[dpdk-dev] [PATCH RFC 3/3] examples: example showing use of callbacks.

[Bruce Richardson <bruce.richardson@intel.com>]

Rough example showing how callbacks can be used to insert a timestamp
into each packet on RX. Then on TX the timestamp is used to calculate
the packet latency in cycles through the app.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 examples/rxtx_callbacks/Makefile   |  57 ++++++++++
 examples/rxtx_callbacks/basicfwd.c | 222 +++++++++++++++++++++++++++++++++++++
 examples/rxtx_callbacks/basicfwd.h |  46 ++++++++
 3 files changed, 325 insertions(+)
 create mode 100644 examples/rxtx_callbacks/Makefile
 create mode 100644 examples/rxtx_callbacks/basicfwd.c
 create mode 100644 examples/rxtx_callbacks/basicfwd.h

diff --git a/examples/rxtx_callbacks/Makefile b/examples/rxtx_callbacks/Makefile
new file mode 100644
index 0000000..4a5d99f
--- /dev/null
+++ b/examples/rxtx_callbacks/Makefile
@@ -0,0 +1,57 @@
+#   BSD LICENSE
+#
+#   Copyright(c) 2010-2014 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.
+
+ifeq ($(RTE_SDK),)
+$(error "Please define RTE_SDK environment variable")
+endif
+
+# Default target, can be overridden by command line or environment
+RTE_TARGET ?= x86_64-native-linuxapp-gcc
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+# binary name
+APP = basicfwd
+
+# all source are stored in SRCS-y
+SRCS-y := basicfwd.c
+
+CFLAGS += $(WERROR_FLAGS)
+
+# workaround for a gcc bug with noreturn attribute
+# http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12603
+ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y)
+CFLAGS_main.o += -Wno-return-type
+endif
+
+EXTRA_CFLAGS += -O3 -g -Wfatal-errors
+
+include $(RTE_SDK)/mk/rte.extapp.mk
diff --git a/examples/rxtx_callbacks/basicfwd.c b/examples/rxtx_callbacks/basicfwd.c
new file mode 100644
index 0000000..0209bf4
--- /dev/null
+++ b/examples/rxtx_callbacks/basicfwd.c
@@ -0,0 +1,222 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 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.
+ */
+
+#include <stdint.h>
+#include <inttypes.h>
+#include <rte_eal.h>
+#include <rte_ethdev.h>
+#include <rte_cycles.h>
+#include <rte_lcore.h>
+#include <rte_mbuf.h>
+#include "basicfwd.h"
+
+#define RX_RING_SIZE 128
+#define TX_RING_SIZE 512
+
+#define NUM_MBUFS 8191
+#define MBUF_SIZE (1600 + sizeof(struct rte_mbuf) + RTE_PKTMBUF_HEADROOM)
+#define MBUF_CACHE_SIZE 250
+#define BURST_SIZE 32
+
+static const struct rte_eth_conf port_conf_default = {
+	.rxmode = { .max_rx_pkt_len = ETHER_MAX_LEN, },
+};
+
+static unsigned nb_ports;
+
+static struct {
+	uint64_t total_cycles;
+	uint64_t total_pkts;
+} latency_numbers;
+
+
+static uint16_t
+add_timestamps(uint8_t port __rte_unused, uint16_t qidx __rte_unused,
+		struct rte_mbuf **pkts, uint16_t nb_pkts, void *_ __rte_unused)
+{
+	unsigned i;
+	uint64_t now = rte_rdtsc();
+	for (i = 0; i < nb_pkts; i++)
+		pkts[i]->udata64 = now;
+	return nb_pkts;
+}
+
+static uint16_t
+calc_latency(uint8_t port __rte_unused, uint16_t qidx __rte_unused,
+		struct rte_mbuf **pkts, uint16_t nb_pkts, void *_ __rte_unused)
+{
+	uint64_t cycles = 0;
+	uint64_t now = rte_rdtsc();
+	unsigned i;
+	for (i = 0; i < nb_pkts; i++)
+		cycles += now - pkts[i]->udata64;
+	latency_numbers.total_cycles += cycles;
+	latency_numbers.total_pkts += nb_pkts;
+
+	if (latency_numbers.total_pkts > (100 * 1000 * 1000ULL)) {
+		printf("Latency = %"PRIu64" cycles\n",
+		latency_numbers.total_cycles / latency_numbers.total_pkts);
+		latency_numbers.total_cycles = latency_numbers.total_pkts = 0;
+	}
+	return nb_pkts;
+}
+
+/*
+ * Initialises a given port using global settings and with the rx buffers
+ * coming from the mbuf_pool passed as parameter
+ */
+static inline int
+port_init(uint8_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;
+	int retval;
+	uint16_t q;
+
+	if (port >= rte_eth_dev_count())
+		return -1;
+
+	retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
+	if (retval != 0)
+		return retval;
+
+	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;
+	}
+
+	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;
+	}
+
+	retval  = rte_eth_dev_start(port);
+	if (retval < 0)
+		return retval;
+
+	struct ether_addr addr;
+	rte_eth_macaddr_get(port, &addr);
+	printf("Port %u MAC: %02"PRIx8" %02"PRIx8" %02"PRIx8
+			" %02"PRIx8" %02"PRIx8" %02"PRIx8"\n",
+			(unsigned)port,
+			addr.addr_bytes[0], addr.addr_bytes[1],
+			addr.addr_bytes[2], addr.addr_bytes[3],
+			addr.addr_bytes[4], addr.addr_bytes[5]);
+
+	rte_eth_promiscuous_enable(port);
+	rte_eth_add_rx_callback(port, 0, add_timestamps, NULL);
+	rte_eth_add_tx_callback(port, 0, calc_latency, NULL);
+
+	return 0;
+}
+
+/*
+ * Main thread that does the work, reading from INPUT_PORT
+ * and writing to OUTPUT_PORT
+ */
+static  __attribute__((noreturn)) void
+lcore_main(void)
+{
+	uint8_t port;
+	for (port = 0; port < nb_ports; 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());
+	for (;;) {
+		for (port = 0; port < nb_ports; port++) {
+			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;
+			const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0,
+					bufs, nb_rx);
+			if (unlikely(nb_tx < nb_rx)) {
+				uint16_t buf;
+				for (buf = nb_tx; buf < nb_rx; buf++)
+					rte_pktmbuf_free(bufs[buf]);
+			}
+		}
+	}
+}
+
+/* Main function, does initialisation and calls the per-lcore functions */
+int
+MAIN(int argc, char *argv[])
+{
+	struct rte_mempool *mbuf_pool;
+	uint8_t portid;
+
+	/* init EAL */
+	int ret = rte_eal_init(argc, argv);
+	if (ret < 0)
+		rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
+	argc -= ret;
+	argv += ret;
+
+	nb_ports = rte_eth_dev_count();
+	if (nb_ports < 2 || (nb_ports & 1))
+		rte_exit(EXIT_FAILURE, "Error: number of ports must be even\n");
+
+	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);
+	if (mbuf_pool == NULL)
+		rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");
+
+	/* initialize all ports */
+	for (portid = 0; portid < nb_ports; portid++)
+		if (port_init(portid, mbuf_pool) != 0)
+			rte_exit(EXIT_FAILURE, "Cannot init port %"PRIu8"\n",
+					portid);
+
+	if (rte_lcore_count() > 1)
+		printf("\nWARNING: Too much enabled lcores - App uses only 1 lcore\n");
+
+	/* call lcore_main on master core only */
+	lcore_main();
+	return 0;
+}
diff --git a/examples/rxtx_callbacks/basicfwd.h b/examples/rxtx_callbacks/basicfwd.h
new file mode 100644
index 0000000..3797b5d
--- /dev/null
+++ b/examples/rxtx_callbacks/basicfwd.h
@@ -0,0 +1,46 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 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.
+ */
+
+#ifndef BASICFWD_H
+#define BASICFWD_H
+
+
+#ifdef RTE_EXEC_ENV_BAREMETAL
+#define MAIN _main
+#else
+#define MAIN main
+#endif
+
+int MAIN(int argc, char *argv[]);
+
+#endif /* BASICFWD_H */
-- 
1.9.3