IRQ, network drivers, and the like...

[Chris Newton]

\
  Ahh, could be.  Right, I likely just read it wrong. :)

 Chris

>===== Original Message From Peter Van Epp <vanepp at sfu.ca> =====
>	This doesn't seem to make any sense. The timer interrupt is a fixed
>interval (probably 18 per second). If the network is heavily loaded then
>the network card's interrupt rate will likely be far larger than that for the
>timer in normal operation unless I'm missing something. I expect what he is
>trying to say is that the timer interrupt is higher priority than the others
>and if it isn't incrementing, then something is disabling interrupts for too
>long and losing interrupts.
>
>Peter Van Epp / Operations and Technical Support
>Simon Fraser University, Burnaby, B.C. Canada
>
>>
>> Replying to my own message... love it :)
>>
>>   Anyways, heres another things that lends to the idea there might be a
>> problem:
>>
>> http://www.scyld.com/network/3c509.html
>> - some other device or device driver hogging the bus or disabling 
interrupts.
>> Check /proc/interrupts for excessive interrupt counts. The timer tick
>> interrupt should always be incrementing faster than the others.
>>
>> so, I check that...
>>           CPU0       CPU1
>>   0:     104885     102836    IO-APIC-edge  timer
>>   1:          0          3    IO-APIC-edge  keyboard
>>   2:          0          0          XT-PIC  cascade
>>  14:          2          2    IO-APIC-edge  ide0
>>  16:      58080      58093   IO-APIC-level  eth2
>>  20:    3395396    3396604   IO-APIC-level  eth0
>>  21:          0          0   IO-APIC-level  eth1
>>  30:       8004       7985   IO-APIC-level  aic7xxx
>>  31:     136694     136788   IO-APIC-level  aic7xxx
>>
>> in the 33 minutes this machine has been up, it has generated 6.6 Million
>> interrupts, versus the 206,000 on the timer....
>>
>>
>>   thats bad, no?
>>
>>
>> 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?
>> >>
>> >>
>>
>>