linux 内核空间计算code 运行时间测试

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

static int __init kernel_time_init(void)
{
    int i;
    struct timeval start_time,end_time;
    long cost_time = 0;   
	          
    printk("kernel time test ...\n");
    do_gettimeofday(&start_time);//获取开始时间

	/*延时1s*/
    for(i=0;i<10;i++) {
        mdelay(100);
    }
    do_gettimeofday(&end_time);//获取结束时间

    long secsDiff = end_time.tv_sec - start_time.tv_sec;
    cost_time = secsDiff * 1000000
                   + (end_time.tv_usec - start_time.tv_usec);
    printk("Cost time: %ld us\n", cost_time);

    return 0;
}
 
static void __exit kernel_time_exit(void)
{
     printk("kernel time exit\r\n");
}
 
module_init(kernel_time_init);
module_exit(kernel_time_exit);
 
MODULE_LICENSE("GPL");