[dpdk-dev] [PATCH 2/2] net/mlx5: reduce unnecessary memory access
From: Ruifeng Wang <hidden>
Date: 2021-06-01 08:31:39
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
MR btree len is a constant during Rx replenish. Moved retrieve of the value out of loop to reduce data loads. Slight performance uplift was measured on N1SDP. Signed-off-by: Ruifeng Wang <redacted> --- drivers/net/mlx5/mlx5_rxtx_vec.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/mlx5/mlx5_rxtx_vec.c b/drivers/net/mlx5/mlx5_rxtx_vec.c
index d5af2d91ff..fc7e2a7f41 100644
--- a/drivers/net/mlx5/mlx5_rxtx_vec.c
+++ b/drivers/net/mlx5/mlx5_rxtx_vec.c@@ -95,6 +95,7 @@ mlx5_rx_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq) volatile struct mlx5_wqe_data_seg *wq = &((volatile struct mlx5_wqe_data_seg *)rxq->wqes)[elts_idx]; unsigned int i; + uint16_t btree_len; if (n >= rxq->rq_repl_thresh) { MLX5_ASSERT(n >= MLX5_VPMD_RXQ_RPLNSH_THRESH(q_n));
@@ -106,6 +107,8 @@ mlx5_rx_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq) rxq->stats.rx_nombuf += n; return; } + + btree_len = mlx5_mr_btree_len(&rxq->mr_ctrl.cache_bh); for (i = 0; i < n; ++i) { void *buf_addr;
@@ -119,8 +122,7 @@ mlx5_rx_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq) wq[i].addr = rte_cpu_to_be_64((uintptr_t)buf_addr + RTE_PKTMBUF_HEADROOM); /* If there's a single MR, no need to replace LKey. */ - if (unlikely(mlx5_mr_btree_len(&rxq->mr_ctrl.cache_bh) - > 1)) + if (unlikely(btree_len > 1)) wq[i].lkey = mlx5_rx_mb2mr(rxq, elts[i]); } rxq->rq_ci += n;
--
2.25.1