register: timer has no start function"));
-	et->et_sysctl = SYSCTL_ADD_NODE(NULL,
+	et->et_sysctl = SYSCTL_ADD_NODE_WITH_LABEL(NULL,
 	    SYSCTL_STATIC_CHILDREN(_kern_eventtimer_et), OID_AUTO, et->et_name,
-	    CTLFLAG_RW, 0, "event timer description");
+	    CTLFLAG_RW, 0, "event timer description", "eventtimer");
 	SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
 	    "flags", CTLFLAG_RD, &(et->et_flags), 0,
 	    "Event timer capabilities");
Index: sys/kern/kern_sysctl.c
===================================================================
--- sys/kern/kern_sysctl.c
+++ sys/kern/kern_sysctl.c
@@ -678,6 +678,9 @@
 			if (oidp->oid_descr)
 				free(__DECONST(char *, oidp->oid_descr),
 				    M_SYSCTLOID);
+			if (oidp->oid_label)
+				free(__DECONST(char *, oidp->oid_label),
+				    M_SYSCTLOID);
 			free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID);
 			free(oidp, M_SYSCTLOID);
 		}
@@ -691,7 +694,8 @@
 struct sysctl_oid *
 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
 	int number, const char *name, int kind, void *arg1, intmax_t arg2,
-	int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
+	int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr,
+	const char *label)
 {
 	struct sysctl_oid *oidp;
 
@@ -728,6 +732,8 @@
 	oidp->oid_fmt = fmt;
 	if (descr != NULL)
 		oidp->oid_descr = strdup(descr, M_SYSCTLOID);
+	if (label != NULL)
+		oidp->oid_label = strdup(label, M_SYSCTLOID);
 	/* Update the context, if used */
 	if (clist != NULL)
 		sysctl_ctx_entry_add(clist, oidp);
@@ -1176,6 +1182,31 @@
 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
     sysctl_sysctl_oiddescr, "");
 
+static int
+sysctl_sysctl_oidlabel(SYSCTL_HANDLER_ARGS)
+{
+	struct sysctl_oid *oid;
+	struct rm_priotracker tracker;
+	int error;
+
+	SYSCTL_RLOCK(&tracker);
+	error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
+	if (error)
+		goto out;
+
+	if (oid->oid_label == NULL) {
+		error = ENOENT;
+		goto out;
+	}
+	error = SYSCTL_OUT(req, oid->oid_label, strlen(oid->oid_label) + 1);
+ out:
+	SYSCTL_RUNLOCK(&tracker);
+	return (error);
+}
+
+static SYSCTL_NODE(_sysctl, 6, oidlabel,
+    CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_oidlabel, "");
+
 /*
  * Default "handler" functions.
  */
Index: sys/kern/kern_tc.c
===================================================================
--- sys/kern/kern_tc.c
+++ sys/kern/kern_tc.c
@@ -1218,9 +1218,9 @@
 	/*
 	 * Set up sysctl tree for this counter.
 	 */
-	tc_root = SYSCTL_ADD_NODE(NULL,
+	tc_root = SYSCTL_ADD_NODE_WITH_LABEL(NULL,
 	    SYSCTL_STATIC_CHILDREN(_kern_timecounter_tc), OID_AUTO, tc->tc_name,
-	    CTLFLAG_RW, 0, "timecounter description");
+	    CTLFLAG_RW, 0, "timecounter description", "timecounter");
 	SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO,
 	    "mask", CTLFLAG_RD, &(tc->tc_counter_mask), 0,
 	    "mask for implemented bits");
Index: sys/kern/subr_bus.c
===================================================================
--- sys/kern/subr_bus.c
+++ sys/kern/subr_bus.c
@@ -288,10 +288,10 @@
 		return;
 	devclass_sysctl_init(dc);
 	sysctl_ctx_init(&dev->sysctl_ctx);
-	dev->sysctl_tree = SYSCTL_ADD_NODE(&dev->sysctl_ctx,
+	dev->sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&dev->sysctl_ctx,
 	    SYSCTL_CHILDREN(dc->sysctl_tree), OID_AUTO,
 	    dev->nameunit + strlen(dc->name),
-	    CTLFLAG_RD, NULL, "");
+	    CTLFLAG_RD, NULL, "", "device_index");
 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
 	    OID_AUTO, "%desc", CTLTYPE_STRING | CTLFLAG_RD,
 	    dev, DEVICE_SYSCTL_DESC, device_sysctl_handler, "A",
Index: sys/sys/sysctl.h
===================================================================
--- sys/sys/sysctl.h
+++ sys/sys/sysctl.h
@@ -188,6 +188,7 @@
 	int		 oid_refcnt;
 	u_int		 oid_running;
 	const char	*oid_descr;
+	const char	*oid_label;
 };
 
 #define	SYSCTL_IN(r, p, l)	(r->newfunc)(r, p, l)
@@ -252,7 +253,7 @@
 #endif
 
 /* This macro is only for internal use */
-#define	SYSCTL_OID_RAW(id, parent_child_head, nbr, name, kind, a1, a2, handler, fmt, descr) \
+#define	SYSCTL_OID_RAW(id, parent_child_head, nbr, name, kind, a1, a2, handler, fmt, descr, label) \
 	struct sysctl_oid id = {					\
 		.oid_parent = (parent_child_head),			\
 		.oid_children = SLIST_HEAD_INITIALIZER(&id.oid_children), \
@@ -263,46 +264,58 @@
 		.oid_name = (name),					\
 		.oid_handler = (handler),				\
 		.oid_fmt = (fmt),					\
-		.oid_descr = __DESCR(descr)				\
+		.oid_descr = __DESCR(descr),				\
+		.oid_label = (label),					\
 	};								\
 	DATA_SET(sysctl_set, id)
 
 /* This constructs a static "raw" MIB oid. */
 #define	SYSCTL_OID(parent, nbr, name, kind, a1, a2, handler, fmt, descr) \
-    static SYSCTL_OID_RAW(sysctl__##parent##_##name, \
-	SYSCTL_CHILDREN(&sysctl__##parent), \
-	nbr, #name, kind, a1, a2, handler, fmt, descr)
+	SYSCTL_OID_WITH_LABEL(parent, nbr, name, kind, a1, a2,		\
+	    handler, fmt, descr, NULL)
+
+#define	SYSCTL_OID_WITH_LABEL(parent, nbr, name, kind, a1, a2, handler, fmt, descr, label) \
+    static SYSCTL_OID_RAW(sysctl__##parent##_##name,			\
+	SYSCTL_CHILDREN(&sysctl__##parent),				\
+	nbr, #name, kind, a1, a2, handler, fmt, descr, label)
 
 /* This constructs a global "raw" MIB oid. */
-#define	SYSCTL_OID_GLOBAL(parent, nbr, name, kind, a1, a2, handler, fmt, descr) \
+#define	SYSCTL_OID_GLOBAL(parent, nbr, name, kind, a1, a2, handler, fmt, descr, label) \
     SYSCTL_OID_RAW(sysctl__##parent##_##name, \
 	SYSCTL_CHILDREN(&sysctl__##parent),	\
-	nbr, #name, kind, a1, a2, handler, fmt, descr)
+	nbr, #name, kind, a1, a2, handler, fmt, descr, label)
 
 #define	SYSCTL_ADD_OID(ctx, parent, nbr, name, kind, a1, a2, handler, fmt, descr) \
-	sysctl_add_oid(ctx, parent, nbr, name, kind, a1, a2, handler, fmt, __DESCR(descr))
+	sysctl_add_oid(ctx, parent, nbr, name, kind, a1, a2, handler, fmt, __DESCR(descr), NULL)
 
 /* This constructs a root node from which other nodes can hang. */
 #define	SYSCTL_ROOT_NODE(nbr, name, access, handler, descr)	\
 	SYSCTL_OID_RAW(sysctl___##name, &sysctl__children,	\
 	    nbr, #name, CTLTYPE_NODE|(access), NULL, 0,		\
-	    handler, "N", descr);				\
+	    handler, "N", descr, NULL);				\
 	CTASSERT(((access) & CTLTYPE) == 0 ||			\
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_NODE)
 
 /* This constructs a node from which other oids can hang. */
-#define	SYSCTL_NODE(parent, nbr, name, access, handler, descr)		\
+#define	SYSCTL_NODE(parent, nbr, name, access, handler, descr) \
+	SYSCTL_NODE_WITH_LABEL(parent, nbr, name, access, handler, descr, NULL)
+
+#define	SYSCTL_NODE_WITH_LABEL(parent, nbr, name, access, handler, descr, label) \
 	SYSCTL_OID_GLOBAL(parent, nbr, name, CTLTYPE_NODE|(access),	\
-	    NULL, 0, handler, "N", descr);				\
+	    NULL, 0, handler, "N", descr, label);			\
 	CTASSERT(((access) & CTLTYPE) == 0 ||				\
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_NODE)
 
 #define	SYSCTL_ADD_NODE(ctx, parent, nbr, name, access, handler, descr)	\
+	SYSCTL_ADD_NODE_WITH_LABEL(ctx, parent, nbr, name, access, \
+	    handler, descr, NULL)
+
+#define	SYSCTL_ADD_NODE_WITH_LABEL(ctx, parent, nbr, name, access, handler, descr, label) \
 ({									\
 	CTASSERT(((access) & CTLTYPE) == 0 ||				\
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_NODE);	\
 	sysctl_add_oid(ctx, parent, nbr, name, CTLTYPE_NODE|(access),	\
-	    NULL, 0, handler, "N", __DESCR(descr));			\
+	    NULL, 0, handler, "N", __DESCR(descr), label);		\
 })
 
 #define	SYSCTL_ADD_ROOT_NODE(ctx, nbr, name, access, handler, descr)	\
@@ -311,7 +324,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_NODE);	\
 	sysctl_add_oid(ctx, &sysctl__children, nbr, name,		\
 	    CTLTYPE_NODE|(access),					\
-	    NULL, 0, handler, "N", __DESCR(descr));			\
+	    NULL, 0, handler, "N", __DESCR(descr), NULL);		\
 })
 
 /* Oid for a string.  len can be 0 to indicate '\0' termination. */
@@ -327,7 +340,8 @@
 	CTASSERT(((access) & CTLTYPE) == 0 ||				\
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_STRING);	\
 	sysctl_add_oid(ctx, parent, nbr, name, CTLTYPE_STRING|(access),	\
-	    __arg, len, sysctl_handle_string, "A", __DESCR(descr));	\
+	    __arg, len, sysctl_handle_string, "A", __DESCR(descr),	\
+	    NULL); \
 })
 
 /* Oid for a bool.  If ptr is NULL, val is returned. */
@@ -345,7 +359,8 @@
 	CTASSERT(((access) & CTLTYPE) == 0);				\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_U8 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_bool, "CU", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_bool, "CU", __DESCR(descr),	\
+	    NULL);							\
 })
 
 /* Oid for a signed 8-bit int.  If ptr is NULL, val is returned. */
@@ -365,7 +380,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_S8);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_S8 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_8, "C", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_8, "C", __DESCR(descr), NULL);	\
 })
 
 /* Oid for an unsigned 8-bit int.  If ptr is NULL, val is returned. */
@@ -385,7 +400,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_U8);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_U8 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_8, "CU", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_8, "CU", __DESCR(descr), NULL);	\
 })
 
 /* Oid for a signed 16-bit int.  If ptr is NULL, val is returned. */
@@ -405,7 +420,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_S16);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_S16 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_16, "S", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_16, "S", __DESCR(descr), NULL);	\
 })
 
 /* Oid for an unsigned 16-bit int.  If ptr is NULL, val is returned. */
@@ -425,7 +440,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_U16);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_U16 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_16, "SU", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_16, "SU", __DESCR(descr), NULL);	\
 })
 
 /* Oid for a signed 32-bit int.  If ptr is NULL, val is returned. */
@@ -445,7 +460,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_S32);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_S32 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_32, "I", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_32, "I", __DESCR(descr), NULL);	\
 })
 
 /* Oid for an unsigned 32-bit int.  If ptr is NULL, val is returned. */
@@ -465,7 +480,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_U32);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_U32 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_32, "IU", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_32, "IU", __DESCR(descr), NULL);	\
 })
 
 /* Oid for a signed 64-bit int.  If ptr is NULL, val is returned. */
@@ -485,7 +500,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_S64);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_S64 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_64, "Q", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_64, "Q", __DESCR(descr), NULL);	\
 })
 
 /* Oid for an unsigned 64-bit int.  If ptr is NULL, val is returned. */
@@ -505,16 +520,19 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_U64);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_U64 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_64, "QU", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_64, "QU", __DESCR(descr), NULL);	\
 })
 
 /* Oid for an int.  If ptr is SYSCTL_NULL_INT_PTR, val is returned. */
 #define	SYSCTL_NULL_INT_PTR ((int *)NULL)
-#define	SYSCTL_INT(parent, nbr, name, access, ptr, val, descr)	\
-	SYSCTL_OID(parent, nbr, name,				\
-	    CTLTYPE_INT | CTLFLAG_MPSAFE | (access),		\
-	    ptr, val, sysctl_handle_int, "I", descr);		\
-	CTASSERT((((access) & CTLTYPE) == 0 ||			\
+#define	SYSCTL_INT(parent, nbr, name, access, ptr, val, descr) \
+	SYSCTL_INT_WITH_LABEL(parent, nbr, name, access, ptr, val, descr, NULL)
+
+#define	SYSCTL_INT_WITH_LABEL(parent, nbr, name, access, ptr, val, descr, label) \
+	SYSCTL_OID_WITH_LABEL(parent, nbr, name,			\
+	    CTLTYPE_INT | CTLFLAG_MPSAFE | (access),			\
+	    ptr, val, sysctl_handle_int, "I", descr, label);		\
+	CTASSERT((((access) & CTLTYPE) == 0 ||				\
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_INT) && \
 	    sizeof(int) == sizeof(*(ptr)))
 
@@ -525,7 +543,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_INT);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_INT | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_int, "I", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_int, "I", __DESCR(descr), NULL);	\
 })
 
 /* Oid for an unsigned int.  If ptr is NULL, val is returned. */
@@ -545,7 +563,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_UINT);	\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_UINT | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, val, sysctl_handle_int, "IU", __DESCR(descr));	\
+	    __ptr, val, sysctl_handle_int, "IU", __DESCR(descr), NULL);	\
 })
 
 /* Oid for a long.  The pointer must be non NULL. */
@@ -565,7 +583,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_LONG);	\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_LONG | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, 0, sysctl_handle_long, "L", __DESCR(descr));		\
+	    __ptr, 0, sysctl_handle_long, "L", __DESCR(descr), NULL);	\
 })
 
 /* Oid for an unsigned long.  The pointer must be non NULL. */
@@ -585,7 +603,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_ULONG);	\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_ULONG | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, 0, sysctl_handle_long, "LU", __DESCR(descr));	\
+	    __ptr, 0, sysctl_handle_long, "LU", __DESCR(descr), NULL);	\
 })
 
 /* Oid for a quad.  The pointer must be non NULL. */
@@ -605,7 +623,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_S64);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_S64 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, 0, sysctl_handle_64, "Q", __DESCR(descr));		\
+	    __ptr, 0, sysctl_handle_64, "Q", __DESCR(descr), NULL);	\
 })
 
 #define	SYSCTL_NULL_UQUAD_PTR ((uint64_t *)NULL)
@@ -624,7 +642,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_U64);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_U64 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, 0, sysctl_handle_64, "QU", __DESCR(descr));		\
+	    __ptr, 0, sysctl_handle_64, "QU", __DESCR(descr), NULL);	\
 })
 
 /* Oid for a CPU dependent variable */
@@ -638,12 +656,12 @@
 		__ret = sysctl_add_oid(ctx, parent, nbr, name,		\
 		    CTLTYPE_U64 | CTLFLAG_MPSAFE | (access),		\
 		    (ptr), 0, sysctl_handle_64, "QU",			\
-		    __DESCR(descr));					\
+		    __DESCR(descr), NULL);				\
 	} else {							\
 		__ret = sysctl_add_oid(ctx, parent, nbr, name,		\
 		    CTLTYPE_UINT | CTLFLAG_MPSAFE | (access),		\
 		    (ptr), 0, sysctl_handle_int, "IU",			\
-		    __DESCR(descr));					\
+		    __DESCR(descr), NULL);				\
 	}								\
 	__ret;								\
 })
@@ -665,7 +683,8 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_U64);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_U64 | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, 0, sysctl_handle_counter_u64, "QU", __DESCR(descr));	\
+	    __ptr, 0, sysctl_handle_counter_u64, "QU", __DESCR(descr),	\
+	    NULL);							\
 })
 
 /* Oid for an array of counter(9)s.  The pointer and length must be non zero. */
@@ -687,7 +706,7 @@
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | (access),			\
 	    __ptr, len, sysctl_handle_counter_u64_array, "S",		\
-	    __DESCR(descr));						\
+	    __DESCR(descr), NULL);					\
 })
 
 /* Oid for an opaque object.  Specified by a pointer and a length. */
@@ -702,7 +721,7 @@
 	CTASSERT(((access) & CTLTYPE) == 0 ||				\
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_OPAQUE);	\
 	sysctl_add_oid(ctx, parent, nbr, name, CTLTYPE_OPAQUE|(access),	\
-	    ptr, len, sysctl_handle_opaque, fmt, __DESCR(descr));	\
+	    ptr, len, sysctl_handle_opaque, fmt, __DESCR(descr), NULL);	\
 })
 
 /* Oid for a struct.  Specified by a pointer and a type. */
@@ -719,7 +738,7 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_OPAQUE);	\
 	sysctl_add_oid(ctx, parent, nbr, name, CTLTYPE_OPAQUE|(access),	\
 	    (ptr), sizeof(struct type),					\
-	    sysctl_handle_opaque, "S," #type, __DESCR(descr));		\
+	    sysctl_handle_opaque, "S," #type, __DESCR(descr), NULL);	\
 })
 
 /* Oid for a procedure.  Specified by a pointer and an arg. */
@@ -732,7 +751,7 @@
 ({									\
 	CTASSERT(((access) & CTLTYPE) != 0);				\
 	sysctl_add_oid(ctx, parent, nbr, name, (access),		\
-	    (ptr), (arg), (handler), (fmt), __DESCR(descr));		\
+	    (ptr), (arg), (handler), (fmt), __DESCR(descr), NULL);	\
 })
 
 /* Oid to handle limits on uma(9) zone specified by pointer. */
@@ -750,7 +769,8 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_INT);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_INT | CTLFLAG_MPSAFE | (access),			\
-	    __ptr, 0, sysctl_handle_uma_zone_max, "I", __DESCR(descr));	\
+	    __ptr, 0, sysctl_handle_uma_zone_max, "I", __DESCR(descr),	\
+	    NULL);							\
 })
 
 /* Oid to obtain current use of uma(9) zone specified by pointer. */
@@ -768,7 +788,8 @@
 	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_INT);		\
 	sysctl_add_oid(ctx, parent, nbr, name,				\
 	    CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RD | (access),	\
-	    __ptr, 0, sysctl_handle_uma_zone_cur, "I", __DESCR(descr));	\
+	    __ptr, 0, sysctl_handle_uma_zone_cur, "I", __DESCR(descr),	\
+	    NULL);							\
 })
 
 /*
@@ -776,8 +797,8 @@
  * kernel features.
  */
 #define	FEATURE(name, desc)						\
-	SYSCTL_INT(_kern_features, OID_AUTO, name, CTLFLAG_RD | CTLFLAG_CAPRD, \
-	    SYSCTL_NULL_INT_PTR, 1, desc)
+	SYSCTL_INT_WITH_LABEL(_kern_features, OID_AUTO, name,		\
+	    CTLFLAG_RD | CTLFLAG_CAPRD, SYSCTL_NULL_INT_PTR, 1, desc, "feature")
 
 #endif /* _KERNEL */
 
@@ -993,7 +1014,7 @@
 struct sysctl_oid *sysctl_add_oid(struct sysctl_ctx_list *clist,
 	    struct sysctl_oid_list *parent, int nbr, const char *name, int kind,
 	    void *arg1, intmax_t arg2, int (*handler)(SYSCTL_HANDLER_ARGS),
-	    const char *fmt, const char *descr);
+	    const char *fmt, const char *descr, const char *label);
 int	sysctl_remove_name(struct sysctl_oid *parent, const char *name, int del,
 	    int recurse);
 void	sysctl_rename_oid(struct sysctl_oid *oidp, const char *name);