Re: [PATCH v9 net-next 2/4] net: filter: split filter.h and expose eBPF to user space

[Daniel Borkmann <dborkman@redhat.com>]

On 10/14/2014 10:43 AM, Alexei Starovoitov wrote:
> On Tue, Oct 14, 2014 at 12:34 AM, Daniel Borkmann <dborkman@redhat.com> wrote:
>> On 10/13/2014 11:49 PM, Alexei Starovoitov wrote:
>>>
>>> On Mon, Oct 13, 2014 at 10:21 AM, Daniel Borkmann <dborkman@redhat.com>
>>> wrote:
>>>>
>>>> On 09/03/2014 05:46 PM, Daniel Borkmann wrote:
>>>> ...
>>>>>
>>>>> Ok, given you post the remaining two RFCs later on this window as
>>>>> you indicate, I have no objections:
>>>>>
>>>>> Acked-by: Daniel Borkmann <dborkman@redhat.com>
>>>>
>>>> Ping, Alexei, are you still sending the patch for bpf_common.h or
>>>> do you want me to take care of this?
>>>
>>> It's not forgotten.
>>> I'm not sending it only because net-next is closed
>>> and it seems to be -next material.
>>
>> Well, the point was since it's UAPI you're modifying, that it needs
>> to be shipped before it first gets exposed to user land ...
>>
>> I think that should be reason enough ... there's no point in doing
>> this at a later point in time.
>
> Moving common #defines from filter.h into bpf_common.h can
> be done at any point in time. For the sake of argument if
> there is an app that includes both filter.h and bpf.h, it will
> continue to work just fine.

Correct, but the argument was that we can _avoid_ this from the
very beginning. Thus, user space applications making use of eBPF
only need to include <linux/bpf.h>, nothing more.

Doing this at any later point in time will just lead to the need
to include both headers.