[PATCH net-next 0/2] support non-frag page for page_pool_alloc_frag()

From: Yunsheng Lin
Date: Fri May 26 2023 - 05:28:35 EST

In [1], there is a use case 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.

PP_FLAG_PAGE_FRAG may be removed after this patchset, and
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/d3ae6bd3537fbce379382ac6a42f67e22f27ece2.1683896626.git.lorenzo@xxxxxxxxxx/

V1: Drop RFC tag and page_pool_frag patch

Yunsheng Lin (2):
page_pool: unify frag page and non-frag page handling
page_pool: support non-frag page for page_pool_alloc_frag()

include/net/page_pool.h | 38 ++++++++++++++++++++++++++------
net/core/page_pool.c | 48 +++++++++++++++++++++++++----------------
2 files changed, 61 insertions(+), 25 deletions(-)