按比例吃CPU

前几天测试软件在多核上的性能，需要按照比例吃各个CPU，查了查资料，撸了下面一小段代码；

 #include <unistd.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <time.h>

 #define __USE_GNU
 #include <pthread.h>
 #include <sched.h>

 //CPU ID号
 #define CPU_0 0x0
 #define CPU_1 0x01
 #define CPU_2 0x02
 #define CPU_3 0x03

 //总时间和运行时间
 #define FULL_TIME 100
 #define RUN_TIME 80

 //时钟HZ数
 static clock_t clktck;

 //用户参数输入的吃CPU百分比
 static int eat_cpu_percent;

 //线程绑定CPU
 int attach_cpu(int cpu_index)
 {
     int cpu_num = sysconf(_SC_NPROCESSORS_CONF);
     if (cpu_index <  || cpu_index >= cpu_num)
     {
         perror("cpu index ERROR!\n");
         return -;
     }

     cpu_set_t mask;
     CPU_ZERO(&mask);
     CPU_SET(cpu_index, &mask);

     if (pthread_setaffinity_np(pthread_self(), sizeof(mask), &mask) < )
     {
         perror("set affinity np ERROR!\n");
         return -;
     }

     return ;
 }

 //吃CPU线程
 void *thread_task(void *param)
 {
     int *cpuid = (int *)param;
     if (attach_cpu(*cpuid) < )
     {
         pthread_exit(NULL);
     }

     clock_t time_start;
     clock_t fulltime = FULL_TIME;
     clock_t runtime = eat_cpu_percent;
     while()
     {
         time_start = times(NULL);
         while((times(NULL) - time_start) < runtime);
         usleep((fulltime-runtime) *  *  / clktck);
     }

     pthread_exit(NULL);
 }

 int main(int argc, char *argv[])
 {
     if (argc < )
     {
         printf("Please run with 0-100! Example：./eat_cpu 80\n");
         return -;
     }

     eat_cpu_percent = (atoi)(argv[]);
     if (eat_cpu_percent <  || eat_cpu_percent > )
     {
         printf("eat cpu percent must in range:0-100!\n");
         return -;
     }

     int ret = ;

     clktck = sysconf(_SC_CLK_TCK);

     pthread_t t0;
     int cpuid0 = CPU_0;
     if (pthread_create(&t0, NULL, thread_task, &cpuid0) < )
     {
         perror("create thread 0 ERROR!\n");
         ret = -;
         goto _OUT;
     }

     pthread_t t1;
     int cpuid1 = CPU_1;
     if (pthread_create(&t1, NULL, thread_task, &cpuid1) < )
     {
         perror("create thread 1 ERROR!\n");
         ret = -;
         goto _CANCEL_0;
     }

     pthread_t t2;
     int cpuid2 = CPU_2;
     if (pthread_create(&t2, NULL, thread_task, &cpuid2) < )
     {
         perror("create thread 2 ERROR!\n");
         ret = -;
         goto _CANCEL_1;
     }

     pthread_t t3;
     int cpuid3 = CPU_3;
     if (pthread_create(&t3, NULL, thread_task, &cpuid3) < )
     {
         perror("create thread 3 ERROR!\n");
         ret = -;
         goto _CANCEL_2;
     }

     //直接停这里好了
     while()
     {
         sleep();
     }

 _CANCEL_3:
     pthread_cancel(t3);
     pthread_join(t3, NULL);

 _CANCEL_2:
     pthread_cancel(t2);
     pthread_join(t2, NULL);

 _CANCEL_1:
     pthread_cancel(t1);
     pthread_join(t1, NULL);

 _CANCEL_0:
     pthread_cancel(t0);
     pthread_join(t0, NULL);

 _OUT:
     return ret;
 }