TXQ_RUNNING
if (test_and_set_bit(TXQ_RUNNING, &q->flags) == 0) {
set_bit(TXQ_RUNNING, &q->flags);
clear_bit(TXQ_RUNNING, &qs->txq[TXQ_ETH].flags);
clear_bit(TXQ_RUNNING, &qs->txq[TXQ_OFLD].flags);