Index: sys/powerpc/aim/mmu_oea64.c
===================================================================
--- sys/powerpc/aim/mmu_oea64.c
+++ sys/powerpc/aim/mmu_oea64.c
@@ -319,12 +319,7 @@
 /* MD page flag indicating that the page is a superpage. */
 #define	MDPG_ATTR_SP		0x40000000
 
-static SYSCTL_NODE(_vm, OID_AUTO, pmap, CTLFLAG_RD, 0,
-    "VM/pmap parameters");
-
-static int superpages_enabled = 0;
-SYSCTL_INT(_vm_pmap, OID_AUTO, superpages_enabled, CTLFLAG_RDTUN,
-    &superpages_enabled, 0, "Enable support for transparent superpages");
+SYSCTL_DECL(_vm_pmap);
 
 static SYSCTL_NODE(_vm_pmap, OID_AUTO, sp, CTLFLAG_RD, 0,
     "SP page mapping counters");
@@ -1968,7 +1963,11 @@
 
 	/*
 	 * Are large page mappings enabled?
+	 *
+	 * While HPT superpages are not better tested, leave it disabled by
+	 * default.
 	 */
+	superpages_enabled = 0;
 	TUNABLE_INT_FETCH("vm.pmap.superpages_enabled", &superpages_enabled);
 	if (superpages_enabled) {
 		KASSERT(MAXPAGESIZES > 1 && pagesizes[1] == 0,
Index: sys/powerpc/aim/mmu_radix.c
===================================================================
--- sys/powerpc/aim/mmu_radix.c
+++ sys/powerpc/aim/mmu_radix.c
@@ -385,11 +385,8 @@
 
 vm_paddr_t dmaplimit;
 
-SYSCTL_NODE(_vm, OID_AUTO, pmap, CTLFLAG_RD, 0, "VM/pmap parameters");
+SYSCTL_DECL(_vm_pmap);
 
-static int pg_ps_enabled = 1;
-SYSCTL_INT(_vm_pmap, OID_AUTO, pg_ps_enabled, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
-    &pg_ps_enabled, 0, "Are large page mappings enabled?");
 #ifdef INVARIANTS
 #define VERBOSE_PMAP 0
 #define VERBOSE_PROTECT 0
@@ -904,7 +901,7 @@
 bool
 mmu_radix_ps_enabled(pmap_t pmap)
 {
-	return (pg_ps_enabled && (pmap->pm_flags & PMAP_PDE_SUPERPAGE) != 0);
+	return (superpages_enabled && (pmap->pm_flags & PMAP_PDE_SUPERPAGE) != 0);
 }
 
 static pt_entry_t *
@@ -3588,8 +3585,8 @@
 	/*
 	 * Are large page mappings enabled?
 	 */
-	TUNABLE_INT_FETCH("vm.pmap.pg_ps_enabled", &pg_ps_enabled);
-	if (pg_ps_enabled) {
+	TUNABLE_INT_FETCH("vm.pmap.superpages_enabled", &superpages_enabled);
+	if (superpages_enabled) {
 		KASSERT(MAXPAGESIZES > 1 && pagesizes[1] == 0,
 		    ("pmap_init: can't assign to pagesizes[1]"));
 		pagesizes[1] = L3_PAGE_SIZE;
Index: sys/powerpc/include/pmap.h
===================================================================
--- sys/powerpc/include/pmap.h
+++ sys/powerpc/include/pmap.h
@@ -336,6 +336,7 @@
 
 extern	int pmap_bootstrapped;
 extern	int radix_mmu;
+extern	int superpages_enabled;
 
 vm_offset_t pmap_early_io_map(vm_paddr_t pa, vm_size_t size);
 void pmap_early_io_unmap(vm_offset_t va, vm_size_t size);
Index: sys/powerpc/powerpc/pmap_dispatch.c
===================================================================
--- sys/powerpc/powerpc/pmap_dispatch.c
+++ sys/powerpc/powerpc/pmap_dispatch.c
@@ -50,6 +50,7 @@
 #include <sys/kerneldump.h>
 #include <sys/ktr.h>
 #include <sys/mutex.h>
+#include <sys/sysctl.h>
 #include <sys/systm.h>
 
 #include <vm/vm.h>
@@ -80,6 +81,12 @@
 /* Default level 0 reservations consist of 512 pages (2MB superpage). */
 int vm_level_0_order = 9;
 
+SYSCTL_NODE(_vm, OID_AUTO, pmap, CTLFLAG_RD, 0, "VM/pmap parameters");
+
+int superpages_enabled = 0;
+SYSCTL_INT(_vm_pmap, OID_AUTO, superpages_enabled, CTLFLAG_RDTUN,
+    &superpages_enabled, 0, "Enable support for transparent superpages");
+
 #ifdef AIM
 int
 pvo_vaddr_compare(struct pvo_entry *a, struct pvo_entry *b)