BeagleBone slow inbound net I/O

[Paul Mather]

On Mar 12, 2015, at 11:26 PM, Brett Wynkoop <freebsd-arm at wynn.com> wrote:

> Greeting-
> 
> It is confirmed, the net I/O is much slower than reading from the SD
> card.  Here is another run of tar - pipe - tar, but this time the
> source is the sd card and the destination is still the USB zfs.


The Beaglebone uses a USB NIC so any I/O to/from SD card will be competing for resources and potentially slowing things down.

Have you tried outputting to /dev/null to get a more accurate sense of how performant the network I/O alone is?  Alternatively, how about using something like benchmarks/netperf?

I just tried transferring a big file from another system to my Beaglebone Black via "nc", piping the output to /dev/null on the Beaglebone Black, and I am maxing out the 100 Mbit connection:

pmather at beaglebone:~ % netstat -w 1 -I cpsw0
            input          cpsw0           output
   packets  errs idrops      bytes    packets  errs      bytes colls
         0     0     0   12325666          0     0     269572     0
         0     0     0   12302830          0     0     268372     0
         0     0     0   12343768          0     0     291730     0
         0     0     0   12281634          0     0     267910     0
         0     0     0   12284722          0     0     267976     0
         0     0     0   12320998          0     0     268768     0
         0     0     0   12299862          0     0     268306     0
         0     0     0   12290778          0     0     268150     0
         0     0     0   12315002          0     0     268636     0
         0     0     0   12269522          0     0     267646     0
         0     0     0   12322572          0     0     268834     0
         0     0     0   12328568          0     0     268900     0
         0     0     0   12311974          0     0     268570     0
         0     0     0   12281634          0     0     267910     0
         0     0     0   12302890          0     0     268372     0
         0     0     0   12304344          0     0     268438     0
         0     0     0   12289264          0     0     268042     0
         0     0     0   12311914          0     0     268570     0
         0     0     0   12302890          0     0     268372     0
         0     0     0   11554466          0     0     252070     0
         0     0     0   12315002          0     0     268636     0
            input          cpsw0           output
   packets  errs idrops      bytes    packets  errs      bytes colls
         0     0     0   12307372          0     0     268616     0
         0     0     0   12289264          0     0     268042     0
         0     0     0   12314942          0     0     268636     0
         0     0     0   12299862          0     0     268306     0
^C

So, from my experience, inbound network I/O is as good as can be expected, at least on the Beaglebone Black.

Cheers,

Paul.