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authorEric Dumazet <edumazet@google.com>2014-10-05 12:35:14 +0300
committerDavid S. Miller <davem@davemloft.net>2014-10-06 01:04:15 -0400
commit29d40c903247596c954446639116467eb6689bb7 (patch)
treef7d83f93675d8011428428f673d9882f342fbdfc /drivers/net
parent3d03641cb4ea050f969dd3ab34113adb95287f36 (diff)
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 <edumazet@google.com> Signed-off-by: Amir Vadai <amirv@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ethernet/mellanox/mlx4/en_tx.c9
1 files changed, 9 insertions, 0 deletions
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 <linux/mlx4/qp.h>
#include <linux/skbuff.h>
#include <linux/if_vlan.h>
+#include <linux/prefetch.h>
#include <linux/vmalloc.h>
#include <linux/tcp.h>
#include <linux/ip.h>
@@ -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));