Re: [RFC 01/19] netmem: rename struct net_iov to struct netmem_desc

[Mina Almasry <almasrymina@google.com>]

On Mon, May 12, 2025 at 6:29 AM Byungchul Park <byungchul@sk.com> wrote:
>
> On Mon, May 12, 2025 at 02:11:13PM +0100, Pavel Begunkov wrote:
> > On 5/9/25 12:51, Byungchul Park wrote:
> > > To simplify struct page, the page pool members of struct page should be
> > > moved to other, allowing these members to be removed from struct page.
> > >
> > > Reuse struct net_iov for also system memory, that already mirrored the
> > > page pool members.
> > >
> > > Signed-off-by: Byungchul Park <byungchul@sk.com>
> > > ---
> > >   include/linux/skbuff.h                  |  4 +--
> > >   include/net/netmem.h                    | 20 ++++++------
> > >   include/net/page_pool/memory_provider.h |  6 ++--
> > >   io_uring/zcrx.c                         | 42 ++++++++++++-------------
> >
> > You're unnecessarily complicating it for yourself. It'll certainly
> > conflict with changes in the io_uring tree, and hence it can't
> > be taken normally through the net tree.
> >
> > Why are you renaming it in the first place? If there are good
>
> It's because the struct should be used for not only io vetor things but
> also system memory.  Current network code uses struct page as system
> memory descriptor but struct page fields for page pool will be gone.
>
> So I had to reuse struct net_iov and I thought renaming it made more
> sense.  It'd be welcome if you have better idea.
>

As I said in another thread, struct page should not embed struct
net_iov as-is. struct net_iov already has fields that are unrelated to
page (like net_iov_owner) and more will be added in the future.

I think what Matthew seems to agree with AFAIU in the other thread is
creating a new struct, struct netmem_desc, and having struct net_iov
embed netmem_desc.


-- 
Thanks,
Mina