On Tue, 2017-02-28 at 22:28 -0500, David Miller wrote: > These device are already choking, because as I stated this can already > be done via sendfile(). > > Networking card wise this isn't an issue, chips bring the entire packet > into their FIFO, compute checksums on the fly mid-stream, and then write > the 16-bit checksum field before starting to write the packet onto the > wire. > > I think this is completely a non-issue, and we thought about this right > from the start when sendfile() support was added nearly two decades ago. > If network cards from back then didn't crap out in this situation I > think the ones out there now are probably ok.
Well, we had to fix one issue with GSO fall back about 4 years ago. https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=cef401de7be8c4e155c6746bfccf721a4fa5fab9 So extra scrutiny would be nice. Zero copy is incredibly hard to get right.
