The combination of the following condition was excluded from skb coalescing: from->pp_recycle = 1 from->cloned = 1 to->pp_recycle = 1 With page pool in use, this combination can be quite common(ex. NetworkMananger may lead to the additional packet_type being registered, thus the cloning). In scenarios with a higher number of small packets, it can significantly affect the success rate of coalescing. This patchset aims to optimize this scenario and enable coalescing of this particular combination. That also involves supporting multiple users referencing the same fragment of a pp page to accomondate the need to increment the "from" SKB page's pp page reference count. Changes from v8: - improve kdoc for skb_pp_frag_ref Liang Chen (4): page_pool: transition to reference count management after page draining page_pool: halve BIAS_MAX for multiple user references of a fragment skbuff: Add a function to check if a page belongs to page_pool skbuff: Optimization of SKB coalescing for page pool .../net/ethernet/mellanox/mlx5/core/en_rx.c | 4 +- include/linux/mm_types.h | 2 +- include/net/page_pool/helpers.h | 65 +++++++++++-------- include/net/page_pool/types.h | 6 +- net/core/page_pool.c | 14 ++-- net/core/skbuff.c | 50 ++++++++++---- 6 files changed, 89 insertions(+), 52 deletions(-) -- 2.31.1