DPDK學習筆記源代碼分析（1）

源代碼分析（1）helloworld

源代碼：

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#include 
#include 
#include 
#include 
#include 

#include 
#include 
#include 
#include 
#include 
#include 
#include 

static int
lcore_hello(__attribute__((unused)) void *arg)
{
	unsigned lcore_id;
	lcore_id = rte_lcore_id();
	printf("hello from core %u\n", lcore_id);
	return 0;
}

int
main(int argc, char **argv)
{
	int ret;
	unsigned lcore_id;

	ret = rte_eal_init(argc, argv);
	if (ret < 0)
		rte_panic("Cannot init EAL\n");

	/* call lcore_hello() on every slave lcore */
	RTE_LCORE_FOREACH_SLAVE(lcore_id) {
		rte_eal_remote_launch(lcore_hello, NULL, lcore_id);
	}

	/* call it on master lcore too */
	lcore_hello(NULL);

	rte_eal_mp_wait_lcore();
	return 0;
}

分析：

helloworld爲dpdk的入門樣例程序，程序的編寫和系統編程一樣都是從main函數作爲入口函數。

rte_eal_init()啓動基礎運行環境，該函數完成的工作比較複雜，讀取入口參數，解析並保存DPDK運行的系統信息，並根據這些信息構建包處理的運行環境。

配置初始化

內存初始化

內存池初始化

隊列初始化

警告初始化

中斷初始化

PCI初始化

定時器初始化

…………

使用DPDK這些操作已經被EAL封裝，如果需要進行深度定製二次開發，則需要進一步的研究。

RTE_LCORE_FOREACH_SLAVE(lcore_id) {
		rte_eal_remote_launch(lcore_hello, NULL, lcore_id);
	}

	DPDK面向多核設計，程序試圖獨佔運行在邏輯核（lcore）上，RTE_LCORE_FOREACH_SLAVE遍歷EAL指定的可用邏輯核，然後在每個邏輯核上執行被指定的線程，本文中爲

lcore_hello。（大家可以執行設計lcore_hello）。