IRQ, network drivers, and the like...

[Chris Newton]

Yup, 30k interrupts/second.

  Well, I had a brief discussion with Donald Becker, who had written most of 
the linux network drivers, and he thought this was weird, and indicated a 
problem.  He thought the card(s) I was using should generate slightly less 
then the number of TX/RX packets/second.

  Problem is, after sending him some info, he seems to have dropped away for a 
while.  Likely on vacation or something... mmmmm.... vacation :)

  What are other people's experiences with the 3com 3c59x class of cards?  
Does 30K interrupts sound reasonable for 10K packets?

  Is this high?  IE: is this affecting system performance for other devices?  
Should I invest in a better card(s) with interrupt coallecing (sp?)?

Thanks

Chris


>===== Original Message From <carter at qosient.com> =====
>Hey Chris,
>   Do you mean interrupts per second?  I can understand how the
>card could generate (3 x (the number of packet)) interrupts.
>Start of bus transfer, end of bus transfer, and specific device
>handler interrupt, but this is just a guess, I don't really
>know.  Possibly Peter will have a real educated guess as to
>what is going on, and knowing him, possibly a way around it.
>
>Carter
>
>Carter Bullard
>QoSient, LLC
>300 E. 56th Street, Suite 18K
>New York, New York  10022
>
>carter at qosient.com
>Phone +1 212 588-9133
>Fax   +1 212 588-9134
>http://qosient.com
>
>> -----Original Message-----
>> From: Chris Newton [mailto:newton at unb.ca]
>> Sent: Tuesday, September 25, 2001 1:57 PM
>> To: carter at qosient.com
>> Subject: IRQ, network drivers, and the like...
>>
>>
>> Hi Carter,  how have you been?
>>
>>   I'm struggling with a weird problem and I thought maybe you
>> might have seen
>> this before, or be able to point me in the right direction.
>>
>>   One of the networks I'm watching (my big network), has (for
>> example), about
>> 5000 incoming packets and 5000 outgoing right now... works
>> out to about 2MB in
>> both directions.  That is fed into an argus box, via 1
>> cable... so, 10K
>> packets per second on the cable.
>>
>>   Whats weird.. is that right now, my network card is
>> generating about 26 to
>> 30,000 packets/second.  I feel this is bogging the machine...
>> and I dont know
>> why it might be doing that.  Argus is running, reading from
>> that interface.
>>
>>   The card is a 3Com, 3c980 (or something)... but, Im not
>> sure that matters...
>> because I swapped it for a intel etherner express pro, and I
>> had the same
>> problem... (even higher actually).  There is also an ra
>> client reading from
>> the localargus stream.
>>
>>   Weird.. but, do you have any ideas?
>>
>>