Re: Au1550 ethernet throughput low

[Clem Taylor <clem.taylor@gmail.com>]

On 7/14/05, jaypee@hotpop.com <jaypee@hotpop.com> wrote:
> Clem you said were using 2.6.11 was that a kernel.org kernel or one
> from linux-mips.org?

The source I'm using originated from http://www.linux-mips.org/. It
was checked out from the head of
':pserver:cvs@ftp.linux-mips.org:/home/cvs' on 2005.03.18. At the time
of checkout, the linux-mips tree was missing a 2.6.11 tag. The closest
tag was linux_2_6_11_rc5, but the code is 2.6.11.

I'm thinking about switching to 2.6.12 next week so I can get PCI
shutdown support.

> Clem sent me the output of a test. In which he is getting 11MBs
> I'm assuming the B is bytes in which case that is as near line rate as dammit.

Yeah, UDP is running at near line rate, but it does consume a bunch of
CPU. I'm running our 1550s at 492MHz, but I have to run the memory at
123MHz (DDR). I just ran the test again, here's what ttcp said:

udp recv on au1550
ttcp -u -r -s -n 16384 -l 32768 -A 32768 -v -b 262144 -f M
ttcp-r: buflen=32768, nbuf=16384, align=32768/0, port=5001,
sockbufsize=262144  udp
ttcp-r: 536608768 bytes in 44.72 real seconds = 11.44 MB/sec +++
ttcp-r: 536608768 bytes in 17.41 CPU seconds = 29.39 MB/cpu sec
ttcp-r: 16378 I/O calls, msec/call = 2.80, calls/sec = 366.21
ttcp-r: 0.1user 17.2sys 0:44real 38% 0i+0d 0maxrss 0+7pf 16344+13csw

udp xmit on au1550
ttcp -u -t -n 16384 -s -l 32768 -A 32768 -v -b 262144 -f M  gort
ttcp-t: buflen=32768, nbuf=16384, align=32768/0, port=5001,
sockbufsize=262144  udp
ttcp-t: 536870912 bytes in 44.76 real seconds = 11.44 MB/sec +++
ttcp-t: 536870912 bytes in 15.26 CPU seconds = 33.56 MB/cpu sec
ttcp-t: 16390 I/O calls, msec/call = 2.80, calls/sec = 366.14
ttcp-t: 0.1user 15.1sys 0:44real 34% 0i+0d 0maxrss 0+8pf 3272+10csw