[dpdk-stable] patch 'net/ice: update writeback policy to reduce latency' has been queued to stable release 19.11.6

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.6

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/11/20. 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/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/d97dce73be24d6a4bdb1959cb24740a14a71e335

Thanks.

Luca Boccassi

---
>From d97dce73be24d6a4bdb1959cb24740a14a71e335 Mon Sep 17 00:00:00 2001
From: Jesse Brandeburg <jesse.brandeburg at intel.com>
Date: Fri, 23 Oct 2020 13:22:00 -0700
Subject: [PATCH] net/ice: update writeback policy to reduce latency

[ upstream commit 8b20510a042aee6681c33c20bb076b53cb354708 ]

Just like iavf, setting the value to 2us allows for generally good
streaming packet performance while keeping latency down, and
generally keeps the performance of the PF and VF interfaces similar.

The previous value of 0x10 was making latency on a single packet
receive be as much as 16us.

Fixes: 65dfc889d86b ("net/ice: support Rx queue interruption")

Reported-by: Brian Johnson <brian.johnson at intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg at intel.com>
Acked-by: Qi Zhang <qi.z.zhang at intel.com>
---
 drivers/net/ice/ice_ethdev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ice/ice_ethdev.c b/drivers/net/ice/ice_ethdev.c
index cb71d7bfd4..8acfce00aa 100644
--- a/drivers/net/ice/ice_ethdev.c
+++ b/drivers/net/ice/ice_ethdev.c
@@ -2633,7 +2633,7 @@ __vsi_queues_bind_intr(struct ice_vsi *vsi, uint16_t msix_vect,
 		PMD_DRV_LOG(INFO, "queue %d is binding to vect %d",
 			    base_queue + i, msix_vect);
 		/* set ITR0 value */
-		ICE_WRITE_REG(hw, GLINT_ITR(0, msix_vect), 0x10);
+		ICE_WRITE_REG(hw, GLINT_ITR(0, msix_vect), 0x2);
 		ICE_WRITE_REG(hw, QINT_RQCTL(base_queue + i), val);
 		ICE_WRITE_REG(hw, QINT_TQCTL(base_queue + i), val_tx);
 	}
-- 
2.27.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-11-09 18:40:13.207144288 +0000
+++ 0052-net-ice-update-writeback-policy-to-reduce-latency.patch	2020-11-09 18:40:11.183312091 +0000
@@ -1 +1 @@
-From 8b20510a042aee6681c33c20bb076b53cb354708 Mon Sep 17 00:00:00 2001
+From d97dce73be24d6a4bdb1959cb24740a14a71e335 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 8b20510a042aee6681c33c20bb076b53cb354708 ]
+
@@ -14 +15,0 @@
-Cc: stable at dpdk.org
@@ -24 +25 @@
-index 51b99c6506..3483f99897 100644
+index cb71d7bfd4..8acfce00aa 100644
@@ -27 +28 @@
-@@ -3345,7 +3345,7 @@ __vsi_queues_bind_intr(struct ice_vsi *vsi, uint16_t msix_vect,
+@@ -2633,7 +2633,7 @@ __vsi_queues_bind_intr(struct ice_vsi *vsi, uint16_t msix_vect,