pthread_create创建的线程与内核线程相同吗? [英] The thread created by pthread_create the same with the kernel thread?

问题描述

我使用以下命令查看系统允许的最大线程数:

I use the command below to view the maximum number of threads my system allows:

# cat /proc/sys/kernel/threads-max

电话号码是772432.

And the number is 772432.

但是，我使用下面的代码创建了100万个线程.而且有效.

However, I use the code below to create 1 million threads. And it works.

#include <pthread.h>
#include <stdio.h>

static unsigned long long thread_nr = 0;

pthread_mutex_t mutex_;

void* inc_thread_nr(void* arg) {
    /* int arr[1024][1024]; */
    (void*)arg;
    pthread_mutex_lock(&mutex_);
    thread_nr ++;
    pthread_mutex_unlock(&mutex_);
}

int main(int argc, char *argv[])
{
    int err;
    int cnt = 0;

    pthread_mutex_init(&mutex_, NULL);

    while (cnt < 1000000) {
        pthread_t pid;
        err = pthread_create(&pid, NULL, (void*)inc_thread_nr, NULL);
        if (err != 0) {
            break;
        }
        pthread_join(pid, NULL);
        cnt++;
    }

    pthread_mutex_destroy(&mutex_);
    printf("Maximum number of threads per process is = %d\n", thread_nr);
}

输出为:

Maximum number of threads per process is = 1000000

，它大于最大线程数.这是什么原因呢?并且pthread_create创建的线程与内核线程是否相同?

which is larger than the maximum number of threads. What is the reason for this? And is the thread create by pthread_create the same with the kernel thread?

我的操作系统是Fedora 16，具有12个内核，48G RAM.

My OS is Fedora 16, with 12 cores, 48G RAM.

推荐答案

您不应使用％d长时间打印未签名的内容.

You should not print your unsigned long long with %d.

使用

printf("... %llu\n", thread_nr);

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