On 5/6/2023 2:32 AM, lon...@linuxonhyperv.com wrote:
> From: Long Li <lon...@microsoft.com>
>
> When sending TX packets, we don't need a completion for every packet sent.
> If packets are sent in a series, the completion of the last packet can be
> used to indicate completion of all prior packets.
>
> Cc: sta...@dpdk.org
>
Hi Long,
Patch looks good to me, but I am not sure on the backport request.
This patch is an optimisation update and we tend to get only fixes to
stable trees.
LTS maintainers cc'ed for comment.
> Signed-off-by: Long Li <lon...@microsoft.com>
> ---
> Change log
> v2: rebased to dpdk-next-net
>
> drivers/net/mana/mana.h | 3 ++-
> drivers/net/mana/tx.c | 33 ++++++++++++++++++++++++++++++---
> 2 files changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/mana/mana.h b/drivers/net/mana/mana.h
> index b653e1dd82..be88537f1a 100644
> --- a/drivers/net/mana/mana.h
> +++ b/drivers/net/mana/mana.h
> @@ -353,6 +353,7 @@ struct mana_priv {
> struct mana_txq_desc {
> struct rte_mbuf *pkt;
> uint32_t wqe_size_in_bu;
> + bool suppress_tx_cqe;
> };
>
> struct mana_rxq_desc {
> @@ -401,7 +402,7 @@ struct mana_txq {
> /* desc_ring_head is where we put pending requests to ring,
> * completion pull off desc_ring_tail
> */
> - uint32_t desc_ring_head, desc_ring_tail;
> + uint32_t desc_ring_head, desc_ring_tail, desc_ring_len;
>
> struct mana_mr_btree mr_btree;
> struct mana_stats stats;
> diff --git a/drivers/net/mana/tx.c b/drivers/net/mana/tx.c
> index 7f570181ad..5947efbe8d 100644
> --- a/drivers/net/mana/tx.c
> +++ b/drivers/net/mana/tx.c
> @@ -43,9 +43,11 @@ mana_stop_tx_queues(struct rte_eth_dev *dev)
>
> txq->desc_ring_tail =
> (txq->desc_ring_tail + 1) % txq->num_desc;
> + txq->desc_ring_len--;
> }
> txq->desc_ring_head = 0;
> txq->desc_ring_tail = 0;
> + txq->desc_ring_len = 0;
>
> memset(&txq->gdma_sq, 0, sizeof(txq->gdma_sq));
> memset(&txq->gdma_cq, 0, sizeof(txq->gdma_cq));
> @@ -173,13 +175,14 @@ mana_tx_burst(void *dpdk_txq, struct rte_mbuf
> **tx_pkts, uint16_t nb_pkts)
> int ret;
> void *db_page;
> uint16_t pkt_sent = 0;
> - uint32_t num_comp;
> + uint32_t num_comp, i;
>
> /* Process send completions from GDMA */
> num_comp = gdma_poll_completion_queue(&txq->gdma_cq,
> txq->gdma_comp_buf, txq->num_desc);
>
> - for (uint32_t i = 0; i < num_comp; i++) {
> + i = 0;
> + while (i < num_comp) {
> struct mana_txq_desc *desc =
> &txq->desc_ring[txq->desc_ring_tail];
> struct mana_tx_comp_oob *oob = (struct mana_tx_comp_oob *)
> @@ -204,7 +207,16 @@ mana_tx_burst(void *dpdk_txq, struct rte_mbuf **tx_pkts,
> uint16_t nb_pkts)
>
> desc->pkt = NULL;
> txq->desc_ring_tail = (txq->desc_ring_tail + 1) % txq->num_desc;
> + txq->desc_ring_len--;
> txq->gdma_sq.tail += desc->wqe_size_in_bu;
> +
> + /* If TX CQE suppression is used, don't read more CQE but move
> + * on to the next packet
> + */
> + if (desc->suppress_tx_cqe)
> + continue;
> +
> + i++;
> }
>
> /* Post send requests to GDMA */
> @@ -215,6 +227,9 @@ mana_tx_burst(void *dpdk_txq, struct rte_mbuf **tx_pkts,
> uint16_t nb_pkts)
> struct one_sgl sgl;
> uint16_t seg_idx;
>
> + if (txq->desc_ring_len >= txq->num_desc)
> + break;
> +
> /* Drop the packet if it exceeds max segments */
> if (m_pkt->nb_segs > priv->max_send_sge) {
> DP_LOG(ERR, "send packet segments %d exceeding max",
> @@ -310,7 +325,6 @@ mana_tx_burst(void *dpdk_txq, struct rte_mbuf **tx_pkts,
> uint16_t nb_pkts)
> tx_oob.short_oob.tx_compute_UDP_checksum = 0;
> }
>
> - tx_oob.short_oob.suppress_tx_CQE_generation = 0;
> tx_oob.short_oob.VCQ_number = txq->gdma_cq.id;
>
> tx_oob.short_oob.VSQ_frame_num =
> @@ -362,6 +376,16 @@ mana_tx_burst(void *dpdk_txq, struct rte_mbuf **tx_pkts,
> uint16_t nb_pkts)
> if (seg_idx != m_pkt->nb_segs)
> continue;
>
> + /* If we can at least queue post two WQEs and there are at
> + * least two packets to send, use TX CQE suppression for the
> + * current WQE
> + */
> + if (txq->desc_ring_len + 1 < txq->num_desc &&
> + pkt_idx + 1 < nb_pkts)
> + tx_oob.short_oob.suppress_tx_CQE_generation = 1;
> + else
> + tx_oob.short_oob.suppress_tx_CQE_generation = 0;
> +
> struct gdma_work_request work_req;
> uint32_t wqe_size_in_bu;
>
> @@ -384,8 +408,11 @@ mana_tx_burst(void *dpdk_txq, struct rte_mbuf **tx_pkts,
> uint16_t nb_pkts)
> /* Update queue for tracking pending requests */
> desc->pkt = m_pkt;
> desc->wqe_size_in_bu = wqe_size_in_bu;
> + desc->suppress_tx_cqe =
> + tx_oob.short_oob.suppress_tx_CQE_generation;
> txq->desc_ring_head =
> (txq->desc_ring_head + 1) % txq->num_desc;
> + txq->desc_ring_len++;
>
> pkt_sent++;
>
