Index: sys/vm/uma_core.c
===================================================================
--- sys/vm/uma_core.c	(revision 246940)
+++ sys/vm/uma_core.c	(working copy)
@@ -1032,38 +1032,45 @@ page_alloc(uma_zone_t zone, int bytes, u_int8_t *p
 static void *
 obj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
 {
+	u_long pages, startpages;
 	vm_object_t object;
 	vm_offset_t retkva, zkva;
 	vm_page_t p;
-	int pages, startpages;
 	uma_keg_t keg;
+	int nbytes, pflags;
 
 	keg = zone_first_keg(zone);
 	object = keg->uk_obj;
-	retkva = 0;
+	pflags = VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED;
+	if (object == NULL)
+		pflags |= VM_ALLOC_NOOBJ;
 
 	/*
 	 * This looks a little weird since we're getting one page at a time.
 	 */
-	VM_OBJECT_LOCK(object);
-	p = TAILQ_LAST(&object->memq, pglist);
-	pages = p != NULL ? p->pindex + 1 : 0;
+retry:
+	retkva = 0;
+	nbytes = howmany(bytes, PAGE_SIZE);
+	if (object != NULL)
+		VM_OBJECT_LOCK(object);
+	pages = keg->uk_offset;
 	startpages = pages;
 	zkva = keg->uk_kva + pages * PAGE_SIZE;
-	for (; bytes > 0; bytes -= PAGE_SIZE) {
-		p = vm_page_alloc(object, pages,
-		    VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED);
+	for (; nbytes > 0; nbytes--) {
+		p = vm_page_alloc(object, pages, pflags);
 		if (p == NULL) {
-			if (pages != startpages)
-				pmap_qremove(retkva, pages - startpages);
 			while (pages != startpages) {
-				pages--;
-				p = TAILQ_LAST(&object->memq, pglist);
+				zkva -= PAGE_SIZE;
+				p = PHYS_TO_VM_PAGE(pmap_kextract(zkva));
+				pmap_qremove(zkva, 1);
 				vm_page_unwire(p, 0);
 				vm_page_free(p);
+				pages--;
 			}
+			if (retkva != 0 && retkva != zkva)
+				panic("UMA: Invalid kva scanning");
 			retkva = 0;
-			goto done;
+			break;
 		}
 		pmap_qenter(zkva, &p, 1);
 		if (retkva == 0)
@@ -1071,8 +1078,20 @@ obj_alloc(uma_zone_t zone, int bytes, u_int8_t *fl
 		zkva += PAGE_SIZE;
 		pages += 1;
 	}
-done:
-	VM_OBJECT_UNLOCK(object);
+	if (object != NULL) {
+		keg->uk_offset = pages;
+		VM_OBJECT_UNLOCK(object);
+	} else if (!atomic_cmpset_long(&keg->uk_offset, startpages, pages)) {
+		while (pages != startpages) {
+			zkva -= PAGE_SIZE;
+			p = PHYS_TO_VM_PAGE(pmap_kextract(zkva));
+			pmap_qremove(zkva, 1);
+			vm_page_unwire(p, 0);
+			vm_page_free(p);
+			pages--;
+		}
+		goto retry;
+	}
 	*flags = UMA_SLAB_PRIV;
 
 	return ((void *)retkva);
@@ -3024,21 +3043,33 @@ uma_zone_set_obj(uma_zone_t zone, struct vm_object
 	if (pages * keg->uk_ipers < count)
 		pages++;
 
+#ifdef UMA_MD_SMALL_ALLOC
+	if (keg->uk_ppera > 1 || obj != NULL) {
+		kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
+		if (kva == 0)
+			return (0);
+	} else
+		kva = 0;
+#else
 	kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
-
 	if (kva == 0)
 		return (0);
-	if (obj == NULL)
-		obj = vm_object_allocate(OBJT_PHYS, pages);
-	else {
+#endif
+	if (obj != NULL) {
 		VM_OBJECT_LOCK_INIT(obj, "uma object");
 		_vm_object_allocate(OBJT_PHYS, pages, obj);
 	}
 	ZONE_LOCK(zone);
 	keg->uk_kva = kva;
 	keg->uk_obj = obj;
+	keg->uk_offset = 0;
 	keg->uk_maxpages = pages;
+#ifdef UMA_MD_SMALL_ALLOC
+	keg->uk_allocf = (keg->uk_ppera <= 1 && obj == NULL) ?
+	    uma_small_alloc : obj_alloc;
+#else
 	keg->uk_allocf = obj_alloc;
+#endif
 	keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC;
 	ZONE_UNLOCK(zone);
 	return (1);
Index: sys/vm/uma_int.h
===================================================================
--- sys/vm/uma_int.h	(revision 246940)
+++ sys/vm/uma_int.h	(working copy)
@@ -222,6 +222,7 @@ struct uma_keg {
 	uma_free	uk_freef;	/* Free routine */
 
 	struct vm_object	*uk_obj;	/* Zone specific object */
+	u_long		uk_offset;	/* Zone specific next page index */
 	vm_offset_t	uk_kva;		/* Base kva for zones with objs */
 	uma_zone_t	uk_slabzone;	/* Slab zone backing us, if OFFPAGE */
 
Index: sys/vm/vm_radix.c
===================================================================
--- sys/vm/vm_radix.c	(revision 246940)
+++ sys/vm/vm_radix.c	(working copy)
@@ -63,7 +63,7 @@
 #endif
 
 #ifndef VM_RADIX_BOOT_CACHE
-#define	VM_RADIX_BOOT_CACHE	1500
+#define	VM_RADIX_BOOT_CACHE	250
 #endif
 
 /*
@@ -373,7 +373,6 @@ vm_radix_node_zone_dtor(void *mem, int size __unus
 static void
 vm_radix_init(void *arg __unused)
 {
-	int nitems;
 
 	vm_radix_node_zone = uma_zcreate("RADIX NODE",
 	    sizeof(struct vm_radix_node), NULL,
@@ -383,10 +382,9 @@ vm_radix_init(void *arg __unused)
 	    NULL,
 #endif
 	    NULL, NULL, VM_RADIX_PAD, UMA_ZONE_VM | UMA_ZONE_NOFREE);
-	nitems = uma_zone_set_max(vm_radix_node_zone, cnt.v_page_count);
-	if (nitems < cnt.v_page_count)
-		panic("%s: unexpected requested number of items", __func__);
-	uma_prealloc(vm_radix_node_zone, nitems);
+	if (!uma_zone_set_obj(vm_radix_node_zone, NULL, cnt.v_page_count))
+		panic("%s: unable to create new zone", __func__);
+	uma_prealloc(vm_radix_node_zone, cnt.v_page_count);
 	boot_cache_cnt = VM_RADIX_BOOT_CACHE + 1;
 }
 SYSINIT(vm_radix_init, SI_SUB_KMEM, SI_ORDER_SECOND, vm_radix_init, NULL);