> It could be useful for applications like streaming video where other
> protocols on top provide additional functionality or in a multicast
> session where TCP migth not be appropriate.
sendfile on UDP would try to send gigabits per second over ppp0...
> But should not the 2.4.X kernels have support for chained sk_buffs (like
> the BSD mbufs) meaning that support for scatter-gatter I/O from the NIC
> should be unneccessary to support zero-copy (i.e., NO in-memory data
> copy operations)?
No clue what you mean over here. Zero copy means different things to
different people. Sendfile eliminates the 'read(to buffer);write(buffer to
network);' copy.
Some network drivers again may eliminate the 'copy_with_checksum()' step,
allowing minus-one-copy, in zerocopy reference frame.
Regards,
bert
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