[dpdk-stable] patch 'latency: fix calculation for multi-thread' has been queued to stable release 19.11.1

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 02/13/20. 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 94047950e2b4887d5bf4be4073e6be37c3ae64c0 Mon Sep 17 00:00:00 2001
From: Reshma Pattan <reshma.pattan at intel.com>
Date: Thu, 5 Dec 2019 17:18:11 +0000
Subject: [PATCH] latency: fix calculation for multi-thread

[ upstream commit 2a178702c00f2a8b547358fedc7107d376f8825e ]

Make latency calculation multithread safe by
using spinlock.

Fixes: 5cd3cac9ed ("latency: added new library for latency stats")

Signed-off-by: Reshma Pattan <reshma.pattan at intel.com>
---
 lib/librte_latencystats/rte_latencystats.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/librte_latencystats/rte_latencystats.c b/lib/librte_latencystats/rte_latencystats.c
index 98e018939e..ba2fff3bcb 100644
--- a/lib/librte_latencystats/rte_latencystats.c
+++ b/lib/librte_latencystats/rte_latencystats.c
@@ -42,6 +42,7 @@ struct rte_latency_stats {
 	float avg_latency; /**< Average latency in nano seconds */
 	float max_latency; /**< Maximum latency in nano seconds */
 	float jitter; /** Latency variation */
+	rte_spinlock_t lock; /** Latency calculation lock */
 };
 
 static struct rte_latency_stats *glob_stats;
@@ -164,6 +165,7 @@ calc_latency(uint16_t pid __rte_unused,
 			latency[cnt++] = now - pkts[i]->timestamp;
 	}
 
+	rte_spinlock_lock(&glob_stats->lock);
 	for (i = 0; i < cnt; i++) {
 		/*
 		 * The jitter is calculated as statistical mean of interpacket
@@ -193,6 +195,7 @@ calc_latency(uint16_t pid __rte_unused,
 			alpha * (latency[i] - glob_stats->avg_latency);
 		prev_latency = latency[i];
 	}
+	rte_spinlock_unlock(&glob_stats->lock);
 
 	return nb_pkts;
 }
@@ -223,6 +226,7 @@ rte_latencystats_init(uint64_t app_samp_intvl,
 	}
 
 	glob_stats = mz->addr;
+	rte_spinlock_init(&glob_stats->lock);
 	samp_intvl = app_samp_intvl * latencystat_cycles_per_ns();
 
 	/** Register latency stats with stats library */
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-02-11 11:17:42.579087906 +0000
+++ 0108-latency-fix-calculation-for-multi-thread.patch	2020-02-11 11:17:38.572004563 +0000
@@ -1,13 +1,14 @@
-From 2a178702c00f2a8b547358fedc7107d376f8825e Mon Sep 17 00:00:00 2001
+From 94047950e2b4887d5bf4be4073e6be37c3ae64c0 Mon Sep 17 00:00:00 2001
 From: Reshma Pattan <reshma.pattan at intel.com>
 Date: Thu, 5 Dec 2019 17:18:11 +0000
 Subject: [PATCH] latency: fix calculation for multi-thread
 
+[ upstream commit 2a178702c00f2a8b547358fedc7107d376f8825e ]
+
 Make latency calculation multithread safe by
 using spinlock.
 
 Fixes: 5cd3cac9ed ("latency: added new library for latency stats")
-Cc: stable at dpdk.org
 
 Signed-off-by: Reshma Pattan <reshma.pattan at intel.com>
 ---