[net-next,v2,0/3] support non-frag page for page_pool_alloc_frag()

Message

Yunsheng Lin May 29, 2023, 9:28 a.m. UTC

In [1] & [2], there are usecases for veth and virtio_net to
use frag support in page pool to reduce memory usage, and it
may request different frag size depending on the head/tail
room space for xdp_frame/shinfo and mtu/packet size. When the
requested frag size is large enough that a single page can not
be split into more than one frag, using frag support only have
performance penalty because of the extra frag count handling
for frag support.

So this patchset provides a way for user to fail back to non
frag page when a page is not able to hold two frags.

And PP_FLAG_PAGE_FRAG can be removed now, the extra benefit is
that driver does not need to handle the case for arch with
PAGE_POOL_DMA_USE_PP_FRAG_COUNT when using page_pool_alloc_frag()
API.

1. https://patchwork.kernel.org/project/netdevbpf/patch/[e-mail]/
2. https://patchwork.kernel.org/project/netdevbpf/patch/[e-mail]/

V2: Add patch to remove PP_FLAG_PAGE_FRAG flags and mention
    virtio_net usecase in the cover letter.
V1: Drop RFC tag and page_pool_frag patch

Yunsheng Lin (3):
  page_pool: unify frag page and non-frag page handling
  page_pool: support non-frag page for page_pool_alloc_frag()
  page_pool: remove PP_FLAG_PAGE_FRAG flag

 .../net/ethernet/hisilicon/hns3/hns3_enet.c   |  3 +-
 .../marvell/octeontx2/nic/otx2_common.c       |  2 +-
 .../net/ethernet/mellanox/mlx5/core/en_main.c |  2 +-
 drivers/net/wireless/mediatek/mt76/mac80211.c |  2 +-
 include/net/page_pool.h                       | 42 +++++++++++----
 net/core/page_pool.c                          | 52 +++++++++++--------
 net/core/skbuff.c                             |  2 +-
 7 files changed, 67 insertions(+), 38 deletions(-)