[dpdk-stable] patch 'test/distributor: fix lcores statistics' 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 10/30/20. 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 2ceaaa8d33c635f5f9d56e5b4f20387d7a53b932 Mon Sep 17 00:00:00 2001
From: Lukasz Wojciechowski <l.wojciechow at partner.samsung.com>
Date: Sat, 17 Oct 2020 05:06:52 +0200
Subject: [PATCH] test/distributor: fix lcores statistics

[ upstream commit 2dfdfcb404493a781d152afbc85a2a8a5b90580b ]

Statistics of handled packets are cleared and read on main lcore,
while they are increased in workers handlers on different lcores.

Without synchronization occasionally showed invalid values.
This patch uses atomic mechanisms to synchronize.
Relaxed memory model is used.

Fixes: c3eabff124e6 ("distributor: add unit tests")

Signed-off-by: Lukasz Wojciechowski <l.wojciechow at partner.samsung.com>
Acked-by: David Hunt <david.hunt at intel.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
---
 app/test/test_distributor.c | 39 +++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/app/test/test_distributor.c b/app/test/test_distributor.c
index 62495a8c67..6e5bdc3f60 100644
--- a/app/test/test_distributor.c
+++ b/app/test/test_distributor.c
@@ -43,7 +43,8 @@ total_packet_count(void)
 {
 	unsigned i, count = 0;
 	for (i = 0; i < worker_idx; i++)
-		count += worker_stats[i].handled_packets;
+		count += __atomic_load_n(&worker_stats[i].handled_packets,
+				__ATOMIC_RELAXED);
 	return count;
 }
 
@@ -51,7 +52,10 @@ total_packet_count(void)
 static inline void
 clear_packet_count(void)
 {
-	memset(&worker_stats, 0, sizeof(worker_stats));
+	unsigned int i;
+	for (i = 0; i < RTE_MAX_LCORE; i++)
+		__atomic_store_n(&worker_stats[i].handled_packets, 0,
+			__ATOMIC_RELAXED);
 }
 
 /* this is the basic worker function for sanity test
@@ -129,7 +133,8 @@ sanity_test(struct worker_params *wp, struct rte_mempool *p)
 
 	for (i = 0; i < rte_lcore_count() - 1; i++)
 		printf("Worker %u handled %u packets\n", i,
-				worker_stats[i].handled_packets);
+			__atomic_load_n(&worker_stats[i].handled_packets,
+					__ATOMIC_RELAXED));
 	printf("Sanity test with all zero hashes done.\n");
 
 	/* pick two flows and check they go correctly */
@@ -154,7 +159,9 @@ sanity_test(struct worker_params *wp, struct rte_mempool *p)
 
 		for (i = 0; i < rte_lcore_count() - 1; i++)
 			printf("Worker %u handled %u packets\n", i,
-					worker_stats[i].handled_packets);
+				__atomic_load_n(
+					&worker_stats[i].handled_packets,
+					__ATOMIC_RELAXED));
 		printf("Sanity test with two hash values done\n");
 	}
 
@@ -180,7 +187,8 @@ sanity_test(struct worker_params *wp, struct rte_mempool *p)
 
 	for (i = 0; i < rte_lcore_count() - 1; i++)
 		printf("Worker %u handled %u packets\n", i,
-				worker_stats[i].handled_packets);
+			__atomic_load_n(&worker_stats[i].handled_packets,
+					__ATOMIC_RELAXED));
 	printf("Sanity test with non-zero hashes done\n");
 
 	rte_mempool_put_bulk(p, (void *)bufs, BURST);
@@ -272,12 +280,14 @@ handle_work_with_free_mbufs(void *arg)
 
 	num = rte_distributor_get_pkt(d, id, buf, NULL, 0);
 	while (!quit) {
-		worker_stats[id].handled_packets += num;
+		__atomic_fetch_add(&worker_stats[id].handled_packets, num,
+				__ATOMIC_RELAXED);
 		for (i = 0; i < num; i++)
 			rte_pktmbuf_free(buf[i]);
 		num = rte_distributor_get_pkt(d, id, buf, NULL, 0);
 	}
-	worker_stats[id].handled_packets += num;
+	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
+			__ATOMIC_RELAXED);
 	rte_distributor_return_pkt(d, id, buf, num);
 	return 0;
 }
@@ -347,7 +357,8 @@ handle_work_for_shutdown_test(void *arg)
 	/* wait for quit single globally, or for worker zero, wait
 	 * for zero_quit */
 	while (!quit && !(id == zero_id && zero_quit)) {
-		worker_stats[id].handled_packets += num;
+		__atomic_fetch_add(&worker_stats[id].handled_packets, num,
+				__ATOMIC_RELAXED);
 		num = rte_distributor_get_pkt(d, id, buf, NULL, 0);
 
 		if (num > 0) {
@@ -357,8 +368,9 @@ handle_work_for_shutdown_test(void *arg)
 		}
 		zero_id = __atomic_load_n(&zero_idx, __ATOMIC_ACQUIRE);
 	}
-	worker_stats[id].handled_packets += num;
 
+	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
+			__ATOMIC_RELAXED);
 	if (id == zero_id) {
 		rte_distributor_return_pkt(d, id, NULL, 0);
 
@@ -371,7 +383,8 @@ handle_work_for_shutdown_test(void *arg)
 		num = rte_distributor_get_pkt(d, id, buf, NULL, 0);
 
 		while (!quit) {
-			worker_stats[id].handled_packets += num;
+			__atomic_fetch_add(&worker_stats[id].handled_packets,
+					num, __ATOMIC_RELAXED);
 			num = rte_distributor_get_pkt(d, id, buf, NULL, 0);
 		}
 	}
@@ -437,7 +450,8 @@ sanity_test_with_worker_shutdown(struct worker_params *wp,
 
 	for (i = 0; i < rte_lcore_count() - 1; i++)
 		printf("Worker %u handled %u packets\n", i,
-				worker_stats[i].handled_packets);
+			__atomic_load_n(&worker_stats[i].handled_packets,
+					__ATOMIC_RELAXED));
 
 	if (total_packet_count() != BURST * 2) {
 		printf("Line %d: Error, not all packets flushed. "
@@ -497,7 +511,8 @@ test_flush_with_worker_shutdown(struct worker_params *wp,
 	zero_quit = 0;
 	for (i = 0; i < rte_lcore_count() - 1; i++)
 		printf("Worker %u handled %u packets\n", i,
-				worker_stats[i].handled_packets);
+			__atomic_load_n(&worker_stats[i].handled_packets,
+					__ATOMIC_RELAXED));
 
 	if (total_packet_count() != BURST) {
 		printf("Line %d: Error, not all packets flushed. "
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-10-28 10:35:17.568182056 +0000
+++ 0189-test-distributor-fix-lcores-statistics.patch	2020-10-28 10:35:11.800834381 +0000
@@ -1,8 +1,10 @@
-From 2dfdfcb404493a781d152afbc85a2a8a5b90580b Mon Sep 17 00:00:00 2001
+From 2ceaaa8d33c635f5f9d56e5b4f20387d7a53b932 Mon Sep 17 00:00:00 2001
 From: Lukasz Wojciechowski <l.wojciechow at partner.samsung.com>
 Date: Sat, 17 Oct 2020 05:06:52 +0200
 Subject: [PATCH] test/distributor: fix lcores statistics
 
+[ upstream commit 2dfdfcb404493a781d152afbc85a2a8a5b90580b ]
+
 Statistics of handled packets are cleared and read on main lcore,
 while they are increased in workers handlers on different lcores.
 
@@ -11,7 +13,6 @@
 Relaxed memory model is used.
 
 Fixes: c3eabff124e6 ("distributor: add unit tests")
-Cc: stable at dpdk.org
 
 Signed-off-by: Lukasz Wojciechowski <l.wojciechow at partner.samsung.com>
 Acked-by: David Hunt <david.hunt at intel.com>
@@ -21,7 +22,7 @@
  1 file changed, 27 insertions(+), 12 deletions(-)
 
 diff --git a/app/test/test_distributor.c b/app/test/test_distributor.c
-index ec1fe348ba..4343efed14 100644
+index 62495a8c67..6e5bdc3f60 100644
 --- a/app/test/test_distributor.c
 +++ b/app/test/test_distributor.c
 @@ -43,7 +43,8 @@ total_packet_count(void)