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authorEric Dumazet <edumazet@google.com>2017-03-08 08:17:15 -0800
committerDavid S. Miller <davem@davemloft.net>2017-03-09 09:54:46 -0800
commit9e8c0395a7e87a8f0eb008297df25ffdf3e0e5b3 (patch)
tree8e6e651467966777a696c89841e885d429b7d855 /drivers
parentmlx4: add rx_alloc_pages counter in ethtool -S (diff)
downloadlinux-dev-9e8c0395a7e87a8f0eb008297df25ffdf3e0e5b3.tar.xz
linux-dev-9e8c0395a7e87a8f0eb008297df25ffdf3e0e5b3.zip
mlx4: do not access rx_desc from mlx4_en_process_rx_cq()
Instead of fetching dma address from rx_desc->data[0].addr, prefer using frags[0].dma + frags[0].page_offset to avoid a potential cache line miss. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Tariq Toukan <tariqt@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/ethernet/mellanox/mlx4/en_rx.c9
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index d3a425fa46b3..b62fa265890e 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -528,7 +528,6 @@ fail:
static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
- struct mlx4_en_rx_desc *rx_desc,
struct mlx4_en_rx_alloc *frags,
unsigned int length)
{
@@ -703,7 +702,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
struct mlx4_cqe *cqe;
struct mlx4_en_rx_ring *ring = priv->rx_ring[cq->ring];
struct mlx4_en_rx_alloc *frags;
- struct mlx4_en_rx_desc *rx_desc;
struct bpf_prog *xdp_prog;
int doorbell_pending;
struct sk_buff *skb;
@@ -738,7 +736,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
cq->mcq.cons_index & cq->size)) {
frags = ring->rx_info + (index << priv->log_rx_info);
- rx_desc = ring->buf + (index << ring->log_stride);
/*
* make sure we read the CQE after we read the ownership bit
@@ -767,7 +764,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
/* Get pointer to first fragment since we haven't
* skb yet and cast it to ethhdr struct
*/
- dma = be64_to_cpu(rx_desc->data[0].addr);
+ dma = frags[0].dma + frags[0].page_offset;
dma_sync_single_for_cpu(priv->ddev, dma, sizeof(*ethh),
DMA_FROM_DEVICE);
ethh = (struct ethhdr *)(page_address(frags[0].page) +
@@ -806,7 +803,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
void *orig_data;
u32 act;
- dma = be64_to_cpu(rx_desc->data[0].addr);
+ dma = frags[0].dma + frags[0].page_offset;
dma_sync_single_for_cpu(priv->ddev, dma,
priv->frag_info[0].frag_size,
DMA_FROM_DEVICE);
@@ -946,7 +943,7 @@ xdp_drop_no_cnt:
}
/* GRO not possible, complete processing here */
- skb = mlx4_en_rx_skb(priv, rx_desc, frags, length);
+ skb = mlx4_en_rx_skb(priv, frags, length);
if (unlikely(!skb)) {
ring->dropped++;
goto next;