Re: Slow receive with AX8817 USB2 ethernet adapter

David T Hollis
2004-01-07T15:54:44Z

On Wed, 2004-01-07 at 08:53, MÃ¥ns RullgÃ¥rd wrote:
> mru@kth.se (MÃ¥ns RullgÃ¥rd) writes:
>
> > I'm getting very bad receive rates with a Netgear FA-120 USB2 Ethernet
> > adapter under Linux 2.6.0. Timing an incoming TCP stream, I get only
> > 600 kB/s. Sending works properly at 10 MB/s. I first reported this
> > problem some time in July or August. Is it just me having this issue?
> > Can I get any helpful information somehow?
>
Hmm, I am seeing the same results using ttcp:

**** Send Results ****
[root@dhollis-lnx dhollis]# ttcp -t -s -D -n 8192 192.168.5.1
ttcp-t: buflen=8192, nbuf=8192, align=16384/0, port=5001 tcp ->
192.168.5.1
ttcp-t: socket
ttcp-t: nodelay
ttcp-t: connect
ttcp-t: 67108864 bytes in 7.89 real seconds = 8302.39 KB/sec +++
ttcp-t: 8192 I/O calls, msec/call = 0.99, calls/sec = 1037.80
ttcp-t: 0.0user 0.1sys 0:07real 1% 0i+0d 0maxrss 0+2pf 1118+151csw

**** Receiving Results *****
[root@dhollis-lnx 2.6.0]# ttcp -r -s -D
ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001 tcp
ttcp-r: socket
ttcp-r: accept from 192.168.5.1
ttcp-r: 16777216 bytes in 25.18 real seconds = 650.68 KB/sec +++
ttcp-r: 7385 I/O calls, msec/call = 3.49, calls/sec = 293.29
ttcp-r: 0.0user 0.1sys 0:25real 0% 0i+0d 0maxrss 0+2pf 10115+163csw

[root@dhollis-lnx 2.6.0]# ttcp -r -s -D
ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001 tcp
ttcp-r: socket
ttcp-r: accept from 192.168.5.1
ttcp-r: 67108864 bytes in 5.81 real seconds = 11276.03 KB/sec +++
ttcp-r: 42074 I/O calls, msec/call = 0.14, calls/sec = 7239.19
ttcp-r: 0.0user 0.4sys 0:05real 8% 0i+0d 0maxrss 0+2pf 41000+3667csw

Notice that I was able to achieve 11MB/s at one point and I was able to
repeat those results continually. I then unloaded the module, reloaded,
re-ifconfigged and was back at the 600-700k mark. It's going to take
some further debugging to fully trace this problem out.

--
David T Hollis <dhollis@davehollis.com>