Re: excessive interrupts on network cards

[Benjamin LaHaise]

On Tue, Sep 25, 2001 at 06:38:31PM -0300, Chris Newton wrote:
> Yea, it is a single port card... I had meant to mention that in the email I 
> sent out...  ie: that it wasn't reporting correctly... but, I didnt really 
> think it was related, since the eepro was doing the same thing.
> 
>   As for comparing with ifconfig, I ran 'watch 1 ifconfig -a', and sure 
> enough, I have about ~7000-7500 packets coming in right now.  And, the 
> 'procinfo -D', reports ~21000-22000 interrupts per second.

This is heavily dependant on the interrupt mitigation features that a card  
has.  At least for the ns83820 driver, I'm testing a technique where the 
driver essentially switches to polled mode once the interrupt load goes 
above a certain threshold, thereby limiting the load to ~2500 irq/sec.  
Combined with carefully placed data prefetching, I'm seeing a huge increase 
in performance.  Of course, this comes at the expense of latency.

		-ben