They should be independent in general, but they aren't when the particular
case of TCP/IPv4 is concerned.
> Zero copy sendfile() does not require HW checksum to do zero copy, right?
Wrong...
> If HW checksum is present, then you get some extra performance as a bonus.
You get zerocopy, yes. :-) No HW cksum, no zerocopy.
Don't let this stop you, however. It's always possible that other networking
stacks will eventually make use of SG while not requiring HW TCP/UDP cksums.
None of them do right now, but...
> (hmm, one could make SG mandatory and the devices that don't support it can
> implement it in their driver. Just an idea)
Not really, that way lies driver madness. The less complexity in the driver,
the better.
Ion
[starfire driver maintainer]
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