wrk->ctrl_head = clib_llist_make_head (wrk->event_elts, evt_list);
wrk->new_head = clib_llist_make_head (wrk->event_elts, evt_list);
wrk->old_head = clib_llist_make_head (wrk->event_elts, evt_list);
wrk->ctrl_head = clib_llist_make_head (wrk->event_elts, evt_list);
wrk->new_head = clib_llist_make_head (wrk->event_elts, evt_list);
wrk->old_head = clib_llist_make_head (wrk->event_elts, evt_list);