[PATCH] net/mlx5: poll completion queue once per a call
From: Yongseok Koh <hidden>
Date: 2017-07-20 15:48:50
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
mlx5_tx_complete() polls completion queue multiple times until it encounters an invalid entry. As Tx completions are suppressed by MLX5_TX_COMP_THRESH, it is waste of cycles to expect multiple completions in a poll. And freeing too many buffers in a call can cause high jitter. This patch improves throughput a little. Signed-off-by: Yongseok Koh <redacted> Acked-by: Nelio Laranjeiro <redacted> --- drivers/net/mlx5/mlx5_rxtx.h | 32 ++++++++++---------------------- 1 file changed, 10 insertions(+), 22 deletions(-)
diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 534aaeb46..7fd59a4b1 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h@@ -480,30 +480,18 @@ mlx5_tx_complete(struct txq *txq) struct rte_mempool *pool = NULL; unsigned int blk_n = 0; - do { - volatile struct mlx5_cqe *tmp; - - tmp = &(*txq->cqes)[cq_ci & cqe_cnt]; - if (check_cqe(tmp, cqe_n, cq_ci)) - break; - cqe = tmp; + cqe = &(*txq->cqes)[cq_ci & cqe_cnt]; + if (unlikely(check_cqe(cqe, cqe_n, cq_ci))) + return; #ifndef NDEBUG - if (MLX5_CQE_FORMAT(cqe->op_own) == MLX5_COMPRESSED) { - if (!check_cqe_seen(cqe)) - ERROR("unexpected compressed CQE, TX stopped"); - return; - } - if ((MLX5_CQE_OPCODE(cqe->op_own) == MLX5_CQE_RESP_ERR) || - (MLX5_CQE_OPCODE(cqe->op_own) == MLX5_CQE_REQ_ERR)) { - if (!check_cqe_seen(cqe)) - ERROR("unexpected error CQE, TX stopped"); - return; - } -#endif /* NDEBUG */ - ++cq_ci; - } while (1); - if (unlikely(cqe == NULL)) + if ((MLX5_CQE_OPCODE(cqe->op_own) == MLX5_CQE_RESP_ERR) || + (MLX5_CQE_OPCODE(cqe->op_own) == MLX5_CQE_REQ_ERR)) { + if (!check_cqe_seen(cqe)) + ERROR("unexpected error CQE, TX stopped"); return; + } +#endif /* NDEBUG */ + ++cq_ci; txq->wqe_pi = ntohs(cqe->wqe_counter); ctrl = (volatile struct mlx5_wqe_ctrl *) tx_mlx5_wqe(txq, txq->wqe_pi);
--
2.11.0