Too much data is uselessly written to the Tx doorbell.
Fixes: 1d88ba171942 ("net/mlx5: refactor Tx data path")
Signed-off-by: Nelio Laranjeiro <nelio.laranje...@6wind.com>
Acked-by: Adrien Mazarguil <adrien.mazarg...@6wind.com>
---
This patch should be applied on top of [1] or [2].
[1] http://dpdk.org/ml/archives/dev/2016-November/050716.html
[2] http://dpdk.org/dev/patchwork/patch/17254/
---
drivers/net/mlx5/mlx5_rxtx.c | 26 ++++++++++++--------------
drivers/net/mlx5/mlx5_rxtx.h | 2 --
drivers/net/mlx5/mlx5_txq.c | 2 --
3 files changed, 12 insertions(+), 18 deletions(-)
diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 22b22ac..029d872 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -82,7 +82,8 @@ txq_mp2mr(struct txq *txq, struct rte_mempool *mp)
__attribute__((always_inline));
static inline void
-mlx5_tx_dbrec(struct txq *txq) __attribute__((always_inline));
+mlx5_tx_dbrec(struct txq *txq, volatile struct mlx5_wqe *wqe)
+ __attribute__((always_inline));
static inline uint32_t
rxq_cq_to_pkt_type(volatile struct mlx5_cqe *cqe)
@@ -326,23 +327,20 @@ txq_mp2mr(struct txq *txq, struct rte_mempool *mp)
*
* @param txq
* Pointer to TX queue structure.
+ * @param wqe
+ * Pointer to the last WQE posted in the NIC.
*/
static inline void
-mlx5_tx_dbrec(struct txq *txq)
+mlx5_tx_dbrec(struct txq *txq, volatile struct mlx5_wqe *wqe)
{
- uint8_t *dst = (uint8_t *)((uintptr_t)txq->bf_reg + txq->bf_offset);
- uint32_t data[4] = {
- htonl((txq->wqe_ci << 8) | MLX5_OPCODE_SEND),
- htonl(txq->qp_num_8s),
- 0,
- 0,
- };
+ uint64_t *dst = (uint64_t *)((uintptr_t)txq->bf_reg);
+ volatile uint64_t *src = ((volatile uint64_t *)wqe);
+
rte_wmb();
*txq->qp_db = htonl(txq->wqe_ci);
/* Ensure ordering between DB record and BF copy. */
rte_wmb();
- memcpy(dst, (uint8_t *)data, 16);
- txq->bf_offset ^= (1 << txq->bf_buf_size);
+ *dst = *src;
}
/**
@@ -609,7 +607,7 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts,
uint16_t pkts_n)
txq->stats.opackets += i;
#endif
/* Ring QP doorbell. */
- mlx5_tx_dbrec(txq);
+ mlx5_tx_dbrec(txq, (volatile struct mlx5_wqe *)wqe);
txq->elts_head = elts_head;
return i;
}
@@ -816,7 +814,7 @@ mlx5_tx_burst_mpw(void *dpdk_txq, struct rte_mbuf **pkts,
uint16_t pkts_n)
/* Ring QP doorbell. */
if (mpw.state == MLX5_MPW_STATE_OPENED)
mlx5_mpw_close(txq, &mpw);
- mlx5_tx_dbrec(txq);
+ mlx5_tx_dbrec(txq, mpw.wqe);
txq->elts_head = elts_head;
return i;
}
@@ -1084,7 +1082,7 @@ mlx5_tx_burst_mpw_inline(void *dpdk_txq, struct rte_mbuf
**pkts,
mlx5_mpw_inline_close(txq, &mpw);
else if (mpw.state == MLX5_MPW_STATE_OPENED)
mlx5_mpw_close(txq, &mpw);
- mlx5_tx_dbrec(txq);
+ mlx5_tx_dbrec(txq, mpw.wqe);
txq->elts_head = elts_head;
return i;
}
diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 6dcd35d..e244c48 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -251,8 +251,6 @@ struct txq {
uint16_t elts_n:4; /* (*elts)[] length (in log2). */
uint16_t cqe_n:4; /* Number of CQ elements (in log2). */
uint16_t wqe_n:4; /* Number of of WQ elements (in log2). */
- uint16_t bf_buf_size:4; /* Log2 Blueflame size. */
- uint16_t bf_offset; /* Blueflame offset. */
uint16_t max_inline; /* Multiple of RTE_CACHE_LINE_SIZE to inline. */
uint32_t qp_num_8s; /* QP number shifted by 8. */
volatile struct mlx5_cqe (*cqes)[]; /* Completion queue. */
diff --git a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c
index f4c6682..ad39ddc 100644
--- a/drivers/net/mlx5/mlx5_txq.c
+++ b/drivers/net/mlx5/mlx5_txq.c
@@ -220,8 +220,6 @@ txq_setup(struct txq_ctrl *tmpl, struct txq_ctrl *txq_ctrl)
tmpl->txq.wqe_n = log2above(qp->sq.wqe_cnt);
tmpl->txq.qp_db = &qp->gen_data.db[MLX5_SND_DBR];
tmpl->txq.bf_reg = qp->gen_data.bf->reg;
- tmpl->txq.bf_offset = qp->gen_data.bf->offset;
- tmpl->txq.bf_buf_size = log2above(qp->gen_data.bf->buf_size);
tmpl->txq.cq_db = cq->dbrec;
tmpl->txq.cqes =
(volatile struct mlx5_cqe (*)[])
--
2.1.4
