[dpdk-stable] patch 'net/cxgbe: fix prefetch for non-coalesced Tx packets' has been queued to LTS release 18.11.6

[Kevin Traynor]

Hi,

FYI, your patch has been queued to LTS release 18.11.6

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 12/10/19. 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/6072887060f9efeec9fed1546220ca2a7f2597d0

Thanks.

Kevin.

---
>From 6072887060f9efeec9fed1546220ca2a7f2597d0 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 8926f8a29..5839a7bef 100644
--- a/drivers/net/cxgbe/cxgbe_ethdev.c
+++ b/drivers/net/cxgbe/cxgbe_ethdev.c
@@ -66,4 +66,5 @@ uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 	uint16_t pkts_sent, pkts_remain;
 	uint16_t total_sent = 0;
+	uint16_t idx = 0;
 	int ret = 0;
 
@@ -74,10 +75,14 @@ uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 	/* 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 ea28ea06c..172109c26 100644
--- a/drivers/net/cxgbe/sge.c
+++ b/drivers/net/cxgbe/sge.c
@@ -1153,5 +1153,4 @@ out_free:
 				goto out_free;
 			}
-			rte_prefetch0((volatile void *)addr);
 			return tx_do_packet_coalesce(txq, mbuf, cflits, adap,
 						     pi, addr, nb_pkts);
-- 
2.21.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-12-03 17:29:52.869695723 +0000
+++ 0018-net-cxgbe-fix-prefetch-for-non-coalesced-Tx-packets.patch	2019-12-03 17:29:51.719750599 +0000
@@ -1 +1 @@
-From b1df19e43e1d1415ab7fae119e672a2f3b8f39f0 Mon Sep 17 00:00:00 2001
+From 6072887060f9efeec9fed1546220ca2a7f2597d0 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit b1df19e43e1d1415ab7fae119e672a2f3b8f39f0 ]
+
@@ -10 +11,0 @@
-Cc: stable at dpdk.org
@@ -19 +20 @@
-index 7d7be69ed..5d74f8ba3 100644
+index 8926f8a29..5839a7bef 100644
@@ -22 +23 @@
-@@ -68,4 +68,5 @@ uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+@@ -66,4 +66,5 @@ uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
@@ -28 +29 @@
-@@ -76,10 +77,14 @@ uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+@@ -74,10 +75,14 @@ uint16_t cxgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
@@ -46 +47 @@
-index 641be9657..bf3190211 100644
+index ea28ea06c..172109c26 100644
@@ -49 +50 @@
-@@ -1155,5 +1155,4 @@ out_free:
+@@ -1153,5 +1153,4 @@ out_free: