On 11/02, Mina Almasry wrote:
Add skb_has_net_iovs(skb), assuming skb->unreadable and net_iov-backed
frags are equivalent for now (with a comment noting the two can be
decoupled in the future if readable net_iovs are introduced).
Also add skb_mem_provider_compat() and skb_frags_can_coalesce() so all
multi-skb coalescing, shifting, and GRO paths can share a single check
across pp_recycle, skb_zcopy(), and fragment memory providers:
- empty 0-length skbs are compatible without mixing readable payload
- page vs net_iov is rejected via skb_has_net_iovs() (0 pointer chases)
- page vs page is allowed via !skb_has_net_iovs() (0 pointer chases)
- net_iov vs net_iov compares mp_priv (walking frag_list if nr_frags is 0)
Maybe squash this and patch #4? Otherwise hard to follow :-(