Alexander Wetzel <alexander@xxxxxxxxxxxxxx> writes: > I still don't understand why we don't want to use qdisc with the iTXQ > drivers. I now just made sure we don't start using qdiscs with this > patch to start with the least invasive approach. Anyone able to shed > some light on that? Because of aggregation, basically. To build an aggregate you need to be able to pull several packets that has the same STA+TID; if all packets on the interface are just sitting in a qdisc you have no interface to do this. Before switching to TXQs, drivers (the ath9k in particular) would solve this by having another layer of per-sta queueing inside the driver, which was just a dump FIFO that added a bunch of latency. The iTXQs moved that up to mac80211, while doing proper queue management (flow queueing + CoDel derived from the FQ-CoDel qdisc) at the same time; this made the qdisc layer redundant for most purposes, which is why we switched to noqueue by default. -Toke
