Merge branch 'vsock-virtio-optimizations-to-increase-the-throughput'
Stefano Garzarella says:
====================
vsock/virtio: optimizations to increase the throughput
This series tries to increase the throughput of virtio-vsock with slight
changes.
While I was testing the v2 of this series I discovered an huge use of memory,
so I added patch 1 to mitigate this issue. I put it in this series in order
to better track the performance trends.
v5:
- rebased all patches on net-next
- added Stefan's R-b and Michael's A-b
v4: https://patchwork.kernel.org/cover/11047717
v3: https://patchwork.kernel.org/cover/10970145
v2: https://patchwork.kernel.org/cover/10938743
v1: https://patchwork.kernel.org/cover/10885431
Below are the benchmarks step by step. I used iperf3 [1] modified with VSOCK
support. As Michael suggested in the v1, I booted host and guest with 'nosmap'.
A brief description of patches:
- Patches 1: limit the memory usage with an extra copy for small packets
- Patches 2+3: reduce the number of credit update messages sent to the
transmitter
- Patches 4+5: allow the host to split packets on multiple buffers and use
VIRTIO_VSOCK_MAX_PKT_BUF_SIZE as the max packet size allowed
host -> guest [Gbps]
pkt_size before opt p 1 p 2+3 p 4+5
32 0.032 0.030 0.048 0.051
64 0.061 0.059 0.108 0.117
128 0.122 0.112 0.227 0.234
256 0.244 0.241 0.418 0.415
512 0.459 0.466 0.847 0.865
1K 0.927 0.919 1.657 1.641
2K 1.884 1.813 3.262 3.269
4K 3.378 3.326 6.044 6.195
8K 5.637 5.676 10.141 11.287
16K 8.250 8.402 15.976 16.736
32K 13.327 13.204 19.013 20.515
64K 21.241 21.341 20.973 21.879
128K 21.851 22.354 21.816 23.203
256K 21.408 21.693 21.846 24.088
512K 21.600 21.899 21.921 24.106
guest -> host [Gbps]
pkt_size before opt p 1 p 2+3 p 4+5
32 0.045 0.046 0.057 0.057
64 0.089 0.091 0.103 0.104
128 0.170 0.179 0.192 0.200
256 0.364 0.351 0.361 0.379
512 0.709 0.699 0.731 0.790
1K 1.399 1.407 1.395 1.427
2K 2.670 2.684 2.745 2.835
4K 5.171 5.199 5.305 5.451
8K 8.442 8.500 10.083 9.941
16K 12.305 12.259 13.519 15.385
32K 11.418 11.150 11.988 24.680
64K 10.778 10.659 11.589 35.273
128K 10.421 10.339 10.939 40.338
256K 10.300 9.719 10.508 36.562
512K 9.833 9.808 10.612 35.979
As Stefan suggested in the v1, I measured also the efficiency in this way:
efficiency = Mbps / (%CPU_Host + %CPU_Guest)
The '%CPU_Guest' is taken inside the VM. I know that it is not the best way,
but it's provided for free from iperf3 and could be an indication.
host -> guest efficiency [Mbps / (%CPU_Host + %CPU_Guest)]
pkt_size before opt p 1 p 2+3 p 4+5
32 0.35 0.45 0.79 1.02
64 0.56 0.80 1.41 1.54
128 1.11 1.52 3.03 3.12
256 2.20 2.16 5.44 5.58
512 4.17 4.18 10.96 11.46
1K 8.30 8.26 20.99 20.89
2K 16.82 16.31 39.76 39.73
4K 30.89 30.79 74.07 75.73
8K 53.74 54.49 124.24 148.91
16K 80.68 83.63 200.21 232.79
32K 132.27 132.52 260.81 357.07
64K 229.82 230.40 300.19 444.18
128K 332.60 329.78 331.51 492.28
256K 331.06 337.22 339.59 511.59
512K 335.58 328.50 331.56 504.56
guest -> host efficiency [Mbps / (%CPU_Host + %CPU_Guest)]
pkt_size before opt p 1 p 2+3 p 4+5
32 0.43 0.43 0.53 0.56
64 0.85 0.86 1.04 1.10
128 1.63 1.71 2.07 2.13
256 3.48 3.35 4.02 4.22
512 6.80 6.67 7.97 8.63
1K 13.32 13.31 15.72 15.94
2K 25.79 25.92 30.84 30.98
4K 50.37 50.48 58.79 59.69
8K 95.90 96.15 107.04 110.33
16K 145.80 145.43 143.97 174.70
32K 147.06 144.74 146.02 282.48
64K 145.25 143.99 141.62 406.40
128K 149.34 146.96 147.49 489.34
256K 156.35 149.81 152.21 536.37
512K 151.65 150.74 151.52 519.93
[1] https://github.com/stefano-garzarella/iperf/
====================
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
