[dpdk-dev] [PATCH 2/2] examples/kni: stop lcores while doing kni ops

[Tomasz Duszynski <tdu@semihalf.com>]

Since the transmit and receive functions should not be invoked when
the device is stopped, stop lcores during kni ops and restart them
after device is started once again.

Signed-off-by: Tomasz Duszynski <tdu@semihalf.com>
---
 examples/kni/main.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/examples/kni/main.c b/examples/kni/main.c
index cb48fb5..5c50448 100644
--- a/examples/kni/main.c
+++ b/examples/kni/main.c
@@ -166,6 +166,23 @@ static int kni_change_mtu(uint16_t port_id, unsigned int new_mtu);
 static int kni_config_network_interface(uint16_t port_id, uint8_t if_up);

 static rte_atomic32_t kni_stop = RTE_ATOMIC32_INIT(0);
+static rte_atomic32_t kni_restart = RTE_ATOMIC32_INIT(0);
+
+static void
+kni_stop_lcores(void)
+{
+	unsigned int i;
+
+	rte_atomic32_inc(&kni_restart);
+	rte_atomic32_inc(&kni_stop);
+
+	RTE_LCORE_FOREACH(i) {
+		if (i == rte_lcore_id())
+			continue;
+
+		rte_eal_wait_lcore(i);
+	}
+}

 /* Print out statistics on packets handled */
 static void
@@ -712,6 +729,7 @@ kni_change_mtu(uint16_t port_id, unsigned int new_mtu)

 	RTE_LOG(INFO, APP, "Change MTU of port %d to %u\n", port_id, new_mtu);

+	kni_stop_lcores();
 	/* Stop specific port */
 	rte_eth_dev_stop(port_id);

@@ -755,6 +773,8 @@ kni_config_network_interface(uint16_t port_id, uint8_t if_up)
 	RTE_LOG(INFO, APP, "Configure network interface of %d %s\n",
 					port_id, if_up ? "up" : "down");

+	kni_stop_lcores();
+
 	if (if_up != 0) { /* Configure network interface up */
 		rte_eth_dev_stop(port_id);
 		ret = rte_eth_dev_start(port_id);
@@ -911,6 +931,7 @@ main(int argc, char** argv)
 	}
 	check_all_ports_link_status(nb_sys_ports, ports_mask);

+restart:
 	/* Launch per-lcore function on every lcore */
 	rte_eal_mp_remote_launch(main_loop, NULL, CALL_MASTER);
 	RTE_LCORE_FOREACH_SLAVE(i) {
@@ -918,6 +939,13 @@ main(int argc, char** argv)
 			return -1;
 	}

+	if (rte_atomic32_read(&kni_restart)) {
+		rte_atomic32_dec(&kni_stop);
+		rte_atomic32_dec(&kni_restart);
+
+		goto restart;
+	}
+
 	/* Release resources */
 	for (port = 0; port < nb_sys_ports; port++) {
 		if (!(ports_mask & (1 << port)))
--
2.7.4