Yibo Zhao <yiboz@xxxxxxxxxxxxxx> writes: >> I can see why we need the second part (basically, this happens because >> I >> forgot to add a check for "no eligible stations" in may_transmit(), >> like >> the one in next_txq()). And rounding up the division result doesn't >> hurt, I guess. But why does it help to change the grace period if we're >> doing all the other stuff? > In multi-clients case, it is possible a TXQ sometimes gets drained due > to FW has deep queue and few packets in TXQ at that time. So the TXQ is > removed from the rbtree after dequeuing. When it is about to added back > very soon after the removal, the g_vt might have gone a little far away > from sta vt where sync is needed. With this sync, the station is forced > to catch up with the g_vt, however, its chance for transmission has been > reduced. I think 500us is quite a short period in multi-clients case. That's a good point, actually: Having the grace period be too small will allow stations that leave and re-enter the queue to "skip ahead" and use more than its share. However, I think it's a separate issue from what this patch is about; so how about I just increase the grace period in the next version of the base patch? -Toke
