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| author | Tariq Toukan <tariqt@mellanox.com> | 2017-06-15 14:35:34 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-15 22:53:23 -0400 |
| commit | cc26a4908682698cafdb5bb917f19840aff1a149 (patch) | |
| tree | 5c5070735501da3d9e0dfaa334862f1fb53ae4eb | |
| parent | 9bcee89ac4dbafe77b7a2fc68c4a784358d6e4e4 (diff) | |
| download | linux-cc26a4908682698cafdb5bb917f19840aff1a149.tar.gz linux-cc26a4908682698cafdb5bb917f19840aff1a149.tar.bz2 linux-cc26a4908682698cafdb5bb917f19840aff1a149.zip | |
net/mlx4_en: Improve transmit CQ polling
Several small performance improvements in TX CQ polling,
including:
- Compiler branch predictor hints.
- Minimize variables scope.
- More proper check of cq type.
- Use boolean instead of int for a binary indication.
Performance tests:
Tested on ConnectX3Pro, Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz
Packet-rate tests for both regular stack and XDP use cases:
No noticeable gain, no degradation.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Cc: kernel-team@fb.com
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/en_tx.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index 37386abea54c..2d5e0da1de2f 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -402,8 +402,7 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, struct mlx4_cq *mcq = &cq->mcq; struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->type][cq->ring]; struct mlx4_cqe *cqe; - u16 index; - u16 new_index, ring_index, stamp_index; + u16 index, ring_index, stamp_index; u32 txbbs_skipped = 0; u32 txbbs_stamp = 0; u32 cons_index = mcq->cons_index; @@ -418,7 +417,7 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, u32 last_nr_txbb; u32 ring_cons; - if (!priv->port_up) + if (unlikely(!priv->port_up)) return true; netdev_txq_bql_complete_prefetchw(ring->tx_queue); @@ -433,6 +432,8 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, /* Process all completed CQEs */ while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK, cons_index & size) && (done < budget)) { + u16 new_index; + /* * make sure we read the CQE after we read the * ownership bit @@ -479,7 +480,6 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor; } - /* * To prevent CQ overflow we first update CQ consumer and only then * the ring consumer. @@ -492,7 +492,7 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, ACCESS_ONCE(ring->last_nr_txbb) = last_nr_txbb; ACCESS_ONCE(ring->cons) = ring_cons + txbbs_skipped; - if (ring->free_tx_desc == mlx4_en_recycle_tx_desc) + if (cq->type == TX_XDP) return done < budget; netdev_tx_completed_queue(ring->tx_queue, packets, bytes); @@ -504,6 +504,7 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, netif_tx_wake_queue(ring->tx_queue); ring->wake_queue++; } + return done < budget; } @@ -524,7 +525,7 @@ int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget) struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi); struct net_device *dev = cq->dev; struct mlx4_en_priv *priv = netdev_priv(dev); - int clean_complete; + bool clean_complete; clean_complete = mlx4_en_process_tx_cq(dev, cq, budget); if (!clean_complete) |