From 29d40c903247596c954446639116467eb6689bb7 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 5 Oct 2014 12:35:14 +0300 Subject: [PATCH] net/mlx4_en: Use prefetch in tx path mlx4_en_free_tx_desc() uses a prefetchw(&skb->users) to speed up consume_skb() prefetchw(&ring->tx_queue->dql) to speed up BQL update Signed-off-by: Eric Dumazet Signed-off-by: Amir Vadai Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/en_tx.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index edc4a8810368..b96627c4972f 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -267,6 +268,11 @@ static u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv, int nr_maps = tx_info->nr_maps; int i; + /* We do not touch skb here, so prefetch skb->users location + * to speedup consume_skb() + */ + prefetchw(&skb->users); + if (unlikely(timestamp)) { struct skb_shared_hwtstamps hwts; @@ -385,6 +391,7 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, if (!priv->port_up) return true; + prefetchw(&ring->tx_queue->dql.limit); index = cons_index & size_mask; cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor; ring_index = ring->cons & size_mask; @@ -722,6 +729,8 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) } } + prefetchw(&ring->tx_queue->dql); + /* Track current inflight packets for performance analysis */ AVG_PERF_COUNTER(priv->pstats.inflight_avg, (u32) (ring->prod - ring->cons - 1)); -- 2.34.1