Re: Today Linus redesigns the networking driver interface (was Re: tulip driver in ...)

Linus Torvalds (torvalds@transmeta.com)
Sun, 20 Sep 1998 12:00:08 -0700 (PDT)


On Sun, 20 Sep 1998, Mr. James W. Laferriere wrote:
> >
> > Note that "dropping" was meant to be more generic than just dropping a
> > packet. We can decide to drop packets proactively by just deciding to
> > disable the interface completely for a while, to make sure it doesn't
> > flood us with interrupts. That's obviously fairly extreme, but it might be
> > the simplest answer (the driver could even decide on its own to disable
>
> I sure hope this would be a -last- ditch effort to prevent
> interupt flooding . In my router I sure wouldn't want this
> to be a -os- made decision I'd definatly would want me to be
> able to turn it off or on as I see needed .

Obviously, yes. It's more a matter of "we know we can't keep up anyway, so
let's drop pro-actively and get some real work done instead of just
dropping after the fact and not having any CPU time left for anything
else".

And before dropping, we should just try to tell the source to not send as
fast. I didn't even know that there was a protocol for doing that on an
ethernet level. Becker is right that that's the obvious first thing to do.

And finally, again, it should hopefully be equally obvious that the
_first_ objective should always be to be fast enough to not have to drop
in the first place. Dropping is bad. It's just that dropping and being
dead about it is even worse ;)

Linus

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