Re: zero-copy TCP fileserving

Artur Skawina (skawina@geocities.com)
Thu, 03 Jun 1999 19:09:47 +0200


Bjorn Wesen wrote:
>
> > no, Richard is right - on modern cpus the additional writes don't slow
> > you down that much (eg on pii - only ~7% for fullsized eth frames).

> no CPU in the world has memory writes for free! i'll rephrase if its

from the cpus pov - some can (almost) do them for free; in certain cases.
(write posting, caches etc). That does of course not mean the writes
are completely free, it only means the slowdown is (much) less than 100%.

> the sort of thinking that goes "it's not noticeable on a $500 CPU right
> now so we don't have to care" is what keeps M$ programs slow and intel
> rich.

how about "it's not noticeable on a $50 CPU right now"? :^)

[ note that I cheated a bit - the stock kernel 686 routines lose ~30%
while copying. Will post a patch soon. ]

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