packet loss in heavy network load under 2.4 kernel

Michael E Brown michael_e_brown at
Wed Aug 21 13:16:00 CDT 2002

On Tue, 20 Aug 2002, Bergs wrote:

> hi
> My kernel is 2.4.16.
> when I use th smartbit test device to test the performance of eepro100
> driver 1.23b version.
> I test it on a intel s220 server with two intel 82550PM chip network
> interface.The data flow  generated by smartbit device come into the NIC
> 1 and come out from NIC 2.
> when the data load is 25% of 100Mbps,bi-directional,64byte frame

Well, here is your problem. I suspect that you are killing the machine 
with small packets. Basically, you are generating a lot more interrupts 
than the machine can handle. Try your test with sane, real-world packet 
sizes. Something like 500byte or 1500byte would be better.

You may also try to see if either of the drivers for this card (eepro100 
and e100 drivers) support interrupt mitigation, as this might help.

> size,and the test duration is 60 second,the test result display that
> serious packet loss take place. when the duration decrease to 10
> second,the other test condition matain unchanged,no packet losss.
> I wonder whether the memory is out of use.


If you are interested in pursuing this issue, I would suggest that you 
take it up on the linux-net mailing list, as there are people there who 
would be a whole lot better equipped to help you, or possibly fix any bugs 
that might exist.

Michael Brown

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