"Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote on 10/25/2010 09:47:18 PM: > > Any feedback, comments, objections, issues or bugs about the > > patches? Please let me know if something needs to be done. > > I am trying to wrap my head around kernel/user interface here. > E.g., will we need another incompatible change when we add multiple RX > queues? Though I added a 'mq' option to qemu, there shouldn't be any incompatibility between old and new qemu's wrt vhost and virtio-net drivers. So the old qemu will run new host and new guest without issues, and new qemu can also run old host and old guest. Multiple RXQ will also not add any incompatibility. With MQ RX, I will be able to remove the hueristic (idea from David Stevens). The idea is: Guest sends out packets on, say TXQ#2, vhost#2 processes the packets but packets going out from host to guest might be sent out on a different RXQ, say RXQ#4. Guest receives the packet on RXQ#4, and all future responses on that connection are sent on TXQ#4. Now vhost#4 processes both RX and TX packets for this connection. Without needing to hash on the connection, guest can make sure that the same vhost thread will handle a single connection. > Also need to think about how robust our single stream heuristic is, > e.g. what are the chances it will misdetect a bidirectional > UDP stream as a single TCP? I think it should not happen. The hueristic code gets called for handling just the transmit packets, packets that vhost sends out to the guest skip this path. I tested unidirectional and bidirectional UDP to confirm: 8 iterations of iperf tests, each iteration of 15 secs, result is the sum of all 8 iterations in Gbits/sec __________________________________________ Uni-directional Bi-directional Org New Org New __________________________________________ 71.78 71.77 71.74 72.07 __________________________________________ Thanks, - KK -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
