test/rcu: fix build with low core count

When RTE_MAX_LCORE value is small, following compiler errors
are observed.

../app/test/test_rcu_qsbr.c:296:54: error: iteration 2 invokes
undefined behavior [-Werror=aggressive-loop-optimizations]

../app/test/test_rcu_qsbr.c:315:55: error: array subscript is above
array bounds [-Werror=array-bounds]

Fixes: b87089b0bb19 ("test/rcu: add API and functional tests")
Cc: stable@dpdk.org
Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Tested-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
Reviewed-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>

diff --git a/app/test/test_rcu_qsbr.c b/app/test/test_rcu_qsbr.c
index 7ae66e4..ab37a06 100644 (file)
--- a/app/test/test_rcu_qsbr.c
+++ b/app/test/test_rcu_qsbr.c
@@ -286,13 +286,13 @@ static int
 test_rcu_qsbr_start(void)
 {
        uint64_t token;
-       int i;
+       unsigned int i;
 
        printf("\nTest rte_rcu_qsbr_start()\n");
 
        rte_rcu_qsbr_init(t[0], RTE_MAX_LCORE);
 
-       for (i = 0; i < 3; i++)
+       for (i = 0; i < num_cores; i++)
                rte_rcu_qsbr_thread_register(t[0], enabled_core_ids[i]);
 
        token = rte_rcu_qsbr_start(t[0]);
@@ -306,14 +306,18 @@ test_rcu_qsbr_check_reader(void *arg)
 {
        struct rte_rcu_qsbr *temp;
        uint8_t read_type = (uint8_t)((uintptr_t)arg);
+       unsigned int i;
 
        temp = t[read_type];
 
        /* Update quiescent state counter */
-       rte_rcu_qsbr_quiescent(temp, enabled_core_ids[0]);
-       rte_rcu_qsbr_quiescent(temp, enabled_core_ids[1]);
-       rte_rcu_qsbr_thread_unregister(temp, enabled_core_ids[2]);
-       rte_rcu_qsbr_quiescent(temp, enabled_core_ids[3]);
+       for (i = 0; i < num_cores; i++) {
+               if (i % 2 == 0)
+                       rte_rcu_qsbr_quiescent(temp, enabled_core_ids[i]);
+               else
+                       rte_rcu_qsbr_thread_unregister(temp,
+                                                       enabled_core_ids[i]);
+       }
        return 0;
 }
 
@@ -324,7 +328,8 @@ test_rcu_qsbr_check_reader(void *arg)
 static int
 test_rcu_qsbr_check(void)
 {
-       int i, ret;
+       int ret;
+       unsigned int i;
        uint64_t token;
 
        printf("\nTest rte_rcu_qsbr_check()\n");
@@ -342,7 +347,7 @@ test_rcu_qsbr_check(void)
        ret = rte_rcu_qsbr_check(t[0], token, true);
        TEST_RCU_QSBR_RETURN_IF_ERROR((ret == 0), "Blocking QSBR check");
 
-       for (i = 0; i < 3; i++)
+       for (i = 0; i < num_cores; i++)
                rte_rcu_qsbr_thread_register(t[0], enabled_core_ids[i]);
 
        ret = rte_rcu_qsbr_check(t[0], token, false);
@@ -357,7 +362,7 @@ test_rcu_qsbr_check(void)
        /* Threads are offline, hence this should pass */
        TEST_RCU_QSBR_RETURN_IF_ERROR((ret == 0), "Non-blocking QSBR check");
 
-       for (i = 0; i < 3; i++)
+       for (i = 0; i < num_cores; i++)
                rte_rcu_qsbr_thread_unregister(t[0], enabled_core_ids[i]);
 
        ret = rte_rcu_qsbr_check(t[0], token, true);
@@ -365,7 +370,7 @@ test_rcu_qsbr_check(void)
 
        rte_rcu_qsbr_init(t[0], RTE_MAX_LCORE);
 
-       for (i = 0; i < 4; i++)
+       for (i = 0; i < num_cores; i++)
                rte_rcu_qsbr_thread_register(t[0], enabled_core_ids[i]);
 
        token = rte_rcu_qsbr_start(t[0]);
@@ -928,7 +933,7 @@ end:
 static int
 test_rcu_qsbr_dump(void)
 {
-       int i;
+       unsigned int i;
 
        printf("\nTest rte_rcu_qsbr_dump()\n");
 
@@ -945,7 +950,7 @@ test_rcu_qsbr_dump(void)
 
        rte_rcu_qsbr_thread_register(t[0], enabled_core_ids[0]);
 
-       for (i = 1; i < 3; i++)
+       for (i = 1; i < num_cores; i++)
                rte_rcu_qsbr_thread_register(t[1], enabled_core_ids[i]);
 
        rte_rcu_qsbr_dump(stdout, t[0]);
@@ -1095,7 +1100,7 @@ test_rcu_qsbr_sw_sv_3qs(void)
 {
        uint64_t token[3];
        uint32_t c;
-       int i;
+       int i, num_readers;
        int32_t pos[3];
 
        writer_done = 0;
@@ -1118,7 +1123,11 @@ test_rcu_qsbr_sw_sv_3qs(void)
        thread_info[0].ih = 0;
 
        /* Reader threads are launched */
-       for (i = 0; i < 4; i++)
+       /* Keep the number of reader threads low to reduce
+        * the execution time.
+        */
+       num_readers = num_cores < 4 ? num_cores : 4;
+       for (i = 0; i < num_readers; i++)
                rte_eal_remote_launch(test_rcu_qsbr_reader, &thread_info[0],
                                        enabled_core_ids[i]);
 
@@ -1151,7 +1160,7 @@ test_rcu_qsbr_sw_sv_3qs(void)
 
        /* Check the quiescent state status */
        rte_rcu_qsbr_check(t[0], token[0], true);
-       for (i = 0; i < 4; i++) {
+       for (i = 0; i < num_readers; i++) {
                c = hash_data[0][0][enabled_core_ids[i]];
                if (c != COUNTER_VALUE && c != 0) {
                        printf("Reader lcore %d did not complete #0 = %d\n",
@@ -1169,7 +1178,7 @@ test_rcu_qsbr_sw_sv_3qs(void)
 
        /* Check the quiescent state status */
        rte_rcu_qsbr_check(t[0], token[1], true);
-       for (i = 0; i < 4; i++) {
+       for (i = 0; i < num_readers; i++) {
                c = hash_data[0][3][enabled_core_ids[i]];
                if (c != COUNTER_VALUE && c != 0) {
                        printf("Reader lcore %d did not complete #3 = %d\n",
@@ -1187,7 +1196,7 @@ test_rcu_qsbr_sw_sv_3qs(void)
 
        /* Check the quiescent state status */
        rte_rcu_qsbr_check(t[0], token[2], true);
-       for (i = 0; i < 4; i++) {
+       for (i = 0; i < num_readers; i++) {
                c = hash_data[0][6][enabled_core_ids[i]];
                if (c != COUNTER_VALUE && c != 0) {
                        printf("Reader lcore %d did not complete #6 = %d\n",
@@ -1206,7 +1215,7 @@ test_rcu_qsbr_sw_sv_3qs(void)
        writer_done = 1;
 
        /* Wait and check return value from reader threads */
-       for (i = 0; i < 4; i++)
+       for (i = 0; i < num_readers; i++)
                if (rte_eal_wait_lcore(enabled_core_ids[i]) < 0)
                        goto error;
        rte_hash_free(h[0]);
@@ -1236,6 +1245,12 @@ test_rcu_qsbr_mw_mv_mqs(void)
        unsigned int i, j;
        unsigned int test_cores;
 
+       if (RTE_MAX_LCORE < 5 || num_cores < 4) {
+               printf("Not enough cores for %s, expecting at least 5\n",
+                       __func__);
+               return TEST_SKIPPED;
+       }
+
        writer_done = 0;
        test_cores = num_cores / 4;
        test_cores = test_cores * 4;
@@ -1321,11 +1336,6 @@ test_rcu_qsbr_main(void)
 {
        uint16_t core_id;
 
-       if (rte_lcore_count() < 5) {
-               printf("Not enough cores for rcu_qsbr_autotest, expecting at least 5\n");
-               return TEST_SKIPPED;
-       }
-
        num_cores = 0;
        RTE_LCORE_FOREACH_WORKER(core_id) {
                enabled_core_ids[num_cores] = core_id;