sys/uvm/uvm_km.c

79  * virtual address space that is mapped by a submap is locked by the
80  * submap's lock -- not the kernel_map's lock.
92  * The kmem_arena is a "special submap", as it lives in a fixed map entry
106  * object mapped into that range (e.g. a vnode).    for submap's kernel
108  * offsets that are managed by the submap.
380  * uvm_km_suballoc: allocate a submap in the kernel map.   once a submap
386  *      by the submap must start
387  * => if submap is non NULL we use that as the submap, otherwise we
394     struct vm_map *submap)
420 	 * add references to pmap and create or init the submap
424 	if (submap == NULL) {
425 		submap = kmem_alloc(sizeof(*submap), KM_SLEEP);
427 	uvm_map_setup(submap, *vmin, *vmax, flags);
428 	submap->pmap = vm_map_pmap(map);
434 	if (uvm_map_submap(map, *vmin, *vmax, submap) != 0)
435 		panic("uvm_km_suballoc: submap allocation failed");
437 	return(submap);