In this case, if rx_queue_stopped is true, then we're expecting frontend>Sorry, I should wrote rx_queue_stopped to trueThe recent patch to fix receive side flow control (11b57f) solved the spinning> >
> >>thread problem, however caused an another one. The receive side can stall, if:
> >>- xenvif_rx_action sets rx_queue_stopped to false
> >>- interrupt happens, and sets rx_event to true
> >>- then xenvif_kthread sets rx_event to false
> >>
> >If you mean "rx_work_todo" returns false.
> >
> >In this case
> >
> >(!skb_queue_empty(&vif->rx_queue) && !vif->rx_queue_stopped) || vif->rx_event;
> >
> >can still be true, can't it?
>
to notify us, right?
rx_queue_stopped is set to true if we cannot make any progress to queue
packet into the ring. In that situation we can expect frontend will send
notification to backend after it goes through the backlog in the ring.
That means rx_event is set to true, and rx_work_todo is true again. So
the ring is actually not stalled in this case as well. Did I miss
something?