VKE_REF_DELETED
if ((n & VKE_REF_DELETED) == 0) {
} else if (ve->refs & VKE_REF_DELETED) {
if (n & VKE_REF_DELETED) {
if (atomic_cmpset_int(&ve->refs, refs, VKE_REF_DELETED) == 0) {
KKASSERT(ve->refs & VKE_REF_DELETED);
if (atomic_fetchadd_int(&ve->refs, 1) & VKE_REF_DELETED) {