net/mana: suppress TX CQE generation whenever possible
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Commit Message
From: Long Li <longli@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.
Signed-off-by: Long Li <longli@microsoft.com>
Cc: stable@dpdk.org
---
drivers/net/mana/mana.h | 3 ++-
drivers/net/mana/tx.c | 33 ++++++++++++++++++++++++++++++---
2 files changed, 32 insertions(+), 4 deletions(-)
@@ -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;
@@ -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) {
DRV_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++;