Linux 栈空间限制 （ulimit -a指令查看限制）（我的ubuntu下每个线程最多只能申请8M栈空间）

Posted 2022-08-10 Dontla

参考文章：Linux程序栈空间是多大？

我的测试代码：
开启两个线程，每个线程每秒申请1M的栈空间

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

void testStackSize(int index)

    char localValArr[1024*1024] = 0;
    index++;
    printf("%s %d num = %d!\\n", __FUNCTION__, __LINE__, index);
    sleep(1);
    testStackSize(index);


void *threadEntry(void *arg)

    printf("%s %d!\\n", __FUNCTION__, __LINE__);
    printf("New process:  PID: %d,TID: %lu.\\n",getpid(),pthread_self());
    testStackSize(0);
    pthread_exit(NULL);


int main(int argc, char **argv)

    pthread_t thread1;
    pthread_t thread2;
    pthread_create(&thread1, NULL, threadEntry, NULL);
    pthread_create(&thread2, NULL, threadEntry, NULL);
    pthread_join(thread1, NULL);
    pthread_join(thread2, NULL);
    return 0;

ubuntu上编译运行：

[root@ubuntu /arnold_test/test]37# gcc test_stack.c -lpthread
[root@ubuntu /arnold_test/test]38# 
[root@ubuntu /arnold_test/test]38# ./a.out 
threadEntry 17!
New process:  PID: 35664,TID: 140456138036992.
threadEntry 17!
New process:  PID: 35664,TID: 140456129644288.
testStackSize 10 num = 1!
testStackSize 10 num = 1!
testStackSize 10 num = 2!
testStackSize 10 num = 2!
testStackSize 10 num = 3!
testStackSize 10 num = 3!
testStackSize 10 num = 4!
testStackSize 10 num = 4!
testStackSize 10 num = 5!
testStackSize 10 num = 5!
testStackSize 10 num = 6!
testStackSize 10 num = 6!
testStackSize 10 num = 7!
testStackSize 10 num = 7!
段错误 (核心已转储)

测试发现，当每个线程申请到8M（以先申请到的为准）栈空间的时候，就会core dump（吐核）

用ulimit -a查看我系统栈空间的限制：发现栈空间限制为8192kb，就是说每个线程最多只能申请8M的栈空间

[root@ubuntu /arnold_test/test]40# ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 15445
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 15445
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited