Question

我必须在Linux下找到与 NUMA内存页面迁移相关的开销。

您能否告诉我可以使用哪些工具？

如果可能，你可以展示一个例子。

Answer 1

如果您想了解您的系统是否正在进行过多的远程节点内存访问并且您正在使用intel CPU，Intel's PMU有一个名为vtbwrun的实用程序来报告QPI /非核心活动。

如果您想查看执行页面迁移所需的时间，可以衡量numa_move_pages的调用持续时间（由numactl包提供）。

/*
 * Test program to test the moving of a processes pages.
 *
 * (C) 2006 Silicon Graphics, Inc.
 *          Christoph Lameter <clameter@sgi.com>
 */
#include <stdio.h>
#include <stdlib.h>
#include "../numa.h"
#include <unistd.h>
#include <errno.h>

unsigned int pagesize;
unsigned int page_count = 32;

char *page_base;
char *pages;

void **addr;
int *status;
int *nodes;
int errors;
int nr_nodes;

struct bitmask *old_nodes;
struct bitmask *new_nodes;

int main(int argc, char **argv)
{
      int i, rc;

      pagesize = getpagesize();

      nr_nodes = numa_max_node()+1;

      old_nodes = numa_bitmask_alloc(nr_nodes);
        new_nodes = numa_bitmask_alloc(nr_nodes);
        numa_bitmask_setbit(old_nodes, 1);
        numa_bitmask_setbit(new_nodes, 0);

      if (nr_nodes < 2) {
            printf("A minimum of 2 nodes is required for this test.\n");
            exit(1);
      }

      setbuf(stdout, NULL);
      printf("migrate_pages() test ......\n");
      if (argc > 1)
            sscanf(argv[1], "%d", &page_count);

      page_base = malloc((pagesize + 1) * page_count);
      addr = malloc(sizeof(char *) * page_count);
      status = malloc(sizeof(int *) * page_count);
      nodes = malloc(sizeof(int *) * page_count);
      if (!page_base || !addr || !status || !nodes) {
            printf("Unable to allocate memory\n");
            exit(1);
      }

      pages = (void *) ((((long)page_base) & ~((long)(pagesize - 1))) + pagesize);

      for (i = 0; i < page_count; i++) {
            if (i != 2)
                  /* We leave page 2 unallocated */
                  pages[ i * pagesize ] = (char) i;
            addr[i] = pages + i * pagesize;
            nodes[i] = 1;
            status[i] = -123;
      }

      /* Move to starting node */
      rc = numa_move_pages(0, page_count, addr, nodes, status, 0);
      if (rc < 0 && errno != ENOENT) {
            perror("move_pages");
            exit(1);
      }

      /* Verify correct startup locations */
      printf("Page location at the beginning of the test\n");
      printf("------------------------------------------\n");

      numa_move_pages(0, page_count, addr, NULL, status, 0);
      for (i = 0; i < page_count; i++) {
            printf("Page %d vaddr=%p node=%d\n", i, pages + i * pagesize, status[i]);
            if (i != 2 && status[i] != 1) {
                  printf("Bad page state before migrate_pages. Page %d status %d\n",i, status[i]);
                  exit(1);
            }
      }

      /* Move to node zero */
      numa_move_pages(0, page_count, addr, nodes, status, 0);

      printf("\nMigrating the current processes pages ...\n");
      rc = numa_migrate_pages(0, old_nodes, new_nodes);

      if (rc < 0) {
            perror("numa_migrate_pages failed");
            errors++;
      }

      /* Get page state after migration */
      numa_move_pages(0, page_count, addr, NULL, status, 0);
      for (i = 0; i < page_count; i++) {
            printf("Page %d vaddr=%lx node=%d\n", i,
                  (unsigned long)(pages + i * pagesize), status[i]);
            if (i != 2) {
                  if (pages[ i* pagesize ] != (char) i) {
                        printf("*** Page contents corrupted.\n");
                        errors++;
                  } else if (status[i]) {
                        printf("*** Page on the wrong node\n");
                        errors++;
                  }
            }
      }

      if (!errors)
            printf("Test successful.\n");
      else
            printf("%d errors.\n", errors);

      return errors > 0 ? 1 : 0;
}

NUMA内存页面迁移开销

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