+ return PASS;
+}
+
+static struct rte_lpm *g_lpm;
+static struct rte_rcu_qsbr *g_v;
+static uint32_t g_ip = RTE_IPV4(192, 0, 2, 100);
+static volatile uint8_t writer_done;
+/* Report quiescent state interval every 1024 lookups. Larger critical
+ * sections in reader will result in writer polling multiple times.
+ */
+#define QSBR_REPORTING_INTERVAL 1024
+#define WRITER_ITERATIONS 512
+
+/*
+ * Reader thread using rte_lpm data structure with RCU.
+ */
+static int
+test_lpm_rcu_qsbr_reader(void *arg)
+{
+ int i;
+ uint32_t next_hop_return = 0;
+
+ RTE_SET_USED(arg);
+ /* Register this thread to report quiescent state */
+ rte_rcu_qsbr_thread_register(g_v, 0);
+ rte_rcu_qsbr_thread_online(g_v, 0);
+
+ do {
+ for (i = 0; i < QSBR_REPORTING_INTERVAL; i++)
+ rte_lpm_lookup(g_lpm, g_ip, &next_hop_return);
+
+ /* Update quiescent state */
+ rte_rcu_qsbr_quiescent(g_v, 0);
+ } while (!writer_done);
+
+ rte_rcu_qsbr_thread_offline(g_v, 0);
+ rte_rcu_qsbr_thread_unregister(g_v, 0);
+
+ return 0;
+}
+
+/*
+ * rte_lpm_rcu_qsbr_add sync mode functional test.
+ * 1 Reader and 1 writer. They cannot be in the same thread in this test.
+ * - Create LPM which supports 1 tbl8 group at max
+ * - Add RCU QSBR variable with sync mode to LPM
+ * - Register a reader thread. Reader keeps looking up a specific rule.
+ * - Writer keeps adding and deleting a specific rule with depth=28 (> 24)
+ */
+int32_t
+test21(void)
+{
+ struct rte_lpm_config config;
+ size_t sz;
+ int32_t status;
+ uint32_t i, next_hop;
+ uint8_t depth;
+ struct rte_lpm_rcu_config rcu_cfg = {0};
+
+ if (rte_lcore_count() < 2) {
+ printf("Not enough cores for %s, expecting at least 2\n",
+ __func__);
+ return TEST_SKIPPED;