On 2019/4/4 下午6:58, 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
Or EWMA + mergeable rx buffer, but if we decide to unify the datapath
with virtio-net, we can reuse their codes.
- 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?
My understanding is this is not a must, but if it makes things easier,
we can do this.
Another thing that may help is to implement sendpage(), which will
greatly improve the performance.
Thanks
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
[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(-)
