SPDK进行I/O 操作测量的代码案例-DPDK中文网

以下是一个使用SPDK进行I/O操作测量的代码案例：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <rte_config.h>
#include <rte_eal.h>
#include <rte_mempool.h>

#include "spdk/stdinc.h"
#include "spdk/nvme.h"

#define NUM_IO_REQUESTS 32
#define BLOCK_SIZE 4096

struct io_request {
    struct spdk_nvme_qpair *qpair;
    void *buf;
};

static void submit_io_requests(struct spdk_nvme_qpair *qpair, struct io_request *io_reqs,
                               uint64_t lba_start, uint32_t lba_count)
{
    int i;

    for (i = 0; i < NUM_IO_REQUESTS; ++i) {
        spdk_nvme_ns_cmd_read(qpair, io_reqs[i].buf, lba_start + i,
                              BLOCK_SIZE / sizeof(uint64_t), NULL, 0, 0);
    }

    while (spdk_nvme_qpair_process_completions(qpair, NUM_IO_REQUESTS) != NUM_IO_REQUESTS);

    for (i = 0; i < NUM_IO_REQUESTS; ++i) {
        spdk_nvme_ns_cmd_write(qpair, io_reqs[i].buf, lba_start + i,
                               BLOCK_SIZE / sizeof(uint64_t), NULL, 0, 0);
    }

    while (spdk_nvme_qpair_process_completions(qpair, NUM_IO_REQUESTS) != NUM_IO_REQUESTS);
}

int main(int argc, char **argv)
{
    int ret;
    uint32_t nsid;
    struct spdk_env_opts opts;
    struct spdk_env_params params;
    struct spdk_nvme_ctrlr *ctrlr;
    struct spdk_nvme_ns *ns;
    struct spdk_nvme_qpair *qpair;
    struct rte_mempool *buf_pool;

    uint64_t lba_count = 1024*1024*1024/BLOCK_SIZE; //1GB
    uint64_t io_size = NUM_IO_REQUESTS*BLOCK_SIZE;

    struct io_request io_reqs[NUM_IO_REQUESTS];

    memset(&opts, 0, sizeof(opts));
    opts.name = "spdk_io_test";
    spdk_env_init(&opts);

    memset(&params, 0, sizeof(params));
    params.mem_size = 2048;
    ret = spdk_vtophys_init(&params);
    if (ret) {
        fprintf(stderr, "Unable to initialize vtophys\n");
        return ret;
    }

    ret = spdk_nvme_probe(NULL, NULL, attach_cb, NULL);
    if (ret) {
        fprintf(stderr, "Unable to probe for NVMe devices\n");
        return ret;
   }

   ctrlr = spdk_nvme_connect("nvme0", NULL);
   if (!ctrlr) {
       fprintf(stderr, "Unable to connect to NVMe controller\n");
       return -1;
   }

   nsid = spdk_nvme_ctrlr_get_first_active_ns(ctrlr);
   ns = spdk_nvme_ctrlr_get_ns(ctrlr, nsid);

   buf_pool = rte_pktmbuf_pool_create("buf_pool", 8192,
                                      512 + RTE_PKTMBUF_HEADROOM,
                                      32,
                                      BLOCK_SIZE - RTE_PKTMBUF_HEADROOM,
                                      rte_socket_id());
   if (!buf_pool) {
       fprintf(stderr, "Unable to create mbuf pool\n");
       return -1;
   }

   qpair = spdk_nvme_ctrlr_alloc_io_qpair(ctrlr, NULL, 0);
   if (!qpair) {
       fprintf(stderr, "Unable to allocate IO queue pair\n");
       return -1;
   }

   int i;
   for (i = 0; i < NUM_IO_REQUESTS; ++i) {
       struct rte_mbuf *buf = rte_pktmbuf_alloc(buf_pool);
       io_reqs[i].qpair = qpair;
       io_reqs[i].buf = rte_pktmbuf_mtod_offset(buf, void *, RTE_PKTMBUF_HEADROOM);
   }

   uint64_t lba_start = 0;

   while (lba_start < lba_count) {
       submit_io_requests(qpair, io_reqs, lba_start, NUM_IO_REQUESTS);

       lba_start += NUM_IO_REQUESTS;

       printf("Processed %lu of %lu LBAs\n", lba_start,
              lba_count);
    }

    spdk_nvme_ctrlr_free_io_qpair(qpair);
    spdk_nvme_detach(ctrlr);

    return 0;
}

这个代码案例使用SPDK库进行I/O操作测量。它首先初始化SPDK环境和参数，然后探测NVMe设备并连接到控制器。之后，它分配一个I/O队列对，并创建一些用于I/O请求的缓冲区。接下来，它循环执行读写操作，每次处理NUM_IO_REQUESTS个逻辑块地址(LBA)，直到处理完整个磁盘的所有LBA。最后，它释放队列对和控制器，并返回0表示成功。