[dpdk-stable] patch 'net/bnxt: optimize Tx batching' has been queued to LTS release 18.11.3

[Kevin Traynor <ktraynor@redhat.com>]

Hi,

FYI, your patch has been queued to LTS release 18.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 06/26/19. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable-queue/commit/1227407bc832de51b3c43f34035e809ab090ed67

Thanks.

Kevin Traynor

---
From 1227407bc832de51b3c43f34035e809ab090ed67 Mon Sep 17 00:00:00 2001
From: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Date: Wed, 15 May 2019 11:08:16 -0700
Subject: [PATCH] net/bnxt: optimize Tx batching

[ upstream commit 220de9869bc3877bb493f6cccd96aabe98adeb6b ]

This patch adds a few optimizations to Tx batching. Instead of
specifying 'cmpl_next' to bnxt_start_xmit() as a hint to enable
completion for a given packet, request for completion on the last
successfully enqueued TxBD. This takes care of both success and
error cases. It eliminates 'cmpl_next' arg and related per-packet
condition checks around it.

Fixes: 5735eb241947 ("net/bnxt: support Tx batching")

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
---
 drivers/net/bnxt/bnxt_txr.c | 32 +++++++++-----------------------
 1 file changed, 9 insertions(+), 23 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_txr.c b/drivers/net/bnxt/bnxt_txr.c
index 52a926c02..82ab46501 100644
--- a/drivers/net/bnxt/bnxt_txr.c
+++ b/drivers/net/bnxt/bnxt_txr.c
@@ -122,5 +122,4 @@ static uint16_t bnxt_start_xmit(struct rte_mbuf *tx_pkt,
 				struct bnxt_tx_queue *txq,
 				uint16_t *coal_pkts,
-				uint16_t *cmpl_next,
 				struct tx_bd_long **last_txbd)
 {
@@ -185,10 +184,5 @@ static uint16_t bnxt_start_xmit(struct rte_mbuf *tx_pkt,
 	txbd->flags_type = nr_bds << TX_BD_LONG_FLAGS_BD_CNT_SFT;
 	txbd->flags_type |= TX_BD_SHORT_FLAGS_COAL_NOW;
-	if (!*cmpl_next) {
-		txbd->flags_type |= TX_BD_LONG_FLAGS_NO_CMPL;
-	} else {
-		*coal_pkts = 0;
-		*cmpl_next = false;
-	}
+	txbd->flags_type |= TX_BD_LONG_FLAGS_NO_CMPL;
 	txbd->len = tx_pkt->data_len;
 	if (tx_pkt->pkt_len >= 2014)
@@ -415,8 +409,8 @@ uint16_t bnxt_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 			       uint16_t nb_pkts)
 {
-	struct bnxt_tx_queue *txq = tx_queue;
+	int rc;
 	uint16_t nb_tx_pkts = 0;
 	uint16_t coal_pkts = 0;
-	uint16_t cmpl_next = 0;
+	struct bnxt_tx_queue *txq = tx_queue;
 	struct tx_bd_long *last_txbd = NULL;
 
@@ -432,25 +426,17 @@ uint16_t bnxt_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 	/* Handle TX burst request */
 	for (nb_tx_pkts = 0; nb_tx_pkts < nb_pkts; nb_tx_pkts++) {
-		int rc;
-
-		/* Request a completion on the last packet */
-		cmpl_next |= (nb_pkts == nb_tx_pkts + 1);
 		coal_pkts++;
 		rc = bnxt_start_xmit(tx_pkts[nb_tx_pkts], txq,
-				     &coal_pkts, &cmpl_next, &last_txbd);
+				     &coal_pkts, &last_txbd);
 
-		if (unlikely(rc)) {
-			/* Request a completion on the last successfully
-			 * enqueued packet
-			 */
-			if (last_txbd)
-				last_txbd->flags_type &=
-					~TX_BD_LONG_FLAGS_NO_CMPL;
+		if (unlikely(rc))
 			break;
-		}
 	}
 
-	if (nb_tx_pkts)
+	if (likely(nb_tx_pkts)) {
+		/* Request a completion on the last packet */
+		last_txbd->flags_type &= ~TX_BD_LONG_FLAGS_NO_CMPL;
 		B_TX_DB(txq->tx_ring->tx_doorbell, txq->tx_ring->tx_prod);
+	}
 
 	return nb_tx_pkts;
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-06-21 17:22:12.427357556 +0100
+++ 0013-net-bnxt-optimize-Tx-batching.patch	2019-06-21 17:22:11.721519171 +0100
@@ -1 +1 @@
-From 220de9869bc3877bb493f6cccd96aabe98adeb6b Mon Sep 17 00:00:00 2001
+From 1227407bc832de51b3c43f34035e809ab090ed67 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 220de9869bc3877bb493f6cccd96aabe98adeb6b ]
+
@@ -14 +15,0 @@
-Cc: stable@dpdk.org
@@ -23 +24 @@
-index 186934136..b15778b39 100644
+index 52a926c02..82ab46501 100644
@@ -44 +45 @@
-@@ -416,8 +410,8 @@ uint16_t bnxt_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+@@ -415,8 +409,8 @@ uint16_t bnxt_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
@@ -55 +56 @@
-@@ -433,25 +427,17 @@ uint16_t bnxt_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+@@ -432,25 +426,17 @@ uint16_t bnxt_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,