[dpdk-stable] patch 'net/i40e: remove compiler barrier from NEON Rx' 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 3cb647149999c8d2ba1e68ab64c74cfa0ef42215 Mon Sep 17 00:00:00 2001
From: Gavin Hu <gavin.hu at arm.com>
Date: Tue, 13 Aug 2019 18:43:31 +0800
Subject: [PATCH] net/i40e: remove compiler barrier from NEON Rx

[ upstream commit f1f0f39806d97a9a4d74d47ce7fb04e9b4943e08 ]

As packet length extraction code was simplified,the ordering
was not necessary any more.[1]

2% performance gain was measured on Marvell ThunderX2.
4.3% performance gain was measured on Ampere eMAG80

[1] http://mails.dpdk.org/archives/dev/2016-April/037529.html

Fixes: ae0eb310f253 ("net/i40e: implement vector PMD for ARM")

Signed-off-by: Gavin Hu <gavin.hu at arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
Reviewed-by: Steve Capper <steve.capper at arm.com>
---
 drivers/net/i40e/i40e_rxtx_vec_neon.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/i40e/i40e_rxtx_vec_neon.c b/drivers/net/i40e/i40e_rxtx_vec_neon.c
index 3fb7de2dbc..c2a85fcc20 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_neon.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c
@@ -336,9 +336,6 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 			rte_mbuf_prefetch_part2(rx_pkts[pos + 3]);
 		}
 
-		/* avoid compiler reorder optimization */
-		rte_compiler_barrier();
-
 		/* pkt 3,4 shift the pktlen field to be 16-bit aligned*/
 		uint32x4_t len3 = vshlq_u32(vreinterpretq_u32_u64(descs[3]),
 					    len_shl);
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-12-19 14:32:26.651347198 +0000
+++ 0008-net-i40e-remove-compiler-barrier-from-NEON-Rx.patch	2019-12-19 14:32:25.401283865 +0000
@@ -1,8 +1,10 @@
-From f1f0f39806d97a9a4d74d47ce7fb04e9b4943e08 Mon Sep 17 00:00:00 2001
+From 3cb647149999c8d2ba1e68ab64c74cfa0ef42215 Mon Sep 17 00:00:00 2001
 From: Gavin Hu <gavin.hu at arm.com>
 Date: Tue, 13 Aug 2019 18:43:31 +0800
 Subject: [PATCH] net/i40e: remove compiler barrier from NEON Rx
 
+[ upstream commit f1f0f39806d97a9a4d74d47ce7fb04e9b4943e08 ]
+
 As packet length extraction code was simplified,the ordering
 was not necessary any more.[1]
 
@@ -12,7 +14,6 @@
 [1] http://mails.dpdk.org/archives/dev/2016-April/037529.html
 
 Fixes: ae0eb310f253 ("net/i40e: implement vector PMD for ARM")
-Cc: stable at dpdk.org
 
 Signed-off-by: Gavin Hu <gavin.hu at arm.com>
 Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
@@ -22,10 +23,10 @@
  1 file changed, 3 deletions(-)
 
 diff --git a/drivers/net/i40e/i40e_rxtx_vec_neon.c b/drivers/net/i40e/i40e_rxtx_vec_neon.c
-index 5555e9b5cf..864eb9a325 100644
+index 3fb7de2dbc..c2a85fcc20 100644
 --- a/drivers/net/i40e/i40e_rxtx_vec_neon.c
 +++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c
-@@ -307,9 +307,6 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
+@@ -336,9 +336,6 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
  			rte_mbuf_prefetch_part2(rx_pkts[pos + 3]);
  		}