pthread_setaffinity_np

 

// bindcpu.c
// gcc bindcpu.c -o bind -lpthread -std=c99
#define _GNU_SOURCE  //该宏定义必须有
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sched.h>
#include <unistd.h>
#include <pthread.h>

#define CREATE_THREAD_NUMBER 2
#define JUDGE_IS_SUCCESS(RET) (RET == -1)


struct thread_info
{
    pthread_t thread_id;
    int thread_num;
};

void do_thing_busy_cpu()
{
    int j = 0;
    int buf[10240];
    while(j++ < 1024*1024)
    {
        memset(buf, 0, sizeof(buf));
    }
}

void *threadFunc(void *arg)
{
    struct thread_info *subThreadInfo = (struct thread_info *)arg;
    pthread_t subThreadID = subThreadInfo->thread_id;

    printf("begin\n");
    cpu_set_t g_cpuset;  //定义cpu集合
    CPU_ZERO(&g_cpuset); //初始化cpu集合
    CPU_SET(subThreadInfo->thread_num, &g_cpuset); //将编号为subThreadInfo->thread_num的cpu核加到cpuset集合中
    if(JUDGE_IS_SUCCESS(pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t),&g_cpuset)))
    {
        printf("ERROR:set CPU affinity fail!\n");
    }

    printf("while()\n");
    while(1)
    {
        cpu_set_t getCpuset;
        CPU_ZERO(&getCpuset);
        if(JUDGE_IS_SUCCESS(pthread_getaffinity_np(pthread_self() ,sizeof(cpu_set_t),&getCpuset)))
        {
            printf("ERROR:get CPU affinity fail!\n");
        }
        for(int i=0; i<CREATE_THREAD_NUMBER; i++)
        {
            if(CPU_ISSET(i,&getCpuset))
            {
                sleep(1);
                printf("thread %d is running on cpu: %d\n",subThreadInfo->thread_id,i);
                do_thing_busy_cpu();
            }
        }
    }

    return NULL;
}

int main(int argc, char *argv[])
{

    struct thread_info threadInfo[CREATE_THREAD_NUMBER];
    int cpuNum = sysconf(_SC_NPROCESSORS_CONF);
    printf("cpu number:%d\n",cpuNum);

    //创建2个线程
    for(int i=0; i<CREATE_THREAD_NUMBER; i++)
    {
        threadInfo[i].thread_num = i;
        pthread_create(&threadInfo[i].thread_id,NULL,threadFunc,&threadInfo[i]);
    }

    for(int i=0; i<CREATE_THREAD_NUMBER; i++)
    {
        pthread_join(threadInfo[i].thread_id,NULL);
    }
}

~/test/now$ ./bind
cpu number:48
begin
begin
while()
while()
thread 641070848 is running on cpu: 0
thread 632678144 is running on cpu: 1
thread 632678144 is running on cpu: 1
thread 641070848 is running on cpu: 0
thread 641070848 is running on cpu: 0
thread 632678144 is running on cpu: 1
thread 641070848 is running on cpu: 0

..........