diff mbox series

[v7,06/16] test/distributor: synchronize lcores statistics

Message ID 20201010160508.19709-7-l.wojciechow@partner.samsung.com (mailing list archive)
State Superseded, archived
Delegated to: David Marchand
Headers
Series fix distributor synchronization issues |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Lukasz Wojciechowski Oct. 10, 2020, 4:04 p.m. UTC 
  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 acquire/release mechanisms to synchronize.

Fixes: c3eabff124e6 ("distributor: add unit tests")
Cc: bruce.richardson@intel.com
Cc: stable@dpdk.org

Signed-off-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
Acked-by: David Hunt <david.hunt@intel.com>
---
 app/test/test_distributor.c | 43 +++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 14 deletions(-)

Comments

Honnappa Nagarahalli Oct. 16, 2020, 5:13 a.m. UTC | #1 
Hi Lukasz,
	I see that in commit 8/16, the same code is changed again (updating the counters using the RELAXED memory order). It is better to pull the statistics changes from 8/16 into this commit.

Thanks,
Honnappa

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Lukasz Wojciechowski
> Sent: Saturday, October 10, 2020 11:05 AM
> To: David Hunt <david.hunt@intel.com>; Bruce Richardson
> <bruce.richardson@intel.com>
> Cc: dev@dpdk.org; l.wojciechow@partner.samsung.com; stable@dpdk.org
> Subject: [dpdk-dev] [PATCH v7 06/16] test/distributor: synchronize lcores
> statistics
> 
> 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 acquire/release mechanisms to synchronize.
> 
> Fixes: c3eabff124e6 ("distributor: add unit tests")
> Cc: bruce.richardson@intel.com
> Cc: stable@dpdk.org
> 
> Signed-off-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
> Acked-by: David Hunt <david.hunt@intel.com>
> ---
>  app/test/test_distributor.c | 43 +++++++++++++++++++++++++------------
>  1 file changed, 29 insertions(+), 14 deletions(-)
> 
> diff --git a/app/test/test_distributor.c b/app/test/test_distributor.c index
> 6cd7a2edd..838459392 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_ACQUIRE);
For ex: this line is changed in commit 8/16 as well. It is better to pull the changes from 8/16 to this commit.

>  	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_RELEASE);
>  }
> 
>  /* this is the basic worker function for sanity test @@ -69,13 +73,13 @@
> handle_work(void *arg)
>  	num = rte_distributor_get_pkt(db, id, buf, NULL, 0);
>  	while (!quit) {
>  		__atomic_fetch_add(&worker_stats[id].handled_packets,
> num,
> -				__ATOMIC_RELAXED);
> +				__ATOMIC_ACQ_REL);
>  		count += num;
>  		num = rte_distributor_get_pkt(db, id,
>  				buf, buf, num);
>  	}
>  	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
> -			__ATOMIC_RELAXED);
> +			__ATOMIC_ACQ_REL);
>  	count += num;
>  	rte_distributor_return_pkt(db, id, buf, num);
>  	return 0;
> @@ -131,7 +135,8 @@ 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_ACQUIRE));
>  	printf("Sanity test with all zero hashes done.\n");
> 
>  	/* pick two flows and check they go correctly */ @@ -156,7 +161,9
> @@ 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_ACQUIRE));
>  		printf("Sanity test with two hash values done\n");
>  	}
> 
> @@ -182,7 +189,8 @@ 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_ACQUIRE));
>  	printf("Sanity test with non-zero hashes done\n");
> 
>  	rte_mempool_put_bulk(p, (void *)bufs, BURST); @@ -275,14
> +283,16 @@ 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;
>  		count += num;
> +		__atomic_fetch_add(&worker_stats[id].handled_packets,
> num,
> +				__ATOMIC_ACQ_REL);
>  		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;
>  	count += num;
> +	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
> +			__ATOMIC_ACQ_REL);
>  	rte_distributor_return_pkt(d, id, buf, num);
>  	return 0;
>  }
> @@ -358,8 +368,9 @@ 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;
>  		count += num;
> +		__atomic_fetch_add(&worker_stats[id].handled_packets,
> num,
> +				__ATOMIC_ACQ_REL);
>  		for (i = 0; i < num; i++)
>  			rte_pktmbuf_free(buf[i]);
>  		num = rte_distributor_get_pkt(d, id, buf, NULL, 0); @@ -
> 373,10 +384,11 @@ handle_work_for_shutdown_test(void *arg)
> 
>  		total += num;
>  	}
> -	worker_stats[id].handled_packets += num;
>  	count += num;
>  	returned = rte_distributor_return_pkt(d, id, buf, num);
> 
> +	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
> +			__ATOMIC_ACQ_REL);
>  	if (id == zero_id) {
>  		/* for worker zero, allow it to restart to pick up last packet
>  		 * when all workers are shutting down.
> @@ -387,7 +399,8 @@ 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_ACQ_REL);
>  			count += num;
>  			rte_pktmbuf_free(pkt);
>  			num = rte_distributor_get_pkt(d, id, buf, NULL, 0);
> @@ -454,7 +467,8 @@ 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_ACQUIRE));
> 
>  	if (total_packet_count() != BURST * 2) {
>  		printf("Line %d: Error, not all packets flushed. "
> @@ -507,7 +521,8 @@ 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_ACQUIRE));
> 
>  	if (total_packet_count() != BURST) {
>  		printf("Line %d: Error, not all packets flushed. "
> --
> 2.17.1
Lukasz Wojciechowski Oct. 17, 2020, 3:23 a.m. UTC | #2 
Hi Honnappa,

W dniu 16.10.2020 o 07:13, Honnappa Nagarahalli pisze:
> Hi Lukasz,
> 	I see that in commit 8/16, the same code is changed again (updating the counters using the RELAXED memory order). It is better to pull the statistics changes from 8/16 into this commit.

I reordered patches: "synchronize lcores statistics" and "fix freeing 
mbufs" to avoid changing same code.

Many thanks for the review

Lukasz

>
> Thanks,
> Honnappa
>
>> -----Original Message-----
>> From: dev <dev-bounces@dpdk.org> On Behalf Of Lukasz Wojciechowski
>> Sent: Saturday, October 10, 2020 11:05 AM
>> To: David Hunt <david.hunt@intel.com>; Bruce Richardson
>> <bruce.richardson@intel.com>
>> Cc: dev@dpdk.org; l.wojciechow@partner.samsung.com; stable@dpdk.org
>> Subject: [dpdk-dev] [PATCH v7 06/16] test/distributor: synchronize lcores
>> statistics
>>
>> 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 acquire/release mechanisms to synchronize.
>>
>> Fixes: c3eabff124e6 ("distributor: add unit tests")
>> Cc: bruce.richardson@intel.com
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
>> Acked-by: David Hunt <david.hunt@intel.com>
>> ---
>>   app/test/test_distributor.c | 43 +++++++++++++++++++++++++------------
>>   1 file changed, 29 insertions(+), 14 deletions(-)
>>
>> diff --git a/app/test/test_distributor.c b/app/test/test_distributor.c index
>> 6cd7a2edd..838459392 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_ACQUIRE);
> For ex: this line is changed in commit 8/16 as well. It is better to pull the changes from 8/16 to this commit.
>
>>   	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_RELEASE);
>>   }
>>
>>   /* this is the basic worker function for sanity test @@ -69,13 +73,13 @@
>> handle_work(void *arg)
>>   	num = rte_distributor_get_pkt(db, id, buf, NULL, 0);
>>   	while (!quit) {
>>   		__atomic_fetch_add(&worker_stats[id].handled_packets,
>> num,
>> -				__ATOMIC_RELAXED);
>> +				__ATOMIC_ACQ_REL);
>>   		count += num;
>>   		num = rte_distributor_get_pkt(db, id,
>>   				buf, buf, num);
>>   	}
>>   	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
>> -			__ATOMIC_RELAXED);
>> +			__ATOMIC_ACQ_REL);
>>   	count += num;
>>   	rte_distributor_return_pkt(db, id, buf, num);
>>   	return 0;
>> @@ -131,7 +135,8 @@ 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_ACQUIRE));
>>   	printf("Sanity test with all zero hashes done.\n");
>>
>>   	/* pick two flows and check they go correctly */ @@ -156,7 +161,9
>> @@ 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_ACQUIRE));
>>   		printf("Sanity test with two hash values done\n");
>>   	}
>>
>> @@ -182,7 +189,8 @@ 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_ACQUIRE));
>>   	printf("Sanity test with non-zero hashes done\n");
>>
>>   	rte_mempool_put_bulk(p, (void *)bufs, BURST); @@ -275,14
>> +283,16 @@ 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;
>>   		count += num;
>> +		__atomic_fetch_add(&worker_stats[id].handled_packets,
>> num,
>> +				__ATOMIC_ACQ_REL);
>>   		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;
>>   	count += num;
>> +	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
>> +			__ATOMIC_ACQ_REL);
>>   	rte_distributor_return_pkt(d, id, buf, num);
>>   	return 0;
>>   }
>> @@ -358,8 +368,9 @@ 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;
>>   		count += num;
>> +		__atomic_fetch_add(&worker_stats[id].handled_packets,
>> num,
>> +				__ATOMIC_ACQ_REL);
>>   		for (i = 0; i < num; i++)
>>   			rte_pktmbuf_free(buf[i]);
>>   		num = rte_distributor_get_pkt(d, id, buf, NULL, 0); @@ -
>> 373,10 +384,11 @@ handle_work_for_shutdown_test(void *arg)
>>
>>   		total += num;
>>   	}
>> -	worker_stats[id].handled_packets += num;
>>   	count += num;
>>   	returned = rte_distributor_return_pkt(d, id, buf, num);
>>
>> +	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
>> +			__ATOMIC_ACQ_REL);
>>   	if (id == zero_id) {
>>   		/* for worker zero, allow it to restart to pick up last packet
>>   		 * when all workers are shutting down.
>> @@ -387,7 +399,8 @@ 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_ACQ_REL);
>>   			count += num;
>>   			rte_pktmbuf_free(pkt);
>>   			num = rte_distributor_get_pkt(d, id, buf, NULL, 0);
>> @@ -454,7 +467,8 @@ 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_ACQUIRE));
>>
>>   	if (total_packet_count() != BURST * 2) {
>>   		printf("Line %d: Error, not all packets flushed. "
>> @@ -507,7 +521,8 @@ 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_ACQUIRE));
>>
>>   	if (total_packet_count() != BURST) {
>>   		printf("Line %d: Error, not all packets flushed. "
>> --
>> 2.17.1
diff mbox series

Patch

diff --git a/app/test/test_distributor.c b/app/test/test_distributor.c
index 6cd7a2edd..838459392 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_ACQUIRE);
 	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_RELEASE);
 }
 
 /* this is the basic worker function for sanity test
@@ -69,13 +73,13 @@  handle_work(void *arg)
 	num = rte_distributor_get_pkt(db, id, buf, NULL, 0);
 	while (!quit) {
 		__atomic_fetch_add(&worker_stats[id].handled_packets, num,
-				__ATOMIC_RELAXED);
+				__ATOMIC_ACQ_REL);
 		count += num;
 		num = rte_distributor_get_pkt(db, id,
 				buf, buf, num);
 	}
 	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
-			__ATOMIC_RELAXED);
+			__ATOMIC_ACQ_REL);
 	count += num;
 	rte_distributor_return_pkt(db, id, buf, num);
 	return 0;
@@ -131,7 +135,8 @@  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_ACQUIRE));
 	printf("Sanity test with all zero hashes done.\n");
 
 	/* pick two flows and check they go correctly */
@@ -156,7 +161,9 @@  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_ACQUIRE));
 		printf("Sanity test with two hash values done\n");
 	}
 
@@ -182,7 +189,8 @@  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_ACQUIRE));
 	printf("Sanity test with non-zero hashes done\n");
 
 	rte_mempool_put_bulk(p, (void *)bufs, BURST);
@@ -275,14 +283,16 @@  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;
 		count += num;
+		__atomic_fetch_add(&worker_stats[id].handled_packets, num,
+				__ATOMIC_ACQ_REL);
 		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;
 	count += num;
+	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
+			__ATOMIC_ACQ_REL);
 	rte_distributor_return_pkt(d, id, buf, num);
 	return 0;
 }
@@ -358,8 +368,9 @@  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;
 		count += num;
+		__atomic_fetch_add(&worker_stats[id].handled_packets, num,
+				__ATOMIC_ACQ_REL);
 		for (i = 0; i < num; i++)
 			rte_pktmbuf_free(buf[i]);
 		num = rte_distributor_get_pkt(d, id, buf, NULL, 0);
@@ -373,10 +384,11 @@  handle_work_for_shutdown_test(void *arg)
 
 		total += num;
 	}
-	worker_stats[id].handled_packets += num;
 	count += num;
 	returned = rte_distributor_return_pkt(d, id, buf, num);
 
+	__atomic_fetch_add(&worker_stats[id].handled_packets, num,
+			__ATOMIC_ACQ_REL);
 	if (id == zero_id) {
 		/* for worker zero, allow it to restart to pick up last packet
 		 * when all workers are shutting down.
@@ -387,7 +399,8 @@  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_ACQ_REL);
 			count += num;
 			rte_pktmbuf_free(pkt);
 			num = rte_distributor_get_pkt(d, id, buf, NULL, 0);
@@ -454,7 +467,8 @@  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_ACQUIRE));
 
 	if (total_packet_count() != BURST * 2) {
 		printf("Line %d: Error, not all packets flushed. "
@@ -507,7 +521,8 @@  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_ACQUIRE));
 
 	if (total_packet_count() != BURST) {
 		printf("Line %d: Error, not all packets flushed. "