rctlblk_get_recipient_pid
pid = rctlblk_get_recipient_pid(iter_val->rblk);
pid = rctlblk_get_recipient_pid(rctl);
rctlblk_get_recipient_pid(rctlblkA),
rctlblk_get_recipient_pid(rctlblkA),
pid = rctlblk_get_recipient_pid(rctlblkA);
rctlblk_get_recipient_pid(rctlblkA),
rctlblk_get_recipient_pid(blk));
id_t rctlblk_get_recipient_pid(rctlblk_t *);