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

From: Alexander H Duyck <redacted>
Date: Tue, 25 Jul 2023 08:47:46 -0700

On Tue, 2023-07-25 at 21:12 +0800, Yunsheng Lin wrote:

quoted

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 <redacted>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
CC: Alexander Lobakin <aleksander.lobakin@intel.com>

[...]

quoted

+/* 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