Messages in this thread | | | Subject | Re: Problem with e100 driver and latency on different packet sizes | From | Mark Haverkamp <> | Date | 15 May 2003 13:11:46 -0700 |
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On Thu, 2003-05-15 at 10:31, Jonathan Brown wrote: > sounds like the cpu cycle saver > > check out networking/e100.txt
I had seen something similar in an application of mine. If I loaded the e100 module with BundleMax=1 I got the same results as using the eepro100 driver.
Mark.
> > On Thu, 2003-05-15 at 15:54, Corey Minyard wrote: > > I'm seeing an odd thing with the e100 driver. It seems to be this way > > with the 2.4 series and with 2.5.68, and I couldn't find anything with a > > search. > > > > I've attached a small program to measure latency of round-trip time on > > UDP. If I send 85-byte packets between two of my machines, I get 170us > > round-trip latency. If I send 86-byte packets, I get 1329us latency. > > This seems quite odd. If I test on the eepro100 driver, I get expected > > linear increase in round-trip time as the packet size increases, and it > > never gets close to 1300us. > > > > To run the program, do: > > > > ./ip_lat -s <port> > > > > on one machine to run the server, and then do > > > > ./ip_lat <server IP> <port> 1000 85 > > > > to send 1000 85-byte packets from another machine. Change the 85 to 86 > > to see the latency go up. > > > > -Corey
-- Mark Haverkamp <markh@osdl.org>
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