TXQ_STOP_THRES
if (unlikely(txq_avail(&q->q) < TXQ_STOP_THRES)) {
if (unlikely(txq_avail(&q->q) < TXQ_STOP_THRES))
BUG_ON(txq_avail(&q->q) < TXQ_STOP_THRES); /* q should be empty */
if (unlikely(txq_avail(&q->q) < TXQ_STOP_THRES)) {
if (unlikely(credits < TXQ_STOP_THRES))
if (unlikely(credits < TXQ_STOP_THRES))