low performance of tap device on windows

[snail007]

I tried water on windos,use tap device process some IP packet traffic,
such as :
using mysql GUI client connect to local mysql server through tap device's IP,when opening table (less data),it is very slow , but without tap, it is very fast, i chehcked the go pprof ,find out that 99% CPU time is used by io.Copy.
Looking forward to your suggestion!

[lixin9311]

Thank you for report this issue.
If it is possible, can you provide the minimal code to reproduce the issue?

[snail007]

Thanks for your reply, attachment (sample.zip) is my go code and go pprof file.
My Environment :
System : windows7 64bit
TAP driver : https://build.openvpn.net/downloads/releases/tap-windows-9.22.1-I602.exe
Go version : 1.10.3
Localhost : MySQL Server
MySQL GUI Client : navicat

Constantly opening a new table in navicat will reveal a slow response.

Looking forward to your reply.

sample.zip

[weiyixuan]

You can change the TAP driver：https://build.openvpn.net/downloads/releases/tap-windows-9.9.2_3.exe
For win7，the new drivers will cause low performance.