使用C语言设置CPU亲和度

一台计算机上可能有多个CPU，如何让程序只在特定的CPU上运行呢？

设置CPU亲和度的API位于头文件<sched.h>中：

vim /usr/include/sched.h

#define _GNU_SOURCE

gcc -D_GNU_SOURCE xx.c

or 

#define __USE_GNU

#include <sched.h>

static int setaffinity(int c)
{
        cpu_set_t cpuset;
        CPU_ZERO(&cpuset);
        CPU_SET(c, &cpuset);
        return sched_setaffinity(0, sizeof(cpuset), &cpuset);
}

测试：

#include <fcntl.h>
#include <unistd.h>
#include <sched.h>

static int setaffinity(int c)
{
        cpu_set_t cpuset;
        CPU_ZERO(&cpuset);
        CPU_SET(c, &cpuset);
        return sched_setaffinity(0, sizeof(cpuset), &cpuset);
}

static void set_test_root(int id, char *test_root)
{
	sprintf(test_root, "%s/%d", fx_opt->root, worker->id);
}

static int pre_work(struct worker *worker)
{
	char test_root[PATH_MAX];
	set_test_root(worker, test_root);
	return mkdir_p(test_root);
}

static int main_work(struct worker *worker)
{
	char test_root[PATH_MAX];
	struct bench *bench = worker->bench;
	uint64_t iter;
	int rc = 0;

	set_test_root(worker, test_root);
	for (iter = 0; !stop; ++iter) {
		char file[PATH_MAX];
		int fd;
		/* create and close */
		snprintf(file, PATH_MAX, "%s/n_inode_alloc-%" PRIu64 ".dat", 
			 test_root, iter);
		if ((fd = open(file, O_CREAT | O_RDWR, S_IRWXU)) == -1)
			goto err_out;
		close(fd);
	}
out:
	worker->works = (double)iter;
	return rc;
err_out:
	stop = 1;
	rc = errno;
	goto out;
}