``argc`` and ``argv`` arguments are provided to the ``rte_eal_init()``
function. The value returned is the number of parsed arguments:
-.. code-block:: c
-
- int ret = rte_eal_init(argc, argv);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Initializion the Environment Abstraction Layer (EAL). 8<
+ :end-before: >8 End of initializion the Environment Abstraction Layer (EAL).
+ :dedent: 1
The ``main()`` also allocates a mempool to hold the mbufs (Message Buffers)
used by the application:
-.. code-block:: c
-
- mbuf_pool = rte_mempool_create("MBUF_POOL",
- NUM_MBUFS * nb_ports,
- MBUF_SIZE,
- MBUF_CACHE_SIZE,
- sizeof(struct rte_pktmbuf_pool_private),
- rte_pktmbuf_pool_init, NULL,
- rte_pktmbuf_init, NULL,
- rte_socket_id(),
- 0);
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Allocates mempool to hold the mbufs. 8<
+ :end-before: >8 End of allocating mempool to hold mbuf.
+ :dedent: 1
Mbufs are the packet buffer structure used by DPDK. They are explained in
detail in the "Mbuf Library" section of the *DPDK Programmer's Guide*.
The ``main()`` function also initializes all the ports using the user defined
``port_init()`` function which is explained in the next section:
-.. code-block:: c
-
- RTE_ETH_FOREACH_DEV(portid) {
- if (port_init(portid, mbuf_pool) != 0) {
- rte_exit(EXIT_FAILURE,
- "Cannot init port %" PRIu8 "\n", portid);
- }
- }
-
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Initializing all ports. 8<
+ :end-before: >8 End of initializing all ports.
+ :dedent: 1
Once the initialization is complete, the application is ready to launch a
function on an lcore. In this example ``lcore_main()`` is called on a single
lcore.
-.. code-block:: c
-
- lcore_main();
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Called on single lcore. 8<
+ :end-before: >8 End of called on single lcore.
+ :dedent: 1
The ``lcore_main()`` function is explained below.
The main functional part of the port initialization used in the Basic
Forwarding application is shown below:
-.. code-block:: c
-
- static inline int
- port_init(uint16_t port, struct rte_mempool *mbuf_pool)
- {
- struct rte_eth_conf port_conf = port_conf_default;
- const uint16_t rx_rings = 1, tx_rings = 1;
- struct rte_ether_addr addr;
- int retval;
- uint16_t q;
-
- if (!rte_eth_dev_is_valid_port(port))
- return -1;
-
- /* Configure the Ethernet device. */
- retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
- if (retval != 0)
- return retval;
-
- /* Allocate and set up 1 RX queue per Ethernet port. */
- for (q = 0; q < rx_rings; q++) {
- retval = rte_eth_rx_queue_setup(port, q, RX_RING_SIZE,
- rte_eth_dev_socket_id(port), NULL, mbuf_pool);
- if (retval < 0)
- return retval;
- }
-
- /* Allocate and set up 1 TX queue per Ethernet port. */
- for (q = 0; q < tx_rings; q++) {
- retval = rte_eth_tx_queue_setup(port, q, TX_RING_SIZE,
- rte_eth_dev_socket_id(port), NULL);
- if (retval < 0)
- return retval;
- }
-
- /* Start the Ethernet port. */
- retval = rte_eth_dev_start(port);
- if (retval < 0)
- return retval;
-
- /* Enable RX in promiscuous mode for the Ethernet device. */
- retval = rte_eth_promiscuous_enable(port);
- if (retval != 0)
- return retval;
-
- return 0;
- }
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Main functional part of port initialization. 8<
+ :end-before: >8 End of main functional part of port initialization.
The Ethernet ports are configured with default settings using the
``rte_eth_dev_configure()`` function and the ``port_conf_default`` struct:
-.. code-block:: c
-
- static const struct rte_eth_conf port_conf_default = {
- .rxmode = { .max_rx_pkt_len = RTE_ETHER_MAX_LEN }
- };
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Configuration of ethernet ports. 8<
+ :end-before: >8 End of configuration of ethernet ports.
For this example the ports are set up with 1 RX and 1 TX queue using the
``rte_eth_rx_queue_setup()`` and ``rte_eth_tx_queue_setup()`` functions.
The Ethernet port is then started:
-.. code-block:: c
-
- retval = rte_eth_dev_start(port);
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Starting Ethernet port. 8<
+ :end-before: >8 End of starting of ethernet port.
+ :dedent: 1
Finally the RX port is set in promiscuous mode:
-.. code-block:: c
-
- retval = rte_eth_promiscuous_enable(port);
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Enable RX in promiscuous mode for the Ethernet device.
+ :end-before: End of setting RX port in promiscuous mode.
+ :dedent: 1
The Lcores Main
available lcores. For the Basic Forwarding application the lcore function
looks like the following:
-.. code-block:: c
-
- static __rte_noreturn void
- lcore_main(void)
- {
- uint16_t port;
-
- /*
- * Check that the port is on the same NUMA node as the polling thread
- * for best performance.
- */
- RTE_ETH_FOREACH_DEV(port)
- if (rte_eth_dev_socket_id(port) > 0 &&
- rte_eth_dev_socket_id(port) !=
- (int)rte_socket_id())
- printf("WARNING, port %u is on remote NUMA node to "
- "polling thread.\n\tPerformance will "
- "not be optimal.\n", port);
-
- printf("\nCore %u forwarding packets. [Ctrl+C to quit]\n",
- rte_lcore_id());
-
- /* Run until the application is quit or killed. */
- for (;;) {
- /*
- * Receive packets on a port and forward them on the paired
- * port. The mapping is 0 -> 1, 1 -> 0, 2 -> 3, 3 -> 2, etc.
- */
- RTE_ETH_FOREACH_DEV(port) {
-
- /* Get burst of RX packets, from first port of pair. */
- struct rte_mbuf *bufs[BURST_SIZE];
- const uint16_t nb_rx = rte_eth_rx_burst(port, 0,
- bufs, BURST_SIZE);
-
- if (unlikely(nb_rx == 0))
- continue;
-
- /* Send burst of TX packets, to second port of pair. */
- const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0,
- bufs, nb_rx);
-
- /* Free any unsent packets. */
- if (unlikely(nb_tx < nb_rx)) {
- uint16_t buf;
- for (buf = nb_tx; buf < nb_rx; buf++)
- rte_pktmbuf_free(bufs[buf]);
- }
- }
- }
- }
-
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Basic forwarding application lcore. 8<
+ :end-before: >8 End Basic forwarding application lcore.
The main work of the application is done within the loop:
-.. code-block:: c
-
- for (;;) {
- RTE_ETH_FOREACH_DEV(port) {
-
- /* Get burst of RX packets, from first port of pair. */
- struct rte_mbuf *bufs[BURST_SIZE];
- const uint16_t nb_rx = rte_eth_rx_burst(port, 0,
- bufs, BURST_SIZE);
-
- if (unlikely(nb_rx == 0))
- continue;
-
- /* Send burst of TX packets, to second port of pair. */
- const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0,
- bufs, nb_rx);
-
- /* Free any unsent packets. */
- if (unlikely(nb_tx < nb_rx)) {
- uint16_t buf;
- for (buf = nb_tx; buf < nb_rx; buf++)
- rte_pktmbuf_free(bufs[buf]);
- }
- }
- }
+.. literalinclude:: ../../../examples/skeleton/basicfwd.c
+ :language: c
+ :start-after: Main work of application loop. 8<
+ :end-before: >8 End of loop.
+ :dedent: 1
Packets are received in bursts on the RX ports and transmitted in bursts on
the TX ports. The ports are grouped in pairs with a simple mapping scheme
git.droids-corp.org / dpdk.git / blobdiff