[dpdk-stable] patch 'net/cxgbe: fix prefetch for non-coalesced Tx packets' has been queued to LTS release 17.11.10

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to LTS release 17.11.10

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 12/21/19. 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.

Thanks.

Luca Boccassi

---
>From 6214aefb3c52a64a9a0e6da4506323f5eb683ab3 Mon Sep 17 00:00:00 2001
From: Rahul Lakkireddy <rahul.lakkireddy at chelsio.com>
Date: Sat, 28 Sep 2019 02:00:05 +0530
Subject: [PATCH] net/cxgbe: fix prefetch for non-coalesced Tx packets

[ upstream commit b1df19e43e1d1415ab7fae119e672a2f3b8f39f0 ]

Move prefetch code out of Tx coalesce path to allow prefetching for
non-coalesced Tx packets, as well.

Fixes: bf89cbedd2d9 ("cxgbe: optimize forwarding performance for 40G")

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy at chelsio.com>
---
 drivers/net/cxgbe/cxgbe_ethdev.c | 9 +++++++--
 drivers/net/cxgbe/sge.c          | 1 -
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/cxgbe/cxgbe_ethdev.c b/drivers/net/cxgbe/cxgbe_ethdev.c
index dc153c7312..8b5b9b4edb 100644
--- a/drivers/net/cxgbe/cxgbe_ethdev.c
+++ b/drivers/net/cxgbe/cxgbe_ethdev.c
@@ -91,6 +91,7 @@ static uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 	struct sge_eth_txq *txq = (struct sge_eth_txq *)tx_queue;
 	uint16_t pkts_sent, pkts_remain;
 	uint16_t total_sent = 0;
+	uint16_t idx = 0;
 	int ret = 0;
 
 	CXGBE_DEBUG_TX(adapter, "%s: txq = %p; tx_pkts = %p; nb_pkts = %d\n",
@@ -99,12 +100,16 @@ static uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 	t4_os_lock(&txq->txq_lock);
 	/* free up desc from already completed tx */
 	reclaim_completed_tx(&txq->q);
+	rte_prefetch0(rte_pktmbuf_mtod(tx_pkts[0], volatile void *));
 	while (total_sent < nb_pkts) {
 		pkts_remain = nb_pkts - total_sent;
 
 		for (pkts_sent = 0; pkts_sent < pkts_remain; pkts_sent++) {
-			ret = t4_eth_xmit(txq, tx_pkts[total_sent + pkts_sent],
-					  nb_pkts);
+			idx = total_sent + pkts_sent;
+			if ((idx + 1) < nb_pkts)
+				rte_prefetch0(rte_pktmbuf_mtod(tx_pkts[idx + 1],
+							volatile void *));
+			ret = t4_eth_xmit(txq, tx_pkts[idx], nb_pkts);
 			if (ret < 0)
 				break;
 		}
diff --git a/drivers/net/cxgbe/sge.c b/drivers/net/cxgbe/sge.c
index babff0b9b1..9dddea5324 100644
--- a/drivers/net/cxgbe/sge.c
+++ b/drivers/net/cxgbe/sge.c
@@ -1130,7 +1130,6 @@ out_free:
 				txq->stats.mapping_err++;
 				goto out_free;
 			}
-			rte_prefetch0((volatile void *)addr);
 			return tx_do_packet_coalesce(txq, mbuf, cflits, adap,
 						     pi, addr, nb_pkts);
 		} else {
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-12-19 14:32:27.773131736 +0000
+++ 0036-net-cxgbe-fix-prefetch-for-non-coalesced-Tx-packets.patch	2019-12-19 14:32:25.841292591 +0000
@@ -1,13 +1,14 @@
-From b1df19e43e1d1415ab7fae119e672a2f3b8f39f0 Mon Sep 17 00:00:00 2001
+From 6214aefb3c52a64a9a0e6da4506323f5eb683ab3 Mon Sep 17 00:00:00 2001
 From: Rahul Lakkireddy <rahul.lakkireddy at chelsio.com>
 Date: Sat, 28 Sep 2019 02:00:05 +0530
 Subject: [PATCH] net/cxgbe: fix prefetch for non-coalesced Tx packets
 
+[ upstream commit b1df19e43e1d1415ab7fae119e672a2f3b8f39f0 ]
+
 Move prefetch code out of Tx coalesce path to allow prefetching for
 non-coalesced Tx packets, as well.
 
 Fixes: bf89cbedd2d9 ("cxgbe: optimize forwarding performance for 40G")
-Cc: stable at dpdk.org
 
 Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy at chelsio.com>
 ---
@@ -16,10 +17,10 @@
  2 files changed, 7 insertions(+), 3 deletions(-)
 
 diff --git a/drivers/net/cxgbe/cxgbe_ethdev.c b/drivers/net/cxgbe/cxgbe_ethdev.c
-index 7d7be69edd..5d74f8ba3b 100644
+index dc153c7312..8b5b9b4edb 100644
 --- a/drivers/net/cxgbe/cxgbe_ethdev.c
 +++ b/drivers/net/cxgbe/cxgbe_ethdev.c
-@@ -67,6 +67,7 @@ uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+@@ -91,6 +91,7 @@ static uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
  	struct sge_eth_txq *txq = (struct sge_eth_txq *)tx_queue;
  	uint16_t pkts_sent, pkts_remain;
  	uint16_t total_sent = 0;
@@ -27,7 +28,7 @@
  	int ret = 0;
  
  	CXGBE_DEBUG_TX(adapter, "%s: txq = %p; tx_pkts = %p; nb_pkts = %d\n",
-@@ -75,12 +76,16 @@ uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+@@ -99,12 +100,16 @@ static uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
  	t4_os_lock(&txq->txq_lock);
  	/* free up desc from already completed tx */
  	reclaim_completed_tx(&txq->q);
@@ -47,10 +48,10 @@
  				break;
  		}
 diff --git a/drivers/net/cxgbe/sge.c b/drivers/net/cxgbe/sge.c
-index 641be96578..bf31902111 100644
+index babff0b9b1..9dddea5324 100644
 --- a/drivers/net/cxgbe/sge.c
 +++ b/drivers/net/cxgbe/sge.c
-@@ -1154,7 +1154,6 @@ out_free:
+@@ -1130,7 +1130,6 @@ out_free:
  				txq->stats.mapping_err++;
  				goto out_free;
  			}