net/mlx5: fix instruction hotspot on replenishing Rx buffer

On replenishing Rx buffers for vectorized Rx, mbuf->buf_addr isn't needed
to be accessed as it is static and easily calculated from the mbuf address.
Accessing the mbuf content causes unnecessary load stall and it is worsened
on ARM.

Fixes: 545b884b1da3 ("net/mlx5: fix buffer address posting in SSE Rx")
Cc: stable@dpdk.org
Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
Acked-by: Shahaf Shuler <shahafs@mellanox.com>

diff --git a/drivers/net/mlx5/mlx5_rxtx_vec.h b/drivers/net/mlx5/mlx5_rxtx_vec.h
index fda7004e2d635e04441fa2addcdb568a8993b284..5df8e291e60a1dc2a336bfe83a23cd18332b8b83 100644 (file)
--- a/drivers/net/mlx5/mlx5_rxtx_vec.h
+++ b/drivers/net/mlx5/mlx5_rxtx_vec.h
@@ -102,7 +102,10 @@ mlx5_rx_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq, uint16_t n)
                return;
        }
        for (i = 0; i < n; ++i) {
-               wq[i].addr = rte_cpu_to_be_64((uintptr_t)elts[i]->buf_addr +
+               void *buf_addr = rte_mbuf_buf_addr(elts[i], rxq->mp);
+
+               assert(buf_addr == elts[i]->buf_addr);
+               wq[i].addr = rte_cpu_to_be_64((uintptr_t)buf_addr +
                                              RTE_PKTMBUF_HEADROOM);
                /* If there's only one MR, no need to replace LKey in WQE. */
                if (unlikely(mlx5_mr_btree_len(&rxq->mr_ctrl.cache_bh) > 1))