[dpdk-stable] patch 'net/netvsc: avoid possible live lock' has been queued to stable release 19.11.3

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/21/20. 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.

Thanks.

Luca Boccassi

---
>From 4f880a2089d25f58ba93699b252334d6ef03b2f8 Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <stephen at networkplumber.org>
Date: Tue, 31 Mar 2020 10:14:04 -0700
Subject: [PATCH] net/netvsc: avoid possible live lock

[ upstream commit 36274f287103d2f4a372a99dff2c4f47eeb75633 ]

Since the ring buffer with host is shared for both transmit
completions and receive packets, it is possible that transmitter
could get starved if receive ring gets full.

Better to process all outstanding events which frees up transmit
buffer slots, even if means dropping some packets.

Fixes: 7e6c82430702 ("net/netvsc: avoid over filling Rx descriptor ring")

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 drivers/net/netvsc/hn_rxtx.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/netvsc/hn_rxtx.c b/drivers/net/netvsc/hn_rxtx.c
index cbdfcc628b..19f00a0528 100644
--- a/drivers/net/netvsc/hn_rxtx.c
+++ b/drivers/net/netvsc/hn_rxtx.c
@@ -1032,9 +1032,6 @@ retry:
 
 		if (tx_limit && tx_done >= tx_limit)
 			break;
-
-		if (rxq->rx_ring && rte_ring_full(rxq->rx_ring))
-			break;
 	}
 
 	if (bytes_read > 0)
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-05-19 14:04:46.488519011 +0100
+++ 0048-net-netvsc-avoid-possible-live-lock.patch	2020-05-19 14:04:44.184647792 +0100
@@ -1,8 +1,10 @@
-From 36274f287103d2f4a372a99dff2c4f47eeb75633 Mon Sep 17 00:00:00 2001
+From 4f880a2089d25f58ba93699b252334d6ef03b2f8 Mon Sep 17 00:00:00 2001
 From: Stephen Hemminger <stephen at networkplumber.org>
 Date: Tue, 31 Mar 2020 10:14:04 -0700
 Subject: [PATCH] net/netvsc: avoid possible live lock
 
+[ upstream commit 36274f287103d2f4a372a99dff2c4f47eeb75633 ]
+
 Since the ring buffer with host is shared for both transmit
 completions and receive packets, it is possible that transmitter
 could get starved if receive ring gets full.
@@ -11,7 +13,6 @@
 buffer slots, even if means dropping some packets.
 
 Fixes: 7e6c82430702 ("net/netvsc: avoid over filling Rx descriptor ring")
-Cc: stable at dpdk.org
 
 Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
 ---