Re: Q: (ab)using zerocopy for drivers with alignment contraints

["David S. Miller" <davem@xxxxxxxxxx>]

Manfred Spraul writes:
 > skb_copy_datagram & friends follow the fragment list. My function
 > doesn't/mustn't follow skb_shinfo(skb)->frag_list. Should I still call
 > it skb_copy_datagram{,_iovec}_kernel? I don't like functions with
 > similar names and subtile differences.

Why "mustn't it" follow the frag list?  I think it would be
"absolutely fantastic" if it did follow the frag list!  Then
we could optimize the forwarding of fragmented packets.

There is no subtle difference, make it do _exactly_ what
skb_copy_datagram{,_iovec}() does to userspace and name it
how I've asked you to name it.

What are you trying to avoid by not walking the frag_list?  A single
NULL pointer check?  Get real :-)

Later,
David S. Miller
davem@xxxxxxxxxx