Index: vm/vm_page.c
===================================================================
--- vm/vm_page.c
+++ vm/vm_page.c
@@ -1486,13 +1486,12 @@
 	vm_page_t m, mpred;
 	int flags, req_class;
 
-	mpred = 0;	/* XXX: pacify gcc */
+	mpred = NULL;	/* XXX: pacify gcc */
 	KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
 	    (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
 	    ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
 	    (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
-	    ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object,
-	    req));
+	    ("vm_page_alloc: inconsistent object(%p)/req(%x)", object, req));
 	if (object != NULL)
 		VM_OBJECT_ASSERT_WLOCKED(object);
 
@@ -1596,10 +1595,11 @@
 				atomic_subtract_int(&vm_cnt.v_wire_count, 1);
 				m->wire_count = 0;
 			}
-			m->object = NULL;
+			KASSERT(m->object == NULL, ("page %p has object", m));
 			m->oflags = VPO_UNMANAGED;
 			m->busy_lock = VPB_UNBUSIED;
-			vm_page_free(m);
+			/* Don't change PG_ZERO. */
+			vm_page_free_toq(m);
 			return (NULL);
 		}
 
@@ -1641,6 +1641,8 @@
  *	memory attribute setting for the physical pages cannot be configured
  *	to VM_MEMATTR_DEFAULT.
  *
+ *	The specified object may not contain fictitious pages.
+ *
  *	The caller must always specify an allocation class.
  *
  *	allocation classes:
@@ -1664,20 +1666,21 @@
     u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
     vm_paddr_t boundary, vm_memattr_t memattr)
 {
-	vm_page_t m, m_tmp, m_ret;
-	u_int flags;
+	vm_page_t m, m_ret, mpred;
+	u_int busy_lock, flags, oflags;
 	int req_class;
 
+	mpred = NULL;	/* XXX: pacify gcc */
 	KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
 	    (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
 	    ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
 	    (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
-	    ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object,
+	    ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object,
 	    req));
 	if (object != NULL) {
 		VM_OBJECT_ASSERT_WLOCKED(object);
-		KASSERT(object->type == OBJT_PHYS,
-		    ("vm_page_alloc_contig: object %p isn't OBJT_PHYS",
+		KASSERT((object->flags & OBJ_FICTITIOUS) == 0,
+		    ("vm_page_alloc_contig: object %p has fictitious pages",
 		    object));
 	}
 	KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
@@ -1689,6 +1692,16 @@
 	if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
 		req_class = VM_ALLOC_SYSTEM;
 
+	if (object != NULL) {
+		mpred = vm_radix_lookup_le(&object->rtree, pindex);
+		KASSERT(mpred == NULL || mpred->pindex != pindex,
+		    ("vm_page_alloc_contig: pindex already allocated"));
+	}
+
+	/*
+	 * Can we allocate the pages without the number of free pages falling
+	 * below the lower bound for the allocation class?
+	 */
 	mtx_lock(&vm_page_queue_free_mtx);
 	if (vm_cnt.v_free_count >= npages + vm_cnt.v_free_reserved ||
 	    (req_class == VM_ALLOC_SYSTEM &&
@@ -1695,12 +1708,18 @@
 	    vm_cnt.v_free_count >= npages + vm_cnt.v_interrupt_free_min) ||
 	    (req_class == VM_ALLOC_INTERRUPT &&
 	    vm_cnt.v_free_count >= npages)) {
+		/*
+		 * Can we allocate the pages from a reservation?
+		 */
 #if VM_NRESERVLEVEL > 0
 retry:
 		if (object == NULL || (object->flags & OBJ_COLORED) == 0 ||
 		    (m_ret = vm_reserv_alloc_contig(object, pindex, npages,
-		    low, high, alignment, boundary)) == NULL)
+		    low, high, alignment, boundary, mpred)) == NULL)
 #endif
+			/*
+			 * If not, allocate them from the free page queues.
+			 */
 			m_ret = vm_phys_alloc_contig(npages, low, high,
 			    alignment, boundary);
 	} else {
@@ -1732,6 +1751,13 @@
 		flags = PG_ZERO;
 	if ((req & VM_ALLOC_NODUMP) != 0)
 		flags |= PG_NODUMP;
+	oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
+	    VPO_UNMANAGED : 0;
+	busy_lock = VPB_UNBUSIED;
+	if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
+		busy_lock = VPB_SINGLE_EXCLUSIVER;
+	if ((req & VM_ALLOC_SBUSY) != 0)
+		busy_lock = VPB_SHARERS_WORD(1);
 	if ((req & VM_ALLOC_WIRED) != 0)
 		atomic_add_int(&vm_cnt.v_wire_count, npages);
 	if (object != NULL) {
@@ -1742,37 +1768,32 @@
 	for (m = m_ret; m < &m_ret[npages]; m++) {
 		m->aflags = 0;
 		m->flags = (m->flags | PG_NODUMP) & flags;
-		m->busy_lock = VPB_UNBUSIED;
-		if (object != NULL) {
-			if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
-				m->busy_lock = VPB_SINGLE_EXCLUSIVER;
-			if ((req & VM_ALLOC_SBUSY) != 0)
-				m->busy_lock = VPB_SHARERS_WORD(1);
-		}
+		m->busy_lock = busy_lock;
 		if ((req & VM_ALLOC_WIRED) != 0)
 			m->wire_count = 1;
-		/* Unmanaged pages don't use "act_count". */
-		m->oflags = VPO_UNMANAGED;
+		m->act_count = 0;
+		m->oflags = oflags;
 		if (object != NULL) {
-			if (vm_page_insert(m, object, pindex)) {
-				if (vm_paging_needed())
-					pagedaemon_wakeup();
+			if (vm_page_insert_after(m, object, pindex, mpred)) {
+				pagedaemon_wakeup();
 				if ((req & VM_ALLOC_WIRED) != 0)
-					atomic_subtract_int(&vm_cnt.v_wire_count,
-					    npages);
-				for (m_tmp = m, m = m_ret;
-				    m < &m_ret[npages]; m++) {
-					if ((req & VM_ALLOC_WIRED) != 0)
+					atomic_subtract_int(
+					    &vm_cnt.v_wire_count, npages);
+				KASSERT(m->object == NULL,
+				    ("page %p has object", m));
+				mpred = m;
+				for (m = m_ret; m < &m_ret[npages]; m++) {
+					if (m <= mpred &&
+					    (req & VM_ALLOC_WIRED) != 0)
 						m->wire_count = 0;
-					if (m >= m_tmp) {
-						m->object = NULL;
-						m->oflags |= VPO_UNMANAGED;
-					}
+					m->oflags = VPO_UNMANAGED;
 					m->busy_lock = VPB_UNBUSIED;
-					vm_page_free(m);
+					/* Don't change PG_ZERO. */
+					vm_page_free_toq(m);
 				}
 				return (NULL);
 			}
+			mpred = m;
 		} else
 			m->pindex = pindex;
 		if (memattr != VM_MEMATTR_DEFAULT)
@@ -1791,6 +1812,7 @@
 vm_page_alloc_check(vm_page_t m)
 {
 
+	KASSERT(m->object == NULL, ("page %p has object", m));
 	KASSERT(m->queue == PQ_NONE,
 	    ("page %p has unexpected queue %d", m, m->queue));
 	KASSERT(m->wire_count == 0, ("page %p is wired", m));
Index: vm/vm_reserv.h
===================================================================
--- vm/vm_reserv.h
+++ vm/vm_reserv.h
@@ -47,7 +47,7 @@
  */
 vm_page_t	vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex,
 		    u_long npages, vm_paddr_t low, vm_paddr_t high,
-		    u_long alignment, vm_paddr_t boundary);
+		    u_long alignment, vm_paddr_t boundary, vm_page_t mpred);
 vm_page_t	vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex,
 		    vm_page_t mpred);
 void		vm_reserv_break_all(vm_object_t object);
Index: vm/vm_reserv.c
===================================================================
--- vm/vm_reserv.c
+++ vm/vm_reserv.c
@@ -404,14 +404,18 @@
  * physical address boundary that is a multiple of that value.  Both
  * "alignment" and "boundary" must be a power of two.
  *
+ * The page "mpred" must immediately precede the offset "pindex" within the
+ * specified object.
+ *
  * The object and free page queue must be locked.
  */
 vm_page_t
 vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages,
-    vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
+    vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
+    vm_page_t mpred)
 {
 	vm_paddr_t pa, size;
-	vm_page_t m, m_ret, mpred, msucc;
+	vm_page_t m, m_ret, msucc;
 	vm_pindex_t first, leftcap, rightcap;
 	vm_reserv_t rv;
 	u_long allocpages, maxpages, minpages;
@@ -448,10 +452,11 @@
 	/*
 	 * Look for an existing reservation.
 	 */
-	mpred = vm_radix_lookup_le(&object->rtree, pindex);
 	if (mpred != NULL) {
+		KASSERT(mpred->object == object,
+		    ("vm_reserv_alloc_contig: object doesn't contain mpred"));
 		KASSERT(mpred->pindex < pindex,
-		    ("vm_reserv_alloc_contig: pindex already allocated"));
+		    ("vm_reserv_alloc_contig: mpred doesn't precede pindex"));
 		rv = vm_reserv_from_page(mpred);
 		if (rv->object == object && vm_reserv_has_pindex(rv, pindex))
 			goto found;
@@ -460,7 +465,7 @@
 		msucc = TAILQ_FIRST(&object->memq);
 	if (msucc != NULL) {
 		KASSERT(msucc->pindex > pindex,
-		    ("vm_reserv_alloc_contig: pindex already allocated"));
+		    ("vm_reserv_alloc_contig: msucc doesn't succeed pindex"));
 		rv = vm_reserv_from_page(msucc);
 		if (rv->object == object && vm_reserv_has_pindex(rv, pindex))
 			goto found;