Merge branch 'page_pool-a-couple-of-assorted-optimizations'

Alexander Lobakin says:

====================
page_pool: a couple of assorted optimizations

That initially was a spin-off of the IAVF PP series[0], but has grown
(and shrunk) since then a bunch. In fact, it consists of three
semi-independent blocks:

* #1-2: Compile-time optimization. Split page_pool.h into 2 headers to
  not overbloat the consumers not needing complex inline helpers and
  then stop including it in skbuff.h at all. The first patch is also
  prereq for the whole series.
* #3: Improve cacheline locality for users of the Page Pool frag API.
* #4-6: Use direct cache recycling more aggressively, when it is safe
  obviously. In addition, make sure nobody wants to use Page Pool API
  with disabled interrupts.

Patches #1 and #5 are authored by Yunsheng and Jakub respectively, with
small modifications from my side as per ML discussions.
For the perf numbers for #3-6, please see individual commit messages.

Also available on my GH with many more Page Pool goodies[1].

[0] https://lore.kernel.org/netdev/20230530150035.1943669-1-aleksander.lobakin@intel.com
[1] https://github.com/alobakin/linux/commits/iavf-pp-frag
====================

Link: https://lore.kernel.org/r/20230804180529.2483231-1-aleksander.lobakin@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>