On Tue, Jan 14, 2014 at 07:28:39PM +0000, Zoltan Kiss wrote: > The 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? > Also, through rx_event a malicious guest can force the RX thread to spin. This > patch ditch that two variable, and rework rx_work_todo. If the thread finds it This seems to be a bigger problem. Can you elaborate? Wei. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
