Subject: Re: NetBSD and large pps
To: None <tech-net@netbsd.org>
From: Miles Nordin <carton@Ivy.NET>
List: tech-net
Date: 12/02/2004 22:30:42
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>>>>> "js" == Jonathan Stone <jonathan@dsg.stanford.edu> writes:

    js> what NAPI is

I think it is a FreeBSD 5.x feature.  Most people who use BSD routers,
ex. on the quagga list, buy NICs specifically to work with FreeBSD
NAPI.  When NAPI is working right, a heavily-loaded card generates
fewer interrupts than packets.

I think Linux and EnTee have some similar feechur where they switch to
polling mode on gigabit cards when under high load, then switch back
to interrupt if there is space between packets again.

    js> That said, you can get a dramatic increase in peak throughput
    js> by trading off for increased latency.

Great.  Where can we read about these sysctls?  It would help if you
were more specific.  You don't mention the name of the sysctl, what
versions of NetBSD have it, which driver it's in, what reasonoable
values to try would be, and where it's documented.

-- 
The auditing that is conducted on slot machine software in the U.S. is
significantly more meticulous than what is done to voting software.
		-- Bruce Schneier

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