On Thu, 2016-11-17 at 14:42 +0100, Jesper Dangaard Brouer wrote: > I can see that qdisc layer does not activate xmit_more in this case. >
Sure. Not enough pressure from the sender(s). The bottleneck is not the NIC or qdisc in your case, meaning that BQL limit is kept at a small value. (BTW not all NIC have expensive doorbells)
