[PATCH net-next 10/10] net/mlx4_en: Refactor mlx4_en_free_tx_desc
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STALE3408d
REVIEWED: 1 (0M)
From: Tariq Toukan <hidden>
Date: 2017-06-15 11:36:25
Subsystem:
mellanox ethernet driver (mlx4_en), mellanox mlx4 core vpi driver, networking drivers, the rest · Maintainers:
Tariq Toukan, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
1 review trailer.
Some code re-ordering, functionally equivalent. - The !tx_info->inl check is evaluated anyway in both flows (common case/end case). Run it first, this might finish the flows earlier. - dma_unmap calls are identical in both flows, get it out of the if block into the common area. Performance tests: Tested on ConnectX3Pro, Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz Gain is too small to be measurable, no degradation sensed. Results are similar for IPv4 and IPv6. Signed-off-by: Tariq Toukan <redacted> Reviewed-by: Saeed Mahameed <redacted> Cc: kernel-team@fb.com Cc: Eric Dumazet <redacted> --- drivers/net/ethernet/mellanox/mlx4/en_tx.c | 45 +++++++++++------------------- 1 file changed, 16 insertions(+), 29 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index efc4411b1e44..7d69d939ee2d 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c@@ -289,20 +289,20 @@ u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv, skb_tstamp_tx(skb, &hwts); } - /* Optimize the common case when there are no wraparounds */ - if (likely((void *)tx_desc + - (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) { - if (!tx_info->inl) { - if (tx_info->linear) - dma_unmap_single(priv->ddev, - tx_info->map0_dma, - tx_info->map0_byte_count, - PCI_DMA_TODEVICE); - else - dma_unmap_page(priv->ddev, - tx_info->map0_dma, - tx_info->map0_byte_count, - PCI_DMA_TODEVICE); + if (!tx_info->inl) { + if (tx_info->linear) + dma_unmap_single(priv->ddev, + tx_info->map0_dma, + tx_info->map0_byte_count, + PCI_DMA_TODEVICE); + else + dma_unmap_page(priv->ddev, + tx_info->map0_dma, + tx_info->map0_byte_count, + PCI_DMA_TODEVICE); + /* Optimize the common case when there are no wraparounds */ + if (likely((void *)tx_desc + + (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) { for (i = 1; i < nr_maps; i++) { data++; dma_unmap_page(priv->ddev,
@@ -310,23 +310,10 @@ u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv, be32_to_cpu(data->byte_count), PCI_DMA_TODEVICE); } - } - } else { - if (!tx_info->inl) { - if ((void *) data >= end) { + } else { + if ((void *)data >= end) data = ring->buf + ((void *)data - end); - } - if (tx_info->linear) - dma_unmap_single(priv->ddev, - tx_info->map0_dma, - tx_info->map0_byte_count, - PCI_DMA_TODEVICE); - else - dma_unmap_page(priv->ddev, - tx_info->map0_dma, - tx_info->map0_byte_count, - PCI_DMA_TODEVICE); for (i = 1; i < nr_maps; i++) { data++; /* Check for wraparound before unmapping */
--
1.8.3.1