interrupt moderation for if_* [was: serious networking (em) ...]

[Dan Nelson]

In the last episode (Nov 20), Bjoern A. Zeeb said:
> On Fri, 19 Nov 2004, Jeremie Le Hen wrote:
> > >  Hi, Jeremie, how is this? To disable Interrupt Moderation,
> > >  sysctl hw.em?.int_throttle_valve=0.
> >
> > Great, I would have called it "int_throttle_ceil", but that's a
> > detail and my opinion is totally subjective.
> >
> > >  However, because this patch is just made now, it is not fully tested.
> >
> > I'll give it a try this weekend although I won't be able to make
> > performance mesurements.
> 
> when thinking about this could there be some "global" way for
> interrupt moderation; For if_sk there is this PR:
> http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/41220
> 
> something 'unique' to all NIC drivers would be good I guess ?

You need NIC support for it, just like checksum offloading.  And other
drivers offer more sysctls; fxp lets you choose the maximum delay and
maximum packets to hold before firing an interrupt.

-- 
	Dan Nelson
	dnelson at allantgroup.com