Function swap_pager_alloc_init

freebsd/vm/swap_pager.c:657–684

}

static vm_object_t
swap_pager_alloc_init(void *handle, struct ucred *cred, vm_ooffset_t size,
    vm_ooffset_t offset)
{
	vm_object_t object;

	if (cred != NULL) {
		if (!swap_reserve_by_cred(size, cred))
			return (NULL);
		crhold(cred);
	}

	/*
	 * The un_pager.swp.swp_blks trie is initialized by
	 * vm_object_allocate() to ensure the correct order of
	 * visibility to other threads.
	 */
	object = vm_object_allocate(OBJT_SWAP, OFF_TO_IDX(offset +
	    PAGE_MASK + size));

	object->un_pager.swp.writemappings = 0;
	object->handle = handle;
	if (cred != NULL) {
		object->cred = cred;
		object->charge = size;
	}
	return (object);
}

/*
 * SWAP_PAGER_ALLOC() -	allocate a new OBJT_SWAP VM object and instantiate