From ad78af9b88f3d12134d6406468e7798e65c385c0 Mon Sep 17 00:00:00 2001 From: Tariq Toukan Date: Wed, 15 Feb 2017 17:05:39 +0200 Subject: [PATCH] net/mlx5e: Use prefetchw when a write is to follow "prefetchw()" prefetches the cacheline for write. Use it for skb->data, as soon we'll be copying the packet header there. Performance: Single-stream packet-rate tested with pktgen. Packets are dropped in tc level to zoom into driver data-path. Larger gain is expected for smaller packets, as less time is spent on handling SKB fragments, making the path shorter and the improvement more significant. --------------------------------------------- packet size | before | after | gain | 64B | 4,113,306 | 4,778,720 | 16% | 1024B | 3,633,819 | 3,950,593 | 8.7% | Signed-off-by: Tariq Toukan Cc: kernel-team@fb.com Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index d717573b73da..7b1566f0ae58 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -906,7 +906,7 @@ void mlx5e_handle_rx_cqe_mpwrq(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe) goto mpwrq_cqe_out; } - prefetch(skb->data); + prefetchw(skb->data); cqe_bcnt = mpwrq_get_cqe_byte_cnt(cqe); mlx5e_mpwqe_fill_rx_skb(rq, cqe, wi, cqe_bcnt, skb); -- 2.20.1