[PATCH v1 net-next 02/15] net: Introduce direct data placement tcp offload

[Jonathan Lemon]

On Fri, Dec 11, 2020 at 12:59:52PM -0700, David Ahern wrote:
> On 12/11/20 11:45 AM, Jakub Kicinski wrote:
> > Ack, these patches are not exciting (to me), so I'm wondering if there
> > is a better way. The only reason NIC would have to understand a ULP for
> > ZC is to parse out header/message lengths. There's gotta be a way to
> > pass those in header options or such...
> > 
> > And, you know, if we figure something out - maybe we stand a chance
> > against having 4 different zero copy implementations (this, TCP,
> > AF_XDP, netgpu) :(
> 
> AF_XDP is for userspace IP/TCP/packet handling.
> 
> netgpu is fundamentally kernel stack socket with zerocopy direct to
> userspace buffers. Yes, it has more complications like the process is
> running on a GPU, but essential characteristics are header / payload
> split, a kernel stack managed socket, and dedicated H/W queues for the
> socket and those are all common to what the nvme patches are doing. So,
> can we create a common framework for those characteristics which enables
> other use cases (like a more generic Rx zerocopy)?

AF_XDP could also be viewed as a special case of netgpu.
-- 
Jonathan