[PATCH net-next 0/2] page_pool: allow direct bulk recycling

From: Alexander Lobakin
Date: Fri Mar 29 2024 - 12:56:09 EST


Previously, there was no reliable way to check whether it's safe to use
direct PP cache. The drivers were passing @allow_direct to the PP
recycling functions and that was it. Bulk recycling is used by
xdp_return_frame_bulk() on .ndo_xdp_xmit() frames completion where
the page origin is unknown, thus the direct recycling has never been
tried.
Now that we have at least 2 ways of checking if we're allowed to perform
direct recycling -- pool->p.napi (Jakub) and pool->cpuid (Lorenzo), we
can use them when doing bulk recycling as well. Just move that logic
from the skb core to the PP core and call it before
__page_pool_put_page() every time @allow_direct is false.
Under high .ndo_xdp_xmit() traffic load, the win is 2-3% Pps assuming
the sending driver uses xdp_return_frame_bulk() on Tx completion.

Alexander Lobakin (2):
page_pool: check for PP direct cache locality later
page_pool: try direct bulk recycling

include/linux/skbuff.h | 12 ++++----
net/core/page_pool.c | 38 ++++++++++++++++++++---
net/core/skbuff.c | 70 +++++++++++++-----------------------------
net/ipv4/esp4.c | 2 +-
net/ipv6/esp6.c | 2 +-
5 files changed, 63 insertions(+), 61 deletions(-)

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2.44.0