[net-next,v4,0/6] 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

Alexander Lobakin (4):
  net: skbuff: don't include <net/page_pool/types.h> to <linux/skbuff.h>
  page_pool: place frag_* fields in one cacheline
  net: skbuff: avoid accessing page_pool if !napi_safe when returning
    page
  net: skbuff: always try to recycle PP pages directly when in softirq

Jakub Kicinski (1):
  page_pool: add a lockdep check for recycling in hardirq

Yunsheng Lin (1):
  page_pool: split types and declarations from page_pool.h

 MAINTAINERS                                   |   2 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt.c     |   2 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c |   2 +-
 drivers/net/ethernet/engleder/tsnep_main.c    |   1 +
 drivers/net/ethernet/freescale/fec_main.c     |   1 +
 .../net/ethernet/hisilicon/hns3/hns3_enet.c   |   1 +
 .../net/ethernet/hisilicon/hns3/hns3_enet.h   |   2 +-
 drivers/net/ethernet/marvell/mvneta.c         |   2 +-
 drivers/net/ethernet/marvell/mvpp2/mvpp2.h    |   2 +-
 .../net/ethernet/marvell/mvpp2/mvpp2_main.c   |   1 +
 .../marvell/octeontx2/nic/otx2_common.c       |   1 +
 .../ethernet/marvell/octeontx2/nic/otx2_pf.c  |   1 +
 drivers/net/ethernet/mediatek/mtk_eth_soc.c   |   1 +
 drivers/net/ethernet/mediatek/mtk_eth_soc.h   |   2 +-
 .../ethernet/mellanox/mlx5/core/en/params.c   |   1 +
 .../net/ethernet/mellanox/mlx5/core/en/trap.c |   1 -
 .../net/ethernet/mellanox/mlx5/core/en/xdp.c  |   1 +
 .../net/ethernet/mellanox/mlx5/core/en_main.c |   2 +-
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   |   2 +-
 .../ethernet/mellanox/mlx5/core/en_stats.c    |   2 +-
 .../ethernet/microchip/lan966x/lan966x_fdma.c |   1 +
 .../ethernet/microchip/lan966x/lan966x_main.h |   2 +-
 drivers/net/ethernet/socionext/netsec.c       |   2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac.h  |   2 +-
 .../net/ethernet/stmicro/stmmac/stmmac_main.c |   1 +
 drivers/net/ethernet/ti/cpsw.c                |   2 +-
 drivers/net/ethernet/ti/cpsw_new.c            |   2 +-
 drivers/net/ethernet/ti/cpsw_priv.c           |   2 +-
 drivers/net/ethernet/wangxun/libwx/wx_lib.c   |   2 +-
 drivers/net/veth.c                            |   2 +-
 drivers/net/wireless/mediatek/mt76/mac80211.c |   1 -
 drivers/net/wireless/mediatek/mt76/mt76.h     |   1 +
 drivers/net/xen-netfront.c                    |   2 +-
 include/linux/lockdep.h                       |   7 +
 include/linux/skbuff.h                        |   5 +-
 .../net/{page_pool.h => page_pool/helpers.h}  | 242 +-----------------
 include/net/page_pool/types.h                 | 236 +++++++++++++++++
 include/trace/events/page_pool.h              |   2 +-
 net/bpf/test_run.c                            |   2 +-
 net/core/page_pool.c                          |  43 +---
 net/core/skbuff.c                             |  49 +++-
 net/core/xdp.c                                |   2 +-
 42 files changed, 335 insertions(+), 305 deletions(-)
 rename include/net/{page_pool.h => page_pool/helpers.h} (51%)
 create mode 100644 include/net/page_pool/types.h

---
From v3[2]:
* rebase again after the bpf-next merge ._.;
* #5: pick the Acked-by from Jesper.

From v2[3]:
* just rebase on top of Jakub's kdoc changes landed last minute.

From v1[4]:
* move the "avoid calling no-op DMA sync ops" piece out of the series --
  will join some other or transform into something else (Jakub et al.);
* #1: restore accidentally removed path in MAINTAINERS (Yunsheng);
* #1: prefer `include/net/page_pool/` over `include/net/page_pool/*` in
  MAINTAINERS (Yunsheng);
* #2: rename page_pool_return_skb_page() to napi_pp_put_page() -- the old
  name seems to not make any sense for some time already (Yunsheng);
* #2: guard napi_pp_put_page() with CONFIG_PAGE_POOL in skbuff.c (to not
  compile it when there are no users) (Yunsheng).

From RFC v2[5]:
* drop the dependency on the hybrid allocation series (and thus the
  "RFC" prefix) -- it wasn't a strict dep and it's not in the trees yet;
* add [slightly reworked] Yunsheng's patch which splits page_pool.h into
  2 headers -- merge conflict hell otherwise.
  Also fix a typo while nobody looks (Simon);
* #3 (former #2): word the commitmsg a bit better, mention the main
  reason for the change more clearly (Ilias);
* add Jakub's hardirq assertion as a prereq for the last patch;
* #9 (former #7): add comment mentioning that the hardirq case is not
  checked due to the assertion checking it later (yes, it is illegal to
  use Page Pool with the interrupts disabled or when in TH) (Jakub).

From RFC v1[6]:
* #1: move the entire function to skbuff.c, don't try to split it (Alex);
* #2-4: new;
* #5: use internal flags field added in #4 and don't modify driver-defined
  structure (Alex, Jakub);
* #6: new;
* drop "add new NAPI state" as a redundant complication;
* #7: replace the check for the new NAPI state to just in_softirq(), should
  be fine (Jakub).

[2] https://lore.kernel.org/netdev/20230803182038.2646541-1-aleksander.lobakin@intel.com
[3] https://lore.kernel.org/netdev/20230803164014.993838-1-aleksander.lobakin@intel.com
[4] https://lore.kernel.org/netdev/20230727144336.1646454-1-aleksander.lobakin@intel.com
[5] https://lore.kernel.org/netdev/20230714170853.866018-1-aleksander.lobakin@intel.com
[6] https://lore.kernel.org/netdev/20230629152305.905962-1-aleksander.lobakin@intel.com
  

On Fri, 2023-08-04 at 20:05 +0200, Alexander Lobakin wrote:
> 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
> 
> Alexander Lobakin (4):
>   net: skbuff: don't include <net/page_pool/types.h> to <linux/skbuff.h>
>   page_pool: place frag_* fields in one cacheline
>   net: skbuff: avoid accessing page_pool if !napi_safe when returning
>     page
>   net: skbuff: always try to recycle PP pages directly when in softirq
> 
> Jakub Kicinski (1):
>   page_pool: add a lockdep check for recycling in hardirq
> 
> Yunsheng Lin (1):
>   page_pool: split types and declarations from page_pool.h

So the series mostly looks good to me. My only concern would be with
path 5 since I am not sure why we are just throwing a WARN_ON when we
could just take action on the info to prevent the problem in the first
place. That said the change doesn't hurt anything as-is so I would be
good with us thinking about changing that as a follow-up.

Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
  

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri,  4 Aug 2023 20:05:23 +0200 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [net-next,v4,1/6] page_pool: split types and declarations from page_pool.h
    https://git.kernel.org/netdev/net-next/c/a9ca9f9ceff3
  - [net-next,v4,2/6] net: skbuff: don't include <net/page_pool/types.h> to <linux/skbuff.h>
    https://git.kernel.org/netdev/net-next/c/75eaf63ea7af
  - [net-next,v4,3/6] page_pool: place frag_* fields in one cacheline
    https://git.kernel.org/netdev/net-next/c/06d0fbdad612
  - [net-next,v4,4/6] net: skbuff: avoid accessing page_pool if !napi_safe when returning page
    https://git.kernel.org/netdev/net-next/c/5b899c33b3b8
  - [net-next,v4,5/6] page_pool: add a lockdep check for recycling in hardirq
    https://git.kernel.org/netdev/net-next/c/ff4e538c8c3e
  - [net-next,v4,6/6] net: skbuff: always try to recycle PP pages directly when in softirq
    https://git.kernel.org/netdev/net-next/c/4a36d0180c45

You are awesome, thank you!
  

From: Patchwork-Bot+netdevbpf <patchwork-bot+netdevbpf@kernel.org>
Date: Mon, 07 Aug 2023 20:20:23 +0000

> Hello:
> 
> This series was applied to netdev/net-next.git (main)
> by Jakub Kicinski <kuba@kernel.org>:

Just got back from the long weekend and saw that mail, nice :D Thanks!

> 
> On Fri,  4 Aug 2023 20:05:23 +0200 you wrote:
>> 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.
>>
>> [...]
> 
> Here is the summary with links:
>   - [net-next,v4,1/6] page_pool: split types and declarations from page_pool.h
>     https://git.kernel.org/netdev/net-next/c/a9ca9f9ceff3
>   - [net-next,v4,2/6] net: skbuff: don't include <net/page_pool/types.h> to <linux/skbuff.h>
>     https://git.kernel.org/netdev/net-next/c/75eaf63ea7af
>   - [net-next,v4,3/6] page_pool: place frag_* fields in one cacheline
>     https://git.kernel.org/netdev/net-next/c/06d0fbdad612
>   - [net-next,v4,4/6] net: skbuff: avoid accessing page_pool if !napi_safe when returning page
>     https://git.kernel.org/netdev/net-next/c/5b899c33b3b8
>   - [net-next,v4,5/6] page_pool: add a lockdep check for recycling in hardirq
>     https://git.kernel.org/netdev/net-next/c/ff4e538c8c3e
>   - [net-next,v4,6/6] net: skbuff: always try to recycle PP pages directly when in softirq
>     https://git.kernel.org/netdev/net-next/c/4a36d0180c45
> 
> You are awesome, thank you!

Thanks,
Olek