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| author | Maxim Mikityanskiy <maximmi@nvidia.com> | 2022-09-30 09:28:51 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-10-01 13:30:19 -0700 |
| commit | 5758c3145b88aa9d0919681a9d3edf39353f1dbd (patch) | |
| tree | 5cc1315c56b6f598ee1d59c61a6b4d0f22b5f9df /drivers/net/ethernet/mellanox/mlx5/core/en/params.c | |
| parent | a064c609849bf71adc7484b030539568cd2a5155 (diff) | |
| download | linux-stable-5758c3145b88aa9d0919681a9d3edf39353f1dbd.tar.gz linux-stable-5758c3145b88aa9d0919681a9d3edf39353f1dbd.tar.bz2 linux-stable-5758c3145b88aa9d0919681a9d3edf39353f1dbd.zip | |
net/mlx5e: Make the wqe_index_mask calculation more exact
The old calculation of wqe_index_mask may give false positives, i.e.
request bulking of pairs of WQEs when not strictly needed, for example,
when the first fragment size is equal to the PAGE_SIZE, bulking is not
needed, even if the number of fragments is odd.
Make the calculation more exact to cut false positives.
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlx5/core/en/params.c')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx5/core/en/params.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c index 49306a68b3b5..ac4d70bb21e8 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c @@ -648,7 +648,26 @@ static int mlx5e_build_rq_frags_info(struct mlx5_core_dev *mdev, * is not completed yet, WQE 2*N must not be allocated, as it's * responsible for allocating a new page. */ - info->wqe_index_mask = info->num_frags % 2; + if (frag_size_max == PAGE_SIZE) { + /* No WQE can start in the middle of a page. */ + info->wqe_index_mask = 0; + } else { + /* PAGE_SIZEs starting from 8192 don't use 2K-sized fragments, + * because there would be more than MLX5E_MAX_RX_FRAGS of them. + */ + WARN_ON(PAGE_SIZE != 2 * DEFAULT_FRAG_SIZE); + + /* Odd number of fragments allows to pack the last fragment of + * the previous WQE and the first fragment of the next WQE into + * the same page. + * As long as DEFAULT_FRAG_SIZE is 2048, and MLX5E_MAX_RX_FRAGS + * is 4, the last fragment can be bigger than the rest only if + * it's the fourth one, so WQEs consisting of 3 fragments will + * always share a page. + * When a page is shared, WQE bulk size is 2, otherwise just 1. + */ + info->wqe_index_mask = info->num_frags % 2; + } out: /* Bulking optimization to skip allocation until at least 8 WQEs can be |