softdep_worklist_tail
ump->softdep_worklist_tail = wk;
LIST_INSERT_AFTER(ump->softdep_worklist_tail, wk, wk_list);
ump->softdep_worklist_tail = wk;
if (ump->softdep_worklist_tail == wk)
ump->softdep_worklist_tail =
if (ump->softdep_worklist_tail == &sentinel)
ump->softdep_worklist_tail =