On Thu, Apr 04, 2019 at 12:58:34PM +0200, Stefano Garzarella wrote: > This series tries to increase the throughput of virtio-vsock with slight > changes: > - patch 1/4: reduces the number of credit update messages sent to the > transmitter > - patch 2/4: allows the host to split packets on multiple buffers, > in this way, we can remove the packet size limit to > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE > - patch 3/4: uses VIRTIO_VSOCK_MAX_PKT_BUF_SIZE as the max packet size > allowed > - patch 4/4: increases RX buffer size to 64 KiB (affects only host->guest) > > RFC: > - maybe patch 4 can be replaced with multiple queues with different > buffer sizes or using EWMA to adapt the buffer size to the traffic > > - as Jason suggested in a previous thread [1] I'll evaluate to use > virtio-net as transport, but I need to understand better how to > interface with it, maybe introducing sk_buff in virtio-vsock. > > Any suggestions? > > Here some benchmarks step by step. I used iperf3 [2] modified with VSOCK > support: > > host -> guest [Gbps] > pkt_size before opt. patch 1 patches 2+3 patch 4 > 64 0.060 0.102 0.102 0.096 > 256 0.22 0.40 0.40 0.36 > 512 0.42 0.82 0.85 0.74 > 1K 0.7 1.6 1.6 1.5 > 2K 1.5 3.0 3.1 2.9 > 4K 2.5 5.2 5.3 5.3 > 8K 3.9 8.4 8.6 8.8 > 16K 6.6 11.1 11.3 12.8 > 32K 9.9 15.8 15.8 18.1 > 64K 13.5 17.4 17.7 21.4 > 128K 17.9 19.0 19.0 23.6 > 256K 18.0 19.4 19.8 24.4 > 512K 18.4 19.6 20.1 25.3 > > guest -> host [Gbps] > pkt_size before opt. patch 1 patches 2+3 > 64 0.088 0.100 0.101 > 256 0.35 0.36 0.41 > 512 0.70 0.74 0.73 > 1K 1.1 1.3 1.3 > 2K 2.4 2.4 2.6 > 4K 4.3 4.3 4.5 > 8K 7.3 7.4 7.6 > 16K 9.2 9.6 11.1 > 32K 8.3 8.9 18.1 > 64K 8.3 8.9 25.4 > 128K 7.2 8.7 26.7 > 256K 7.7 8.4 24.9 > 512K 7.7 8.5 25.0 > > Thanks, > Stefano I simply love it that you have analysed the individual impact of each patch! Great job! For comparison's sake, it could be IMHO benefitial to add a column with virtio-net+vhost-net performance. This will both give us an idea about whether the vsock layer introduces inefficiencies, and whether the virtio-net idea has merit. One other comment: it makes sense to test with disabling smap mitigations (boot host and guest with nosmap). No problem with also testing the default smap path, but I think you will discover that the performance impact of smap hardening being enabled is often severe for such benchmarks. > [1] https://www.spinics.net/lists/netdev/msg531783.html > [2] https://github.com/stefano-garzarella/iperf/ > > Stefano Garzarella (4): > vsock/virtio: reduce credit update messages > vhost/vsock: split packets to send using multiple buffers > vsock/virtio: change the maximum packet size allowed > vsock/virtio: increase RX buffer size to 64 KiB > > drivers/vhost/vsock.c | 35 ++++++++++++++++++++----- > include/linux/virtio_vsock.h | 3 ++- > net/vmw_vsock/virtio_transport_common.c | 18 +++++++++---- > 3 files changed, 44 insertions(+), 12 deletions(-) > > -- > 2.20.1
