Hello Mohammad,
could you please switch to the current master branch? The "rpi_usb" branch is out of date. It was just a topic branch for the USB SOF optimzation, which ended up the master branch already.
I cannot explain your observation. To investigate, you may use wireshark to monitor the traffic in both cases (Linux vs. OpenBSD in the VM) and look for the TCP protocol parameters. Maybe Linux uses a very small TCP window in the bad case?
when i run the test from OpenBSD in the debug output of netperf in the Rpi I get meaasges like
[init] child "netserver_genode" request resources :ram_quota= XXXXX
We don't have these messages in our log but we use a different branch.
The messages should not interfere with the throughput. They just hint at a misconfiguration of the RAM quota assigned to the netserver_genode process. The process tries to allocate more memory than assigned. But since init has still slack memory available, it is handing out the needed memory on demand.
Cheers Norman