Slow receive with AX8817 USB2 ethernet adapter

Slow receive with AX8817 USB2 ethernet adapter

[Måns Rullgård]

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?

-- 
Måns Rullgård
mru@kth.se

Re: Slow receive with AX8817 USB2 ethernet adapter

[Måns Rullgård]

mru@kth.se (Måns Rullgård) 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?

I can add that mii-tool reports this:

eth0: negotiated 100baseTx-FD flow-control, link ok
  product info: vendor 00:00:20, model 32 rev 1
  basic mode:   autonegotiation enabled
  basic status: autonegotiation complete, link ok
  capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
  advertising:  100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control
  link partner: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control

-- 
Måns Rullgård
mru@kth.se

Re: Slow receive with AX8817 USB2 ethernet adapter

[David T Hollis]

On Wed, 2004-01-07 at 08:53, Måns Rullgård wrote:
> mru@kth.se (Måns Rullgård) 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>

Re: Slow receive with AX8817 USB2 ethernet adapter

[David T Hollis]

On Wed, 2004-01-07 at 10:54, David T Hollis wrote:
> On Wed, 2004-01-07 at 08:53, Måns Rullgård wrote:
> > mru@kth.se (Måns Rullgård) 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:
> 
Some more results.  This time I walked away for a few minutes, came back
and ran the test again and started getting the 10MB numbers again.  No
driver unload, etc.  Interesting thing is the I/O calls and time per
call.  I'm curious as to whether  the varying results are tied to memory
allocation, locking, or what.

[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 24.33 real seconds = 673.40 KB/sec +++
ttcp-r: 7523 I/O calls, msec/call = 3.31, calls/sec = 309.20
ttcp-r: 0.0user 0.1sys 0:24real 0% 0i+0d 0maxrss 0+2pf 10348+204csw
[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 26.47 real seconds = 618.95 KB/sec +++
ttcp-r: 7623 I/O calls, msec/call = 3.56, calls/sec = 287.98
ttcp-r: 0.0user 0.2sys 0:26real 0% 0i+0d 0maxrss 0+2pf 10502+218csw
[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 1.49 real seconds = 11011.40 KB/sec +++
ttcp-r: 10862 I/O calls, msec/call = 0.14, calls/sec = 7300.16
ttcp-r: 0.0user 0.1sys 0:01real 8% 0i+0d 0maxrss 0+2pf 10685+712csw
[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 1.49 real seconds = 10994.16 KB/sec +++
ttcp-r: 10722 I/O calls, msec/call = 0.14, calls/sec = 7194.79
ttcp-r: 0.0user 0.0sys 0:01real 6% 0i+0d 0maxrss 0+2pf 10467+1568csw
[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 5.86 real seconds = 11183.02 KB/sec +++
ttcp-r: 42708 I/O calls, msec/call = 0.14, calls/sec = 7287.66
ttcp-r: 0.0user 0.4sys 0:05real 8% 0i+0d 0maxrss 0+2pf 41508+8406csw

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

Re: Slow receive with AX8817 USB2 ethernet adapter

[Måns Rullgård]

David T Hollis <dhollis@davehollis.com> writes:

> On Wed, 2004-01-07 at 10:54, David T Hollis wrote:
>> On Wed, 2004-01-07 at 08:53, Måns Rullgård wrote:
>> > mru@kth.se (Måns Rullgård) 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:
>> 
> Some more results.  This time I walked away for a few minutes, came back
> and ran the test again and started getting the 10MB numbers again.  No
> driver unload, etc.  Interesting thing is the I/O calls and time per
> call.  I'm curious as to whether  the varying results are tied to memory
> allocation, locking, or what.

Just a very unscientific observation: my laptop emits a noise when the
ethernet is used.  The pitch depends on the transfer rate.  When
communicating with a working machine, and receiving from the ax8817,
there is a continuous high-pitch sound.  When sending to the ax8817,
the sound has a much lower pitch (not surprising) and is also
intermittent with bursts lasting < 1/2 second followed by an
approximately 1/2 second pause.  The lights on the switch behave
similarly.

-- 
Måns Rullgård
mru@kth.se