2.34 glibc 接口性能下降问题

对比glibc 2.34和glibc 2.28，fstat接口性能有所下降。
测试文件：
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>

int
main(int argc, char *argv[])
{
    struct stat sb;
    int i = 0;
    for(i;i<50000;i++)
    {
       if (fstat(0, &sb) == -1) {
            perror("stat");
        }
     }
}

测试结果：
fstat的性能对比：
2.34
[root@localhost home]# time ./a.out

real 0m0.055s
user 0m0.017s
sys 0m0.037s
[root@localhost home]# time ./a.out

real 0m0.054s
user 0m0.020s
sys 0m0.034s
[root@localhost home]# time ./a.out

real 0m0.055s
user 0m0.011s
sys 0m0.043s
[root@localhost home]# time ./a.out

real 0m0.054s
user 0m0.017s
sys 0m0.037s

2.28
[root@localhost home]# time ./a.out

real 0m0.041s
user 0m0.019s
sys 0m0.022s
[root@localhost home]# time ./a.out

real 0m0.041s
user 0m0.021s
sys 0m0.020s
[root@localhost home]# time ./a.out

real 0m0.041s
user 0m0.017s
sys 0m0.024s
[root@localhost home]# time ./a.out

real 0m0.041s
user 0m0.019s
sys 0m0.023s

这是什么原因？麻烦解决一下

src-openEuler/glibc

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