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

[Tomasz Duszynski]

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 <t...@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