jasowang <jasowang@xxxxxxxxxx> wrote on 11/24/2011 06:30:52 PM: > > >> On Thu, Nov 24, 2011 at 01:47:14PM +0530, Krishna Kumar wrote: > >>> It was reported that the macvtap device selects a > >>> different vhost (when used with multiqueue feature) > >>> for incoming packets of a single connection. Use > >>> packet hash first. Patch tested on MQ virtio_net. > >> So this is sure to address the problem, why exactly does this happen? > >> Does your device spread a single flow across multiple RX queues? Would > >> not that cause trouble in the TCP layer? > >> It would seem that using the recorded queue should be faster with > >> less cache misses. Before we give up on that, I'd > >> like to understand why it's wrong. Do you know? > > I am using ixgbe. From what I briefly saw, ixgbe_alloc_rx_buffers > > calls skb_record_rx_queue when a skb is allocated. When a packet > > is received (ixgbe_alloc_rx_buffers), it sets rxhash. The > > recorded value is different for most skbs when I ran a single > > stream TCP stream test (does skbs move between the rx_rings?). > > Yes, it moves. It depends on last processor or tx queue who transmits > the packets of this stream. Because ixgbe select tx queue based on the > processor id, so if vhost thread transmits skbs on different processors, > the skb of a single stream may comes from different rx ring. But I don't see transmit going on different queues, only incoming. - KK _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
