net/mlx4_en: Avoid a cache line miss in TX completion for single frag skb's

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Add frag0_dma/frag0_byte_count into mlx4_en_tx_info to avoid a cache
line miss in TX completion for frames having one dma element.  (We avoid
reading back the tx descriptor)

Note this could be extended to 2/3 dma elements later, as we have free
room in mlx4_en_tx_info

Also, mlx4_en_free_tx_desc() no longer accesses skb_shinfo(). We use a
new nr_maps fields in mlx4_en_tx_info to avoid 2 or 3 cache misses.

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>

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Eric Dumazet 2014-10-05 12:35:13 +03:00 • committed by David S. Miller

parent dc9b06d156

commit 3d03641cb4

2 changed files with 49 additions and 37 deletions

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83

drivers/net/ethernet/mellanox/mlx4/en_tx.c

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3

drivers/net/ethernet/mellanox/mlx4/mlx4_en.h

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