Re: tuning for high connection rates

Adrian Chadd wrote:
On 05/12/2007, Philipp Wuensche <cryx-freebsd@xxxxxxx> wrote:

As I understand it, and correct me if I'm wrong, polling helps against
high interrupt rates but for that intel gigabit cards have interrupt
moderation. We don't have a problem with interrupts (20% CPU) at the
moment but with system (100% CPU) as you can see in the system
monitoring graphs. Interrupts sometimes peak at, but usually are under,
the 2k interrupts/sec limit.

Begin by reading up on the hardware profiling support (hwpmc, pmc,
etc) and see if you can get some system and process-specific profiling
information.

Oh interesting stuff, I definitely have to take a look into that. Nice.

Kernel/System profiling will probably show you an interesting thing or
two. One thing I noticed was high in my high-TCP-transaction tests
(but not on hardware anywhere near as nice as yours!) was crypto calls
for, IIRC, syncookies.

We tried with syncookies enabled and disabled, no change at all. But as
you already said, crypto calls on this kind of hardware are not that
expensive ;-)

greetings,
cryx

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