INP_ONLIST
if (inp->inp_flags & INP_ONLIST)
KASSERT((inp->inp_flags & INP_ONLIST) == 0, ("already on pcblist"));
inp->inp_flags |= INP_ONLIST;
KASSERT(inp->inp_flags & INP_ONLIST, ("not on pcblist"));
inp->inp_flags &= ~INP_ONLIST;