mbox series

[net-next,v1,0/2] introduce skb_frag_fill_page_desc()

Message ID 20230509114337.21005-1-linyunsheng@huawei.com
Headers
Series introduce skb_frag_fill_page_desc() |

Message

Yunsheng Lin May 9, 2023, 11:43 a.m. UTC 
  Most users use __skb_frag_set_page()/skb_frag_off_set()/
skb_frag_size_set() to fill the page desc for a skb frag.
It does not make much sense to calling __skb_frag_set_page()
without calling skb_frag_off_set(), as the offset may depend
on whether the page is head page or tail page, so add
skb_frag_fill_page_desc() to fill the page desc for a skb
frag.

In the future, we can make sure the page in the frag is
head page of compound page or a base page, if not, we
may warn about that and convert the tail page to head
page and update the offset accordingly, if we see a warning
about that, we also fix the caller to fill the head page
in the frag. when the fixing is done, we may remove the
warning and converting.

In this way, we can remove the compound_head() or use
page_ref_*() like the below case:
https://elixir.bootlin.com/linux/latest/source/net/core/page_pool.c#L881
https://elixir.bootlin.com/linux/latest/source/include/linux/skbuff.h#L3383

It may also convert net stack to use the folio easier.

RFC: remove a local variable as pointed out by Simon.

Yunsheng Lin (2):
  net: introduce and use skb_frag_fill_page_desc()
  net: remove __skb_frag_set_page()

 .../net/ethernet/aquantia/atlantic/aq_ring.c  |  6 +--
 drivers/net/ethernet/broadcom/bnx2.c          |  1 -
 drivers/net/ethernet/broadcom/bnxt/bnxt.c     | 10 ++---
 drivers/net/ethernet/chelsio/cxgb3/sge.c      |  5 +--
 drivers/net/ethernet/emulex/benet/be_main.c   | 32 ++++++++-------
 drivers/net/ethernet/freescale/enetc/enetc.c  |  5 +--
 .../net/ethernet/fungible/funeth/funeth_rx.c  |  5 +--
 drivers/net/ethernet/marvell/mvneta.c         |  5 +--
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   |  4 +-
 drivers/net/ethernet/sun/cassini.c            |  8 +---
 drivers/net/virtio_net.c                      |  4 +-
 drivers/net/vmxnet3/vmxnet3_drv.c             |  4 +-
 drivers/net/xen-netback/netback.c             |  4 +-
 include/linux/skbuff.h                        | 39 +++++--------------
 net/bpf/test_run.c                            |  3 +-
 net/core/gro.c                                |  4 +-
 net/core/pktgen.c                             | 13 ++++---
 net/core/skbuff.c                             |  7 ++--
 net/tls/tls_device.c                          | 10 ++---
 net/xfrm/xfrm_ipcomp.c                        |  5 +--
 20 files changed, 65 insertions(+), 109 deletions(-)

Comments

Jakub Kicinski May 10, 2023, 1 a.m. UTC | #1 
On Tue, 9 May 2023 19:43:35 +0800 Yunsheng Lin wrote:
> Most users use __skb_frag_set_page()/skb_frag_off_set()/
> skb_frag_size_set() to fill the page desc for a skb frag.
> It does not make much sense to calling __skb_frag_set_page()
> without calling skb_frag_off_set(), as the offset may depend
> on whether the page is head page or tail page, so add
> skb_frag_fill_page_desc() to fill the page desc for a skb
> frag.
> 
> In the future, we can make sure the page in the frag is
> head page of compound page or a base page, if not, we
> may warn about that and convert the tail page to head
> page and update the offset accordingly, if we see a warning
> about that, we also fix the caller to fill the head page
> in the frag. when the fixing is done, we may remove the
> warning and converting.
> 
> In this way, we can remove the compound_head() or use
> page_ref_*() like the below case:
> https://elixir.bootlin.com/linux/latest/source/net/core/page_pool.c#L881
> https://elixir.bootlin.com/linux/latest/source/include/linux/skbuff.h#L3383
> 
> It may also convert net stack to use the folio easier.
> 
> RFC: remove a local variable as pointed out by Simon.

Looks like you posted this 3 times and different people replied with
their acks to different versions :(

Wait awhile, read:
https://www.kernel.org/doc/html/next/process/maintainer-netdev.html
and repost with all the ack/review tags included.