diff --git a/sys/vm/vm_map.h b/sys/vm/vm_map.h
--- a/sys/vm/vm_map.h
+++ b/sys/vm/vm_map.h
@@ -426,6 +426,7 @@
 #define VM_MAP_WIRE_HOLESOK	2	/* region may have holes */
 
 #define VM_MAP_WIRE_WRITE	4	/* Validate writable. */
+#define VM_MAP_WIRE_PREFAULT	8	/* Pre-populate whole region. */
 
 typedef int vm_map_entry_reader(void *token, vm_map_entry_t addr, 
     vm_map_entry_t dest);
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -3486,6 +3486,86 @@
 	entry->wired_count = -1;
 }
 
+/*
+ *	vm_map_wire_prefault_entry:
+ *
+ *	Preallocates pages in object to avoid performance penalties in
+ *	'vm_fault'. Used for speeding up wirings of large regions.
+ *
+ *	Will not operate on non-empty entries.
+ */
+
+static int
+vm_map_wire_prefault_entry(vm_map_t map, vm_map_entry_t entry)
+{
+	vm_pindex_t pindex;
+	vm_offset_t cur, end;
+	vm_object_t obj = entry->object.vm_object;
+	int rv = KERN_SUCCESS;
+	vm_page_t m;
+#if VM_NRESERVLEVEL > 0
+	const size_t reserv_size = 1 << (VM_LEVEL_0_ORDER + PAGE_SHIFT);
+#endif
+
+	VM_OBJECT_WLOCK(obj);
+	/* Check if the entry is empty. */
+	m = vm_page_find_least(obj, OFF_TO_IDX(entry->offset));
+	if (m != NULL
+		&& m->pindex <= OFF_TO_IDX((entry->end - entry->start) + entry->offset)){
+		VM_OBJECT_WUNLOCK(obj);
+		return (KERN_RESTART);
+	}
+	/* Populate entry's object with pages. */
+	end = entry->end;
+	cur = entry->start;
+	while (cur < end) {
+		pindex = OFF_TO_IDX((cur - entry->start) + entry->offset);
+#if VM_NRESERVLEVEL > 0
+		/* First run - try to allocate a superpage. */
+		if ((cur & (reserv_size - 1)) == 0 &&
+		    (end - cur) >= reserv_size) {
+			m = vm_page_alloc_contig(obj, pindex,
+			    VM_ALLOC_WIRED | VM_ALLOC_NOBUSY,
+			    (1 << VM_LEVEL_0_ORDER), 0, ~0, 0, 0,
+			    VM_MEMATTR_DEFAULT);
+			if (m != NULL) {
+				cur += reserv_size;
+				continue;
+			}
+		}
+#endif
+		/* Fall back to 0-order pages. */
+		m = vm_page_alloc(obj, pindex,
+		    VM_ALLOC_WIRED | VM_ALLOC_NOBUSY);
+		if (m == NULL) {
+			VM_OBJECT_WUNLOCK(obj);
+			return (KERN_NO_SPACE);
+		}
+		/* We got a 0-order page. */
+		cur += PAGE_SIZE;
+	}
+	VM_OBJECT_WUNLOCK(obj);
+
+	/*
+	 * Simulate faults to enter the previously
+	 * allocated pages into the physical map.
+	 */
+	cur = entry->start;
+	while (cur < end) {
+		rv = vm_fault(map, cur, VM_PROT_NONE, VM_FAULT_WIRE, NULL);
+		if (rv != KERN_SUCCESS)
+			break;
+
+		VM_OBJECT_RLOCK(obj);
+		m = vm_page_lookup(obj,
+		    OFF_TO_IDX((cur - entry->start) + entry->offset));
+		VM_OBJECT_RUNLOCK(obj);
+
+		cur += pagesizes[m->psind];
+	}
+	return (rv);
+}
+
 int
 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
 {
@@ -3595,6 +3675,13 @@
 			vm_map_busy(map);
 			vm_map_unlock(map);
 
+			if ((flags & VM_MAP_WIRE_PREFAULT) != 0 && user_wire &&
+			    !holes_ok) {
+				rv = vm_map_wire_prefault_entry(map, entry);
+				if (rv != KERN_RESTART)
+					goto fault_done;
+				/* Fall back to the regular wiring loop. */
+			}
 			for (faddr = saved_start; faddr < saved_end;
 			    faddr += incr) {
 				/*
@@ -3606,6 +3693,7 @@
 				if (rv != KERN_SUCCESS)
 					break;
 			}
+fault_done:
 			vm_map_lock(map);
 			vm_map_unbusy(map);
 			if (last_timestamp + 1 != map->timestamp) {