diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 85c53922913b..c51a9cac66cd 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -711,8 +711,6 @@ vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
 	vm_map_entry_t temp_entry;
 	vm_eflags_t protoeflags;
 
-	GIANT_REQUIRED;
-
 	/*
 	 * Check that the start and end points are not bogus.
 	 */
@@ -753,6 +751,7 @@ vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
 		protoeflags |= MAP_ENTRY_NOCOREDUMP;
 
 	if (object) {
+		GIANT_REQUIRED;
 		/*
 		 * When object is non-NULL, it could be shared with another
 		 * process.  We have to set or clear OBJ_ONEMAPPING 
@@ -847,6 +846,7 @@ vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
 #endif
 
 	if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) {
+		GIANT_REQUIRED;
 		pmap_object_init_pt(map->pmap, start,
 				    object, OFF_TO_IDX(offset), end - start,
 				    cow & MAP_PREFAULT_PARTIAL);
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index d04694153fba..b07d6b8a40b8 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -1813,18 +1813,17 @@ again:
  *	The object must *not* be locked.
  */
 boolean_t
-vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, vm_size_t prev_size, vm_size_t next_size)
+vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex,
+	vm_size_t prev_size, vm_size_t next_size)
 {
 	vm_pindex_t next_pindex;
 
-	GIANT_REQUIRED;
-
-	if (prev_object == NULL) {
+	if (prev_object == NULL)
 		return (TRUE);
-	}
-
+	mtx_lock(&Giant);
 	if (prev_object->type != OBJT_DEFAULT &&
 	    prev_object->type != OBJT_SWAP) {
+		mtx_unlock(&Giant);
 		return (FALSE);
 	}
 
@@ -1839,6 +1838,7 @@ vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, vm_size_t p
 	 * pages not mapped to prev_entry may be in use anyway)
 	 */
 	if (prev_object->backing_object != NULL) {
+		mtx_unlock(&Giant);
 		return (FALSE);
 	}
 
@@ -1848,6 +1848,7 @@ vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, vm_size_t p
 
 	if ((prev_object->ref_count > 1) &&
 	    (prev_object->size != next_pindex)) {
+		mtx_unlock(&Giant);
 		return (FALSE);
 	}
 
@@ -1870,6 +1871,7 @@ vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, vm_size_t p
 	if (next_pindex + next_size > prev_object->size)
 		prev_object->size = next_pindex + next_size;
 
+	mtx_unlock(&Giant);
 	return (TRUE);
 }