_KDEREF
#define KDEREF(kd, item) _KDEREF((kd), A(item), D(item, data), S(item))
_KDEREF(kd, nl[NL_MAXSSIZ].n_value, &maxssiz,
_KDEREF(kd, nl[NL_KERNEL_MAP].n_value, &kernel_map_addr,
_KDEREF(kd, nclruhead_addr, &nchead, sizeof(nchead));
_KDEREF(kd, (u_long)tmp, &n, sizeof(n));