test/distributor: fix 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 mechanisms to synchronize.
Relaxed memory model is used.

Fixes: c3eabff124e6 ("distributor: add unit tests")
Cc: stable@dpdk.org
Signed-off-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
Acked-by: David Hunt <david.hunt@intel.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>

diff --git a/app/test/test_distributor.c b/app/test/test_distributor.c
index ec1fe348baa37412d4489fdca512c45c8198d14d..4343efed14ed2244d5b819ea58e0b4fce5df8411 100644 (file)
--- 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. "