Add benchmark results to README.

README.md

@@ -76,3 +76,27 @@ Example invocation:
 ```shell
 sudo ./go-mmproxy -l 0.0.0.0:25577 -4 127.0.0.1:25578 -6 [::1]:25578 --allowed-subnets ./path-prefixes.txt
 ```
+
+## Benchmark
+
+### Setup
+
+The benchmark was ran on Dell XPS 9570 with Intel Core i9-8950HK CPU @ 2.90GHz (12 logical cores). The upstream service to which proxy sent traffic was mocked by [bpf-echo](https://github.com/path-network/bpf-echo) server.
+Traffic was generated by [tcpkali](https://github.com/satori-com/tcpkali) v1.1.1 .
+
+The following command was used for load generation in all cases (50 connections, 10s runtime, send PROXYv1 header for each connection, use `PING\r\n` as TCP message):
+
+```
+tcpkali -c 50 -T 10s -e1 'PROXY TCP4 127.0.0.1 127.0.0.1 \{connection.uid} 25578\r\n' -m 'PING\r\n' 127.0.0.1:1122
+```
+
+### Results
+
+|                         | ⇅ Mbps    | ↓ Mbps    | ↑ Mbps    | ↓ pkt/s   | ↑ pkt/s   |
+| ----------------------- | --------- | --------- | --------- | --------- | --------- |
+| cloudflare/mmproxy      | 1524.454  | 756.385   | 768.069   | 70365.9   | 65921.9   |
+| go-mmproxy GOMAXPROCS=1 | 7418.312  | 2858.794  | 4559.518  | 262062.7  | 391334.6  |
+| go-mmproxy              | 45483.233 | 16142.348 | 29340.885 | 1477889.6 | 2518271.5 |
+| no proxy                | 52640.116 | 22561.129 | 30078.987 | 2065805.4 | 2581621.3 |
+
+![result barchart](benchmark.png)