diff --git a/sys/vm/uma.h b/sys/vm/uma.h
--- a/sys/vm/uma.h
+++ b/sys/vm/uma.h
@@ -483,7 +483,8 @@
 
 /*
  * Reserves the maximum KVA space required by the zone and configures the zone
- * to use a VM_ALLOC_NOOBJ-based backend allocator.
+ * to use a backend that allocates physical memory and maps it using the
+ * reserved KVA. 
  *
  * Arguments:
  *	zone  The zone to update.
diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c
--- a/sys/vm/uma_core.c
+++ b/sys/vm/uma_core.c
@@ -2014,7 +2014,7 @@
 }
 
 /*
- * Allocates a number of pages from within an object
+ * Allocates a number of pages not belonging to a VM object
  *
  * Arguments:
  *	bytes  The number of bytes requested
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -542,9 +542,10 @@
 #define	VM_ALLOC_WIRED		0x0020	/* (acgnp) Allocate a wired page */
 #define	VM_ALLOC_ZERO		0x0040	/* (acgnp) Allocate a zeroed page */
 #define	VM_ALLOC_NORECLAIM	0x0080	/* (c) Do not reclaim after failure */
-#define	VM_ALLOC_NOOBJ		0x0100	/* (acg) No associated object */
+#define	VM_ALLOC_AVAIL0		0x0100
 #define	VM_ALLOC_NOBUSY		0x0200	/* (acgp) Do not excl busy the page */
 #define	VM_ALLOC_NOCREAT	0x0400	/* (gp) Don't create a page */
+#define	VM_ALLOC_AVAIL1		0x0800
 #define	VM_ALLOC_IGN_SBUSY	0x1000	/* (gp) Ignore shared busy flag */
 #define	VM_ALLOC_NODUMP		0x2000	/* (ag) don't include in dump */
 #define	VM_ALLOC_SBUSY		0x4000	/* (acgp) Shared busy the page */