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SubjectRe: SMC Etherpower II / EPIC/100 83C170
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Illuminati Primus <vermont@gate.net> writes:

> A unique feature is the ability to transfer just the header of received
> packets and wait for the driver to provide a buffer for the rest of the
> data. This enables a secure U-Net style direct-to-user-address-space
> receive routine.
> ...
> I think I remember reading David Miller saying something about how
> networking could be significantly sped up by minimizing the amount of data
> that has to be copied around... How much work would it take to do that
> with this card?
The problem with this is that the eepro100 doesn't do TCP/UDP checksums
in hardware. This means that some routine has to go over the data
once anyway and a checksum() and a copy+checksum() operation has ca
the same cost (it's memory bound, not CPU bound). So this this feature
would only help for unchecksummed UDP or non-checksummed other
network protocols. Both are not to commmon.

-Andi

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