[PATCH v2 1/3] net/bonding: support Tx prepare

Chas Williams 3chas3 at gmail.com
Wed Sep 14 18:59:33 CEST 2022


On 9/13/22 20:46, fengchengwen wrote:
> 
> The main problem is hard to design a tx_prepare for bonding device:
> 1. as Chas Williams said, there maybe twice hash calc to get target slave
>     devices.
> 2. also more important, if the slave devices have changes(e.g. slave device
>     link down or remove), and if the changes happens between bond-tx-prepare and
>     bond-tx-burst, the output slave will changes, and this may lead to checksum
>     failed. (Note: a bond device with slave devices may from different vendors,
>     and slave devices may have different requirements, e.g. slave-A support calc
>     IPv4 pseudo-head automatic (no need driver pre-calc), but slave-B need driver
>     pre-calc).
> 
> Current design cover the above two scenarios by using in-place tx-prepare. and
> in addition, bond devices are not transparent to applications, I think it's a
> practical method to provide tx-prepare support in this way.
> 


I don't think you need to export an enable/disable routine for the use of
rte_eth_tx_prepare. It's safe to just call that routine, even if it isn't
implemented. You are just trading one branch in DPDK librte_eth_dev for a
branch in drivers/net/bonding.

I think you missed fixing tx_machine in 802.3ad support. We have been using
the following patch locally which I never got around to submitting.


 From a458654d68ff5144266807ef136ac3dd2adfcd98 Mon Sep 17 00:00:00 2001
From: "Charles (Chas) Williams" <chwillia at ciena.com>
Date: Tue, 3 May 2022 16:52:37 -0400
Subject: [PATCH] net/bonding: call rte_eth_tx_prepare before rte_eth_tx_burst

Some PMDs might require a call to rte_eth_tx_prepare before sending the
packets for transmission. Typically, the prepare step handles the VLAN
headers, but it may need to do other things.

Signed-off-by: Chas Williams <chwillia at ciena.com>
---
  drivers/net/bonding/rte_eth_bond_8023ad.c | 16 +++++++-
  drivers/net/bonding/rte_eth_bond_pmd.c    | 50 +++++++++++++++++++----
  2 files changed, 55 insertions(+), 11 deletions(-)

diff --git a/drivers/net/bonding/rte_eth_bond_8023ad.c b/drivers/net/bonding/rte_eth_bond_8023ad.c
index b3cddd8a20..0680be8c06 100644
--- a/drivers/net/bonding/rte_eth_bond_8023ad.c
+++ b/drivers/net/bonding/rte_eth_bond_8023ad.c
@@ -636,9 +636,15 @@ tx_machine(struct bond_dev_private *internals, uint16_t slave_id)
  			return;
  		}
  	} else {
-		uint16_t pkts_sent = rte_eth_tx_burst(slave_id,
+		uint16_t pkts_sent;
+		uint16_t nb_prep;
+
+		nb_prep = rte_eth_tx_prepare(slave_id,
  				internals->mode4.dedicated_queues.tx_qid,
  				&lacp_pkt, 1);
+		pkts_sent = rte_eth_tx_burst(slave_id,
+				internals->mode4.dedicated_queues.tx_qid,
+				&lacp_pkt, nb_prep);
  		if (pkts_sent != 1) {
  			rte_pktmbuf_free(lacp_pkt);
  			set_warning_flags(port, WRN_TX_QUEUE_FULL);
@@ -1371,9 +1377,15 @@ bond_mode_8023ad_handle_slow_pkt(struct bond_dev_private *internals,
  			}
  		} else {
  			/* Send packet directly to the slow queue */
-			uint16_t tx_count = rte_eth_tx_burst(slave_id,
+			uint16_t tx_count;
+			uint16_t nb_prep;
+
+			nb_prep = rte_eth_tx_prepare(slave_id,
  					internals->mode4.dedicated_queues.tx_qid,
  					&pkt, 1);
+			tx_count = rte_eth_tx_burst(slave_id,
+					internals->mode4.dedicated_queues.tx_qid,
+					&pkt, nb_prep);
  			if (tx_count != 1) {
  				/* reset timer */
  				port->rx_marker_timer = 0;
diff --git a/drivers/net/bonding/rte_eth_bond_pmd.c b/drivers/net/bonding/rte_eth_bond_pmd.c
index b305b6a35b..c27073e66f 100644
--- a/drivers/net/bonding/rte_eth_bond_pmd.c
+++ b/drivers/net/bonding/rte_eth_bond_pmd.c
@@ -602,8 +602,12 @@ bond_ethdev_tx_burst_round_robin(void *queue, struct rte_mbuf **bufs,
  	/* Send packet burst on each slave device */
  	for (i = 0; i < num_of_slaves; i++) {
  		if (slave_nb_pkts[i] > 0) {
-			num_tx_slave = rte_eth_tx_burst(slaves[i], bd_tx_q->queue_id,
+			uint16_t nb_prep;
+
+			nb_prep = rte_eth_tx_prepare(slaves[i], bd_tx_q->queue_id,
  					slave_bufs[i], slave_nb_pkts[i]);
+			num_tx_slave = rte_eth_tx_burst(slaves[i], bd_tx_q->queue_id,
+					slave_bufs[i], nb_prep);
  
  			/* if tx burst fails move packets to end of bufs */
  			if (unlikely(num_tx_slave < slave_nb_pkts[i])) {
@@ -628,6 +632,7 @@ bond_ethdev_tx_burst_active_backup(void *queue,
  {
  	struct bond_dev_private *internals;
  	struct bond_tx_queue *bd_tx_q;
+	uint16_t nb_prep;
  
  	bd_tx_q = (struct bond_tx_queue *)queue;
  	internals = bd_tx_q->dev_private;
@@ -635,8 +640,10 @@ bond_ethdev_tx_burst_active_backup(void *queue,
  	if (internals->active_slave_count < 1)
  		return 0;
  
-	return rte_eth_tx_burst(internals->current_primary_port, bd_tx_q->queue_id,
-			bufs, nb_pkts);
+	nb_prep = rte_eth_tx_prepare(internals->current_primary_port,
+				     bd_tx_q->queue_id, bufs, nb_pkts);
+	return rte_eth_tx_burst(internals->current_primary_port,
+				bd_tx_q->queue_id, bufs, nb_prep);
  }
  
  static inline uint16_t
@@ -935,6 +942,8 @@ bond_ethdev_tx_burst_tlb(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
  	}
  
  	for (i = 0; i < num_of_slaves; i++) {
+		uint16_t nb_prep;
+
  		rte_eth_macaddr_get(slaves[i], &active_slave_addr);
  		for (j = num_tx_total; j < nb_pkts; j++) {
  			if (j + 3 < nb_pkts)
@@ -951,8 +960,10 @@ bond_ethdev_tx_burst_tlb(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
  #endif
  		}
  
-		num_tx_total += rte_eth_tx_burst(slaves[i], bd_tx_q->queue_id,
+		nb_prep = rte_eth_tx_prepare(slaves[i], bd_tx_q->queue_id,
  				bufs + num_tx_total, nb_pkts - num_tx_total);
+		num_tx_total += rte_eth_tx_burst(slaves[i], bd_tx_q->queue_id,
+				bufs + num_tx_total, nb_prep);
  
  		if (num_tx_total == nb_pkts)
  			break;
@@ -1064,8 +1075,12 @@ bond_ethdev_tx_burst_alb(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
  	/* Send ARP packets on proper slaves */
  	for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
  		if (slave_bufs_pkts[i] > 0) {
-			num_send = rte_eth_tx_burst(i, bd_tx_q->queue_id,
+			uint16_t nb_prep;
+
+			nb_prep = rte_eth_tx_prepare(i, bd_tx_q->queue_id,
  					slave_bufs[i], slave_bufs_pkts[i]);
+			num_send = rte_eth_tx_burst(i, bd_tx_q->queue_id,
+					slave_bufs[i], nb_prep);
  			for (j = 0; j < slave_bufs_pkts[i] - num_send; j++) {
  				bufs[nb_pkts - 1 - num_not_send - j] =
  						slave_bufs[i][nb_pkts - 1 - j];
@@ -1088,8 +1103,12 @@ bond_ethdev_tx_burst_alb(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
  	/* Send update packets on proper slaves */
  	for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
  		if (update_bufs_pkts[i] > 0) {
-			num_send = rte_eth_tx_burst(i, bd_tx_q->queue_id, update_bufs[i],
+			uint16_t nb_prep;
+
+			nb_prep = rte_eth_tx_prepare(i, bd_tx_q->queue_id, update_bufs[i],
  					update_bufs_pkts[i]);
+			num_send = rte_eth_tx_burst(i, bd_tx_q->queue_id, update_bufs[i],
+					nb_prep);
  			for (j = num_send; j < update_bufs_pkts[i]; j++) {
  				rte_pktmbuf_free(update_bufs[i][j]);
  			}
@@ -1155,12 +1174,17 @@ tx_burst_balance(void *queue, struct rte_mbuf **bufs, uint16_t nb_bufs,
  
  	/* Send packet burst on each slave device */
  	for (i = 0; i < slave_count; i++) {
+		uint16_t nb_prep;
+
  		if (slave_nb_bufs[i] == 0)
  			continue;
  
-		slave_tx_count = rte_eth_tx_burst(slave_port_ids[i],
+		nb_prep = rte_eth_tx_prepare(slave_port_ids[i],
  				bd_tx_q->queue_id, slave_bufs[i],
  				slave_nb_bufs[i]);
+		slave_tx_count = rte_eth_tx_burst(slave_port_ids[i],
+				bd_tx_q->queue_id, slave_bufs[i],
+				nb_prep);
  
  		total_tx_count += slave_tx_count;
  
@@ -1243,8 +1267,12 @@ tx_burst_8023ad(void *queue, struct rte_mbuf **bufs, uint16_t nb_bufs,
  
  		if (rte_ring_dequeue(port->tx_ring,
  				     (void **)&ctrl_pkt) != -ENOENT) {
-			slave_tx_count = rte_eth_tx_burst(slave_port_ids[i],
+			uint16_t nb_prep;
+
+			nb_prep = rte_eth_tx_prepare(slave_port_ids[i],
  					bd_tx_q->queue_id, &ctrl_pkt, 1);
+			slave_tx_count = rte_eth_tx_burst(slave_port_ids[i],
+					bd_tx_q->queue_id, &ctrl_pkt, nb_prep);
  			/*
  			 * re-enqueue LAG control plane packets to buffering
  			 * ring if transmission fails so the packet isn't lost.
@@ -1322,8 +1350,12 @@ bond_ethdev_tx_burst_broadcast(void *queue, struct rte_mbuf **bufs,
  
  	/* Transmit burst on each active slave */
  	for (i = 0; i < num_of_slaves; i++) {
-		slave_tx_total[i] = rte_eth_tx_burst(slaves[i], bd_tx_q->queue_id,
+		uint16_t nb_prep;
+
+		nb_prep = rte_eth_tx_prepare(slaves[i], bd_tx_q->queue_id,
  					bufs, nb_pkts);
+		slave_tx_total[i] = rte_eth_tx_burst(slaves[i], bd_tx_q->queue_id,
+					bufs, nb_prep);
  
  		if (unlikely(slave_tx_total[i] < nb_pkts))
  			tx_failed_flag = 1;
-- 
2.30.2


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