[PATCH v15 01/20] net: Introduce direct data placement tcp offload

[David Ahern]

On 9/21/23 1:43 AM, Aurelien Aptel wrote:
> David Ahern <dsahern at kernel.org> writes:
>> Not consolidating frags into linear is a requirement for any Rx ZC
>> solution (e.g., the gpu devmem RFC set and accompanying io_uring set for
>> userspace memory). Meaning, the bit can be more generic and less tied to
>> ulp_ddp.
> 
> In our view the ULP Direct Data Placement has a very specific design and
> avoiding skb coalescing is just one aspect of it.
> It would be hard to make it generic for any type of zero copy design. We
> can rename the bit to "ddp" or "zerocopy" if you prefer but it might end
> up being more misleading.

The number of single use case bits on sk_buff are piling up. In this
case, skb->ulp_ddp is only used to avoid skb_condense, so name it
accordingly. skb->no_condense for example.