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From: Mina Almasry <almasrymina@google.com>
Date: Sat, 16 Dec 2023 14:10:29 -0800
Message-ID: <CAHS8izMcFWu7zSuX9q8QgVNLiOiE5RKsb_yh5LoTKA1K8FUu1w@mail.gmail.com>
Subject: Re: [RFC PATCH net-next v1 2/4] net: introduce abstraction for
 network memory
To: Jakub Kicinski <kuba@kernel.org>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, 
	Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, 
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On Fri, Dec 15, 2023 at 6:52=E2=80=AFPM Jakub Kicinski <kuba@kernel.org> wr=
ote:
>
> On Wed, 13 Dec 2023 18:05:25 -0800 Mina Almasry wrote:
> > +struct netmem {
> > +     union {
> > +             struct page page;
> > +
> > +             /* Stub to prevent compiler implicitly converting from pa=
ge*
> > +              * to netmem_t* and vice versa.
> > +              *
> > +              * Other memory type(s) net stack would like to support
> > +              * can be added to this union.
> > +              */
> > +             void *addr;
> > +     };
> > +};
>
> My mind went to something like:
>
> typedef unsigned long __bitwise netmem_ref;
>
> instead. struct netmem does not exist, it's a handle which has
> to be converted to a real type using a helper.

Sure thing I can do that. Is it better to do something like:

struct netmem_ref;

like in this patch:

https://lore.kernel.org/linux-mm/20221108194139.57604-1-torvalds@linux-foun=
dation.org/

Asking because checkpatch tells me not to add typedefs to the kernel,
but checkpatch can be ignored if you think it's OK.

Also with this approach I can't use container_of and I need to do a
cast, I assume that's fine.

--=20
Thanks,
Mina