Re: Slow receive with AX8817 USB2 ethernet adapter

David T Hollis
2004-01-07T16:13:50Z

On Wed, 2004-01-07 at 10:54, David T Hollis wrote:
> 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:
>
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>