Re: [PATCH net-next v2] page_pool: split types and declarations from page_pool.h

[Alexander Lobakin]

From: Alexander H Duyck <alexander.duyck@xxxxxxxxx>
Date: Tue, 25 Jul 2023 08:47:46 -0700

> On Tue, 2023-07-25 at 21:12 +0800, Yunsheng Lin wrote:
>> Split types and pure function declarations from page_pool.h
>> and add them in page_pool/types.h, so that C sources can
>> include page_pool.h and headers should generally only include
>> page_pool/types.h as suggested by jakub.
>>
>> Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
>> Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx>
>> CC: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>

[...]

>> +/* Caller must provide appropriate safe context, e.g. NAPI. */
>> +void page_pool_update_nid(struct page_pool *pool, int new_nid);
>> +
>> +#endif /* _NET_PAGE_POOL_H */
> 
> 
> This seems kind of overkill for what is needed. It seems like the
> general thought process with splitting this was so that you had just
> the minimum of what is needed to support skbuff.h and the functions
> declared there. The rest of this would then be added via the .h to the
> .c files that will actually be calling the functions.
> 
> By that logic I think the only thing we really need is the function
> declaration for page_pool_return_skb_page moved into skbuff.h. We could
> then just remove page_pool.h from skbuff.h couldn't we?

This patch is not to drop page_pool.h include from skbuff.h.
This is more future-proof (since I'm dropping this include anyway in my
series) to have includes organized and prevent cases like that one with
skbuff.h from happening. And to save some CPU cycles on preprocessing if
that makes sense.

> 
> Another thing we could consider doing is looking at splitting things up
> so that we had a include file in net/core/page_pool.h to handle some of
> the cases where we are just linking the page_pool bits to other core
> file bits such as xdp.c and skbuff.c.

Thanks,
Olek