prepare_reply
rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb,
rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size);