[netperf-talk] Issues using parallel sessions of netperf

[Srikanth Sundaresan]

Hi,
We are a group from Georgia Tech working on building a benchmarking
suite for home broadband internet. I've been testing netperf out as the
throughput tool.
In order to fully saturate the link, I'm running 3 netperf sessions
simultaneously. However, this causes 1 or two of the sessions to fail
with the following error:

send_tcp_maerts: data recv error: Interrupted system call.
The output also has the following error: len was -1

This only seems to occur on the TCP_MAERTS test; the TCP_STREAM test
seems to work fine (caveat: this is from a few dozen runs). Also, if I
run only 1 session, TCP_MAERTS works.

Here's a sample output:
bin/netperf -l30 -P0 -fk -t TCP_MAERTS -p14536 143.215.129.122
bin/netperf -l30 -P0 -fk -t TCP_MAERTS -p14536 143.215.129.122
bin/netperf -l30 -P0 -fk -t TCP_MAERTS -p14536 143.215.129.122
send_tcp_maerts: data recv error: Interrupted system call

In this example, one session failed. I tried opening 3 instances of
netserver on the server on 3 ports, but the same error occurred.

I'm using netperf 2.4.5 on Linux 2.6.32. Please let me know if you need
more information. Any help would be greatly appreciated.

Thanks,
Srikanth