标签：first 数据 set with eal 建议 返回值 用法 quit
#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> #define RX_RING_SIZE 128 //接收环大小 #define TX_RING_SIZE 512 //发送环大小 #define NUM_MBUFS 8191 #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 } }; /* basicfwd.c: Basic DPDK skeleton forwarding example. */ /* * Initializes a given port using global settings and with the RX buffers * coming from the mbuf_pool passed as a parameter. */ /* 指定网口的队列数，本列中指定的是但队列 在tx、rx两个方向上，设置缓冲区 */ static inline int port_init(uint8_t port, struct rte_mempool *mbuf_pool) { struct rte_eth_conf port_conf = port_conf_default; //网口配置=默认的网口配置 const uint16_t rx_rings = 1, tx_rings = 1; //网口tx、rx队列的个数 int retval; //临时变量，返回值 uint16_t q; //临时变量，队列号 if (port >= rte_eth_dev_count()) return -1; /* Configure the Ethernet device. */ //配置以太网口设备 //网口号、发送队列个数、接收队列个数、网口的配置 retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf); //设置网卡设备 if (retval != 0) return retval; /* Allocate and set up 1 RX queue per Ethernet port. */ //RX队列初始化 for (q = 0; q < rx_rings; q++) { //遍历指定网口的所有rx队列 //申请并设置一个收包队列 //指定网口，指定队列，指定队列RING的大小，指定SOCKET_ID号，指定队列选项（默认NULL），指定内存池 //其中rte_eth_dev_socket_id(port)不理解,通过port号来获取dev_socket_id?? //dev_socket_id作用未知，有待研究 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; } //TX队列初始化 /* Allocate and set up 1 TX queue per Ethernet port. */ for (q = 0; q < tx_rings; q++) { //遍历指定网口的所有tx队列 //申请并设置一个发包队列 //指定网口，指定队列，指定队列RING大小，指定SOCKET_ID号，指定选项（NULL为默认） //??TX为何没指定内存池，此特征有待研究 retval = rte_eth_tx_queue_setup(port, q, TX_RING_SIZE, //申请并设置一个发包队列 rte_eth_dev_socket_id(port), NULL); if (retval < 0) return retval; } /* Start the Ethernet port. */ retval = rte_eth_dev_start(port); //启动网卡 if (retval < 0) return retval; /* Display the port MAC address. */ struct ether_addr addr; rte_eth_macaddr_get(port, &addr); //获取网卡的MAC地址，并打印 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]); /* Enable RX in promiscuous mode for the Ethernet device. */ rte_eth_promiscuous_enable(port); //设置网卡为混杂模式 return 0; } /* * The lcore main. This is the main thread that does the work, reading from * an input port and writing to an output port. */ /* //业务函数入口点 //__attribute__((noreturn))用法 //标明函数无返回值 //用来修饰lcore_main函数，标明lcore_main无返回值 */ /* //1、检测CPU与网卡是否匹配 //2、建议使用本地CPU就近网卡？？？，不理解 //3、数据接收、发送的while(1) */ static __attribute__((noreturn)) void lcore_main(void) { const uint8_t nb_ports = rte_eth_dev_count(); //网口总数 uint8_t port; //临时变量，网口号 /* * Check that the port is on the same NUMA node as the polling thread * for best performance. * 检测CPU和网口是否匹配 * ？？？？，不理解，姑且看作是一个检测机制 */ for (port = 0; port < nb_ports; port++) //遍历所有网口 if (rte_eth_dev_socket_id(port) > 0 && //检测的IF语句 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. */ /*运行 直到 应用程序 推出 或 被kill*/ 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. * 从Eth接收数据包 ，并发送到 ETH上。 * 发送顺序为：0 的接收 到 1的 发送， * 1 的接收 到 0的 发送 * 每两个端口为一对 */ for (port = 0; port < nb_ports; port++) { //遍历所有网口 /* Get burst of RX packets, from first port of pair. */ struct rte_mbuf *bufs[BURST_SIZE]; //收包，接收到nb_tx个包 //端口，队列，收包队列，队列大小 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. */ //发包，发送nb_rx个包 //端口，队列，发送缓冲区，发包个数 const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0, bufs, nb_rx); //*****注意：以上流程为：从x收到的包，发送到x^1口 //其中，0^1 = 1, 1^1 = 0 //此运算可以达到测试要求的收、发包逻辑 /* Free any unsent packets. */ //释放不发送的数据包 //1、收到nb_rx个包，转发了nb_tx个，剩余nb_rx-nb_tx个 //2、把剩余的包释放掉 if (unlikely(nb_tx < nb_rx)) { uint16_t buf; for (buf = nb_tx; buf < nb_rx; buf++) rte_pktmbuf_free(bufs[buf]); //释放包 } } } } /* * The main function, which does initialization and calls the per-lcore * functions. */ int main(int argc, char *argv[]) { struct rte_mempool *mbuf_pool; //指向内存池结构的指针变量 unsigned nb_ports; //网口个数 uint8_t portid; //网口号，临时的标记变量 /* Initialize the Environment Abstraction Layer (EAL). */ int ret = rte_eal_init(argc, argv); //初始化 if (ret < 0) rte_exit(EXIT_FAILURE, "Error with EAL initialization\n"); argc -= ret; //??本操作莫名其妙,似乎一点用处也没有 argv += ret; //??本操作莫名其妙,似乎一点用处也没有 /* Check that there is an even number of ports to send/receive on. */ nb_ports = rte_eth_dev_count(); //获取当前有效网口的个数 if (nb_ports < 2 || (nb_ports & 1)) //如果有效网口数小于2或有效网口数为奇数0，则出错 rte_exit(EXIT_FAILURE, "Error: number of ports must be even\n"); /* Creates a new mempool in memory to hold the mbufs. */ /*创建一个新的内存池*/ //"MBUF_POOL"内存池名, NUM_MBUFS * nb_ports网口数, // MBUF_CACHE_SIZE ??, 0, RTE_MBUF_DEFAULT_BUF_SIZE ??, rte_socket_id()?? //此函数为rte_mempoll_create()的封装 //此函数疑惑比较多，需要进一步看代码，先放着 mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL", NUM_MBUFS * nb_ports, MBUF_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id()); if (mbuf_pool == NULL) rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n"); //初始化所有的网口 /* Initialize all ports. */ for (portid = 0; portid < nb_ports; portid++) //遍历所有网口 if (port_init(portid, mbuf_pool) != 0) //初始化指定网口，需要网口号和内存池，此函数为自定义函数，看前面定义 rte_exit(EXIT_FAILURE, "Cannot init port %"PRIu8 "\n", portid); //如果逻辑核心总数>1 ,打印警告信息，此程序用不上多个逻辑核心 //逻辑核心可以通过传递参数 -c 逻辑核掩码来设置 if (rte_lcore_count() > 1) printf("\nWARNING: Too many lcores enabled. Only 1 used.\n"); /* Call lcore_main on the master core only. */ //执行主函数 lcore_main(); return 0; }
标签：first 数据 set with eal 建议 返回值 用法 quit
原文地址：http://www.cnblogs.com/vrg0/p/6956469.html
