Larry McVoy wrote:
Interesting data point. My test case is like this:
server
bind
listen
while (newsock = accept...)
transfer()
client
connect
transfer
If the server side is the source of the data, i.e, it's transfer is a
write loop, then I get the bad behaviour. If I switch them so the data
flows in the other direction, then it works, I go from about 14K pkt/sec
to 43K pkt/sec.
Can anyone else reproduce this? I can extract the test case from lmbench
so it is standalone but I suspect that any test case will do it. I'll
try with the one that John sent. Yup, s/read/write/ and s/write/read/
in his two files at the appropriate places and I get exactly the same
behaviour.
So is this a bug or intentional?
I have a more complex configuration & application, but I don't see this
problem in
my testing. Using e1000 nics and modern hardware I can set up a connection
between two machines and run 800+Mbps in both directions, or near line speed
in one direction if the other direction is mostly silent.
I am purposefully setting the socket send/rx buffers, as well has
twiddling with
the tcp and netdev related tunables. If you want, I can email these
tweaks to you.
NICs and busses have a huge impact on performance, so make sure those
are good.
Thanks,
Ben
--
Ben Greear <[EMAIL PROTECTED]>
Candela Technologies Inc http://www.candelatech.com
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
