From: Yongseok Koh <yskoh@mellanox.com>
To: adrien.mazarguil@6wind.com, nelio.laranjeiro@6wind.com
Cc: dev@dpdk.org, Yongseok Koh <yskoh@mellanox.com>
Subject: [dpdk-dev] [PATCH] net/mlx5: poll completion queue once per a call
Date: Thu, 20 Jul 2017 08:48:35 -0700 [thread overview]
Message-ID: <20170720154835.13571-1-yskoh@mellanox.com> (raw)
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 <yskoh@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
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
next reply other threads:[~2017-07-20 15:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-20 15:48 Yongseok Koh [this message]
2017-07-20 16:34 ` Sagi Grimberg
2017-07-21 15:10 ` Yongseok Koh
2017-07-23 9:49 ` Sagi Grimberg
2017-07-25 7:43 ` Yongseok Koh
2017-07-27 11:12 ` Sagi Grimberg
2017-07-28 0:26 ` Yongseok Koh
2017-07-31 16:12 ` Ferruh Yigit
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