-.. BSD LICENSE
- Copyright(c) 2010-2015 Intel Corporation. All rights reserved.
- All rights reserved.
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions
- are met:
-
- * Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- * Redistributions in binary form must reproduce the above copyright
- notice, this list of conditions and the following disclaimer in
- the documentation and/or other materials provided with the
- distribution.
- * Neither the name of Intel Corporation nor the names of its
- contributors may be used to endorse or promote products derived
- from this software without specific prior written permission.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.. SPDX-License-Identifier: BSD-3-Clause
+ Copyright(c) 2010-2015 Intel Corporation.
L2 Forwarding Sample Application (in Real and Virtualized Environments) with core load statistics.
==================================================================================================
* The destination MAC address is replaced by 02:00:00:00:00:TX_PORT_ID
-This application can be used to benchmark performance using a traffic-generator, as shown in the Figure 3.
+This application can be used to benchmark performance using a traffic-generator, as shown in the :numref:`figure_l2_fwd_benchmark_setup_jobstats`.
-The application can also be used in a virtualized environment as shown in Figure 4.
+The application can also be used in a virtualized environment as shown in :numref:`figure_l2_fwd_virtenv_benchmark_setup_jobstats`.
The L2 Forwarding application can also be used as a starting point for developing a new application based on the DPDK.
-.. _figure_3:
+.. _figure_l2_fwd_benchmark_setup_jobstats:
-**Figure 3. Performance Benchmark Setup (Basic Environment)**
+.. figure:: img/l2_fwd_benchmark_setup.*
-.. image4_png has been replaced
+ Performance Benchmark Setup (Basic Environment)
-|l2_fwd_benchmark_setup|
+.. _figure_l2_fwd_virtenv_benchmark_setup_jobstats:
-.. _figure_4:
+.. figure:: img/l2_fwd_virtenv_benchmark_setup.*
-**Figure 4. Performance Benchmark Setup (Virtualized Environment)**
+ Performance Benchmark Setup (Virtualized Environment)
-.. image5_png has been renamed
-
-|l2_fwd_virtenv_benchmark_setup|
Virtual Function Setup Instructions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Compiling the Application
-------------------------
-#. Go to the example directory:
-
- .. code-block:: console
-
- export RTE_SDK=/path/to/rte_sdk cd ${RTE_SDK}/examples/l2fwd-jobstats
-
-#. Set the target (a default target is used if not specified). For example:
-
- .. code-block:: console
-
- export RTE_TARGET=x86_64-native-linuxapp-gcc
+To compile the sample application see :doc:`compiling`.
- *See the DPDK Getting Started Guide* for possible RTE_TARGET values.
-
-#. Build the application:
-
- .. code-block:: console
-
- make
+The application is located in the ``l2fwd-jobstats`` sub-directory.
Running the Application
-----------------------
.. code-block:: console
- ./build/l2fwd-jobstats [EAL options] -- -p PORTMASK [-q NQ] [-l]
+ ./<build_dir>/examples/dpdk-l2fwd-jobstats [EAL options] -- -p PORTMASK [-q NQ] [-l]
where,
* l: Use locale thousands separator when formatting big numbers.
-To run the application in linuxapp environment with 4 lcores, 16 ports, 8 RX queues per lcore and
+To run the application in linux environment with 4 lcores, 16 ports, 8 RX queues per lcore and
thousands separator printing, issue the command:
.. code-block:: console
- $ ./build/l2fwd-jobstats -c f -n 4 -- -q 8 -p ffff -l
+ $ ./<build_dir>/examples/dpdk-l2fwd-jobstats -l 0-3 -n 4 -- -q 8 -p ffff -l
Refer to the *DPDK Getting Started Guide* for general information on running applications
and the Environment Abstraction Layer (EAL) options.
~~~~~~~~~~~~~~~~~~~~~~
The L2 Forwarding sample application takes specific parameters,
-in addition to Environment Abstraction Layer (EAL) arguments (see Section 9.3).
+in addition to Environment Abstraction Layer (EAL) arguments
+(see `Running the Application`_).
The preferred way to parse parameters is to use the getopt() function,
since it is part of a well-defined and portable library.
EAL arguments are parsed first, then application-specific arguments.
This is done at the beginning of the main() function:
-.. code-block:: c
-
- /* init EAL */
-
- ret = rte_eal_init(argc, argv);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Invalid EAL arguments\n");
-
- argc -= ret;
- argv += ret;
-
- /* parse application arguments (after the EAL ones) */
-
- ret = l2fwd_parse_args(argc, argv);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Invalid L2FWD arguments\n");
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Init EAL. 8<
+ :end-before: >8 End of init EAL.
+ :dedent: 1
Mbuf Pool Initialization
~~~~~~~~~~~~~~~~~~~~~~~~
The mbuf pool contains a set of mbuf objects that will be used by the driver
and the application to store network packet data:
-.. code-block:: c
-
- /* create the mbuf pool */
- l2fwd_pktmbuf_pool =
- rte_mempool_create("mbuf_pool", NB_MBUF,
- MBUF_SIZE, 32,
- sizeof(struct rte_pktmbuf_pool_private),
- rte_pktmbuf_pool_init, NULL,
- rte_pktmbuf_init, NULL,
- rte_socket_id(), 0);
-
- if (l2fwd_pktmbuf_pool == NULL)
- rte_exit(EXIT_FAILURE, "Cannot init mbuf pool\n");
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Create the mbuf pool. 8<
+ :end-before: >8 End of creation of mbuf pool.
+ :dedent: 1
The rte_mempool is a generic structure used to handle pools of objects.
-In this case, it is necessary to create a pool that will be used by the driver,
-which expects to have some reserved space in the mempool structure,
-sizeof(struct rte_pktmbuf_pool_private) bytes.
-The number of allocated pkt mbufs is NB_MBUF, with a size of MBUF_SIZE each.
-A per-lcore cache of 32 mbufs is kept.
+In this case, it is necessary to create a pool that will be used by the driver.
+The number of allocated pkt mbufs is NB_MBUF, with a data room size of
+RTE_MBUF_DEFAULT_BUF_SIZE each.
+A per-lcore cache of MEMPOOL_CACHE_SIZE mbufs is kept.
The memory is allocated in rte_socket_id() socket,
but it is possible to extend this code to allocate one mbuf pool per socket.
-Two callback pointers are also given to the rte_mempool_create() function:
-
-* The first callback pointer is to rte_pktmbuf_pool_init() and is used
- to initialize the private data of the mempool, which is needed by the driver.
- This function is provided by the mbuf API, but can be copied and extended by the developer.
-
-* The second callback pointer given to rte_mempool_create() is the mbuf initializer.
- The default is used, that is, rte_pktmbuf_init(), which is provided in the rte_mbuf library.
- If a more complex application wants to extend the rte_pktmbuf structure for its own needs,
- a new function derived from rte_pktmbuf_init( ) can be created.
+The rte_pktmbuf_pool_create() function uses the default mbuf pool and mbuf
+initializers, respectively rte_pktmbuf_pool_init() and rte_pktmbuf_init().
+An advanced application may want to use the mempool API to create the
+mbuf pool with more control.
Driver Initialization
~~~~~~~~~~~~~~~~~~~~~
To fully understand this code, it is recommended to study the chapters that related to the Poll Mode Driver
in the *DPDK Programmer's Guide* and the *DPDK API Reference*.
-.. code-block:: c
-
- nb_ports = rte_eth_dev_count();
-
- if (nb_ports == 0)
- rte_exit(EXIT_FAILURE, "No Ethernet ports - bye\n");
-
- if (nb_ports > RTE_MAX_ETHPORTS)
- nb_ports = RTE_MAX_ETHPORTS;
-
- /* reset l2fwd_dst_ports */
-
- for (portid = 0; portid < RTE_MAX_ETHPORTS; portid++)
- l2fwd_dst_ports[portid] = 0;
-
- last_port = 0;
-
- /*
- * Each logical core is assigned a dedicated TX queue on each port.
- */
- for (portid = 0; portid < nb_ports; portid++) {
- /* skip ports that are not enabled */
- if ((l2fwd_enabled_port_mask & (1 << portid)) == 0)
- continue;
-
- if (nb_ports_in_mask % 2) {
- l2fwd_dst_ports[portid] = last_port;
- l2fwd_dst_ports[last_port] = portid;
- }
- else
- last_port = portid;
-
- nb_ports_in_mask++;
-
- rte_eth_dev_info_get((uint8_t) portid, &dev_info);
- }
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Reset l2fwd_dst_ports. 8<
+ :end-before: >8 End of reset l2fwd_dst_ports.
+ :dedent: 1
The next step is to configure the RX and TX queues.
For each port, there is only one RX queue (only one lcore is able to poll a given port).
The number of TX queues depends on the number of available lcores.
The rte_eth_dev_configure() function is used to configure the number of queues for a port:
-.. code-block:: c
-
- ret = rte_eth_dev_configure((uint8_t)portid, 1, 1, &port_conf);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Cannot configure device: "
- "err=%d, port=%u\n",
- ret, portid);
-
-The global configuration is stored in a static structure:
-
-.. code-block:: c
-
- static const struct rte_eth_conf port_conf = {
- .rxmode = {
- .split_hdr_size = 0,
- .header_split = 0, /**< Header Split disabled */
- .hw_ip_checksum = 0, /**< IP checksum offload disabled */
- .hw_vlan_filter = 0, /**< VLAN filtering disabled */
- .jumbo_frame = 0, /**< Jumbo Frame Support disabled */
- .hw_strip_crc= 0, /**< CRC stripped by hardware */
- },
-
- .txmode = {
- .mq_mode = ETH_DCB_NONE
- },
- };
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Configure the RX and TX queues. 8<
+ :end-before: >8 End of configuring the RX and TX queues.
+ :dedent: 2
RX Queue Initialization
~~~~~~~~~~~~~~~~~~~~~~~
If there are 16 ports on the target (and if the portmask argument is -p ffff ),
the application will need four lcores to poll all the ports.
-.. code-block:: c
-
- ret = rte_eth_rx_queue_setup(portid, 0, nb_rxd,
- rte_eth_dev_socket_id(portid),
- NULL,
- l2fwd_pktmbuf_pool);
-
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "rte_eth_rx_queue_setup:err=%d, port=%u\n",
- ret, (unsigned) portid);
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: RX queue initialization. 8<
+ :end-before: >8 End of RX queue initialization.
+ :dedent: 2
The list of queues that must be polled for a given lcore is stored in a private structure called struct lcore_queue_conf.
-.. code-block:: c
-
- struct lcore_queue_conf {
- unsigned n_rx_port;
- unsigned rx_port_list[MAX_RX_QUEUE_PER_LCORE];
- truct mbuf_table tx_mbufs[RTE_MAX_ETHPORTS];
-
- struct rte_timer rx_timers[MAX_RX_QUEUE_PER_LCORE];
- struct rte_jobstats port_fwd_jobs[MAX_RX_QUEUE_PER_LCORE];
-
- struct rte_timer flush_timer;
- struct rte_jobstats flush_job;
- struct rte_jobstats idle_job;
- struct rte_jobstats_context jobs_context;
-
- rte_atomic16_t stats_read_pending;
- rte_spinlock_t lock;
- } __rte_cache_aligned;
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: List of queues to be polled for given lcore. 8<
+ :end-before: >8 End of list of queues to be polled for given lcore.
Values of struct lcore_queue_conf:
* n_rx_port and rx_port_list[] are used in the main packet processing loop
- (see Section 9.4.6 "Receive, Process and Transmit Packets" later in this chapter).
+ (see Section `Receive, Process and Transmit Packets`_ later in this chapter).
* rx_timers and flush_timer are used to ensure forced TX on low packet rate.
Each lcore should be able to transmit on any port. For every port, a single TX queue is initialized.
-.. code-block:: c
-
- /* init one TX queue on each port */
-
- fflush(stdout);
- ret = rte_eth_tx_queue_setup(portid, 0, nb_txd,
- rte_eth_dev_socket_id(portid),
- NULL);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "rte_eth_tx_queue_setup:err=%d, port=%u\n",
- ret, (unsigned) portid);
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Init one TX queue on each port. 8<
+ :end-before: >8 End of init one TX queue on each port.
+ :dedent: 2
Jobs statistics initialization
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Flush job statistics
-.. code-block:: c
-
- rte_jobstats_init(&qconf->flush_job, "flush", drain_tsc, drain_tsc,
- drain_tsc, 0);
-
- rte_timer_init(&qconf->flush_timer);
- ret = rte_timer_reset(&qconf->flush_timer, drain_tsc, PERIODICAL,
- lcore_id, &l2fwd_flush_job, NULL);
-
- if (ret < 0) {
- rte_exit(1, "Failed to reset flush job timer for lcore %u: %s",
- lcore_id, rte_strerror(-ret));
- }
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Add flush job. 8<
+ :end-before: >8 End of add flush job.
+ :dedent: 2
* Statistics per RX port
-.. code-block:: c
-
- rte_jobstats_init(job, name, 0, drain_tsc, 0, MAX_PKT_BURST);
- rte_jobstats_set_update_period_function(job, l2fwd_job_update_cb);
-
- rte_timer_init(&qconf->rx_timers[i]);
- ret = rte_timer_reset(&qconf->rx_timers[i], 0, PERIODICAL, lcore_id,
- l2fwd_fwd_job, (void *)(uintptr_t)i);
-
- if (ret < 0) {
- rte_exit(1, "Failed to reset lcore %u port %u job timer: %s",
- lcore_id, qconf->rx_port_list[i], rte_strerror(-ret));
- }
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Setup forward job. 8<
+ :end-before: >8 End of forward job.
+ :dedent: 3
Following parameters are passed to rte_jobstats_init():
The forwarding path is reworked comparing to original L2 Forwarding application.
In the l2fwd_main_loop() function three loops are placed.
-.. code-block:: c
-
- for (;;) {
- rte_spinlock_lock(&qconf->lock);
-
- do {
- rte_jobstats_context_start(&qconf->jobs_context);
-
- /* Do the Idle job:
- * - Read stats_read_pending flag
- * - check if some real job need to be executed
- */
- rte_jobstats_start(&qconf->jobs_context, &qconf->idle_job);
-
- do {
- uint8_t i;
- uint64_t now = rte_get_timer_cycles();
-
- need_manage = qconf->flush_timer.expire < now;
- /* Check if we was esked to give a stats. */
- stats_read_pending =
- rte_atomic16_read(&qconf->stats_read_pending);
- need_manage |= stats_read_pending;
-
- for (i = 0; i < qconf->n_rx_port && !need_manage; i++)
- need_manage = qconf->rx_timers[i].expire < now;
-
- } while (!need_manage);
- rte_jobstats_finish(&qconf->idle_job, qconf->idle_job.target);
-
- rte_timer_manage();
- rte_jobstats_context_finish(&qconf->jobs_context);
- } while (likely(stats_read_pending == 0));
-
- rte_spinlock_unlock(&qconf->lock);
- rte_pause();
- }
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Minimize impact of stats reading. 8<
+ :end-before: >8 End of minimize impact of stats reading.
+ :dedent: 1
First infinite for loop is to minimize impact of stats reading. Lock is only locked/unlocked when asked.
The main task of l2fwd_fwd_job() function is to read ingress packets from the RX queue of particular port and forward it.
This is done using the following code:
-.. code-block:: c
-
- total_nb_rx = rte_eth_rx_burst((uint8_t) portid, 0, pkts_burst,
- MAX_PKT_BURST);
-
- for (j = 0; j < total_nb_rx; j++) {
- m = pkts_burst[j];
- rte_prefetch0(rte_pktmbuf_mtod(m, void *));
- l2fwd_simple_forward(m, portid);
- }
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Call rx burst 2 times. 8<
+ :end-before: >8 End of call rx burst 2 times.
+ :dedent: 1
Packets are read in a burst of size MAX_PKT_BURST.
Then, each mbuf in the table is processed by the l2fwd_simple_forward() function.
After first read second try is issued.
-.. code-block:: c
-
- if (total_nb_rx == MAX_PKT_BURST) {
- const uint16_t nb_rx = rte_eth_rx_burst((uint8_t) portid, 0, pkts_burst,
- MAX_PKT_BURST);
-
- total_nb_rx += nb_rx;
- for (j = 0; j < nb_rx; j++) {
- m = pkts_burst[j];
- rte_prefetch0(rte_pktmbuf_mtod(m, void *));
- l2fwd_simple_forward(m, portid);
- }
- }
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Read second try. 8<
+ :end-before: >8 End of read second try.
+ :dedent: 1
This second read is important to give job stats library a feedback how many packets was processed.
-.. code-block:: c
-
- /* Adjust period time in which we are running here. */
- if (rte_jobstats_finish(job, total_nb_rx) != 0) {
- rte_timer_reset(&qconf->rx_timers[port_idx], job->period, PERIODICAL,
- lcore_id, l2fwd_fwd_job, arg);
- }
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Adjust period time in which we are running here. 8<
+ :end-before: >8 End of adjust period time in which we are running.
+ :dedent: 1
To maximize performance exactly MAX_PKT_BURST is expected (the target value) to be read for each l2fwd_fwd_job() call.
If total_nb_rx is smaller than target value job->period will be increased. If it is greater the period will be decreased.
a destination port is assigned that is either the next or previous enabled port from the portmask.
Naturally, the number of ports in the portmask must be even, otherwise, the application exits.
-.. code-block:: c
-
- static void
- l2fwd_simple_forward(struct rte_mbuf *m, unsigned portid)
- {
- struct ether_hdr *eth;
- void *tmp;
- unsigned dst_port;
-
- dst_port = l2fwd_dst_ports[portid];
-
- eth = rte_pktmbuf_mtod(m, struct ether_hdr *);
-
- /* 02:00:00:00:00:xx */
-
- tmp = ð->d_addr.addr_bytes[0];
-
- *((uint64_t *)tmp) = 0x000000000002 + ((uint64_t) dst_port << 40);
-
- /* src addr */
-
- ether_addr_copy(&l2fwd_ports_eth_addr[dst_port], ð->s_addr);
-
- l2fwd_send_packet(m, (uint8_t) dst_port);
- }
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Start of l2fwd_simple_forward. 8<
+ :end-before: >8 End of l2fwd_simple_forward.
Then, the packet is sent using the l2fwd_send_packet (m, dst_port) function.
For this test application, the processing is exactly the same for all packets arriving on the same RX port.
The l2fwd_send_packet() function stores the packet in a per-lcore and per-txport table.
If the table is full, the whole packets table is transmitted using the l2fwd_send_burst() function:
-.. code-block:: c
-
- /* Send the packet on an output interface */
-
- static int
- l2fwd_send_packet(struct rte_mbuf *m, uint8_t port)
- {
- unsigned lcore_id, len;
- struct lcore_queue_conf *qconf;
-
- lcore_id = rte_lcore_id();
- qconf = &lcore_queue_conf[lcore_id];
- len = qconf->tx_mbufs[port].len;
- qconf->tx_mbufs[port].m_table[len] = m;
- len++;
-
- /* enough pkts to be sent */
-
- if (unlikely(len == MAX_PKT_BURST)) {
- l2fwd_send_burst(qconf, MAX_PKT_BURST, port);
- len = 0;
- }
-
- qconf->tx_mbufs[port].len = len; return 0;
- }
+.. literalinclude:: ../../../examples/l2fwd-crypto/main.c
+ :language: c
+ :start-after: Enqueue packets for TX and prepare them to be sent. 8<
+ :end-before: >8 End of Enqueuing packets for TX.
To ensure that no packets remain in the tables, the flush job exists. The l2fwd_flush_job()
is called periodically to for each lcore draining TX queue of each port.
This technique introduces some latency when there are not many packets to send,
however it improves performance:
-.. code-block:: c
-
- static void
- l2fwd_flush_job(__rte_unused struct rte_timer *timer, __rte_unused void *arg)
- {
- uint64_t now;
- unsigned lcore_id;
- struct lcore_queue_conf *qconf;
- struct mbuf_table *m_table;
- uint8_t portid;
-
- lcore_id = rte_lcore_id();
- qconf = &lcore_queue_conf[lcore_id];
-
- rte_jobstats_start(&qconf->jobs_context, &qconf->flush_job);
-
- now = rte_get_timer_cycles();
- lcore_id = rte_lcore_id();
- qconf = &lcore_queue_conf[lcore_id];
- for (portid = 0; portid < RTE_MAX_ETHPORTS; portid++) {
- m_table = &qconf->tx_mbufs[portid];
- if (m_table->len == 0 || m_table->next_flush_time <= now)
- continue;
-
- l2fwd_send_burst(qconf, portid);
- }
-
-
- /* Pass target to indicate that this job is happy of time interval
- * in which it was called. */
- rte_jobstats_finish(&qconf->flush_job, qconf->flush_job.target);
- }
-
-.. |l2_fwd_benchmark_setup| image:: img/l2_fwd_benchmark_setup.*
-
-.. |l2_fwd_virtenv_benchmark_setup| image:: img/l2_fwd_virtenv_benchmark_setup.*
+.. literalinclude:: ../../../examples/l2fwd-jobstats/main.c
+ :language: c
+ :start-after: Draining TX queue of each port. 8<
+ :end-before: >8 End of draining TX queue of each port.
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