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From: Mina Almasry <almasrymina@google.com>
Date: Wed, 6 Mar 2024 08:51:18 -0800
Message-ID: <CAHS8izMEJHWAHVjaKu9ZpeWRj1TwoLkmY5tCtDYxdDReBV8=Dw@mail.gmail.com>
Subject: Re: [RFC PATCH net-next v6 09/15] memory-provider: dmabuf devmem
 memory provider
To: Pavel Begunkov <asml.silence@gmail.com>
Cc: David Wei <dw@davidwei.uk>, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, 
	linux-doc@vger.kernel.org, linux-alpha@vger.kernel.org, 
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On Wed, Mar 6, 2024 at 6:59=E2=80=AFAM Pavel Begunkov <asml.silence@gmail.c=
om> wrote:
>
> On 3/6/24 02:42, Mina Almasry wrote:
> > On Tue, Mar 5, 2024 at 6:28=E2=80=AFPM David Wei <dw@davidwei.uk> wrote=
:
> >>
> >> On 2024-03-04 18:01, Mina Almasry wrote:
> >>> +     if (pool->p.queue)
> >>> +             binding =3D READ_ONCE(pool->p.queue->binding);
> >>> +
> >>> +     if (binding) {
> >>> +             pool->mp_ops =3D &dmabuf_devmem_ops;
> >>> +             pool->mp_priv =3D binding;
> >>> +     }
> >>
> >> This is specific to TCP devmem. For ZC Rx we will need something more
> >> generic to let us pass our own memory provider backend down to the pag=
e
> >> pool.
> >>
> >> What about storing ops and priv void ptr in struct netdev_rx_queue
> >> instead? Then we can both use it.
> >
> > Yes, this is dmabuf specific, I was thinking you'd define your own
> > member of netdev_rx_queue, and then add something like this to
> > page_pool_init:
>
> That would be quite annoying, there are 3 expected users together
> with huge pages, each would need a field and check all others are
> disabled as you mentioned and so on. It should be cleaner to pass
> a generic {pp_ops,pp_private} pair instead.
>
> If header dependencies is a problem, you it can probably be
>
> struct pp_provider_param {
>         struct pp_ops ops;
>         void *private;
> };
>
> # netdev_rx_queue.h
>
> // definition is not included here
> struct pp_provider_params;
>
> struct netdev_rx_queue {
>         ...
>         struct pp_provider_params *pp_params;
> };
>

Seems very reasonable, will do! Thanks!

> --
> Pavel Begunkov


--=20
Thanks,
Mina