interrupt routing problem?

Matthew Dillon dillon at apollo.backplane.com
Wed Feb 9 21:54:07 PST 2005


:I may have spoken too soon. It appears that I may have been trashing my
:(cheapo) switch, which caused an actual transmitter failure/device timeout. 
:The machine with dfly ran while I was at lunch without failing. In FreeBSD 4.9
:it locks up the transmitter in a minute or 2. I'm going to run it overnight. 
:
:I do have a question about my top measurements. Running the same test on 
:the same MB, In Dragonfly, I see about 8% system and 12% interrupt, but 
:FreeBSD 4.11 only shows 12%-14% interrrupt and 0% for system. Is freeBSD 
:not including cycles that Dfly is? Is this going to be like measuring a 
:beachball
:with a yardstick?

    That's like comparing apples with oranges.  It sounds about right,
    I would expect FreeBSD to handle packet routing entirely within the
    interrupt.  Right now I think Dragonfly is routing through the ethernet
    stack so it's getting messaged to a thread, and its going to stay that
    way for a while.  I wouldn't expect a 14% vs 20% difference in load but
    your earlier saturation tests seem to validate those numbers.

    Optimizing network throughput is not a priority for us right now, I 
    would be quite happy with a 14% vs 20% difference.  We are more focused
    on getting the implementation correct first, and optimizing it later.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>





More information about the Users mailing list