Linux RedHat kernel: what kernel is best?

#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>

int main( int args, char* argv[])
{
    pid_t spid = getpid();
    if( args == 1 )
        printf( "\n\n[%d]: Parent process started\n", spid);
    else if( args == 3 )
    {
        printf( "[%d]: Child process started\n", spid);
        sleep( 15);
        
        printf( "[%d]: Child process done!!!\n", spid);

        return 0;
    }

    pid_t pid = fork();
  int status;

  switch( pid )
  {
  case -1:
        printf( "[%d] fork failed.\n", spid);
        exit( 0);

    case 0:
    {
            pid_t pid = getpid();
            printf( "[%d]->[%d] Child forked\n", spid, pid);

            int hOutFile = creat( "test.out", S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH
| S_IWOTH);

            int rl = lockf( hOutFile, F_LOCK, 100);
            if( !rl )
                printf( "[%d]->[%d] File 'test.out' locked\n", spid, pid);
            else
            {
                printf( "[%d]->[%d] File 'test.out' did not lock, process failed\n", spid
, pid);
                exit( 0);
            }

        if( execl( argv[0], argv[0], "-child", "-pending", NULL) == -1 )
        {
                printf( "[%d]->[%d] Execute '%s' failed\n", spid, pid, argv[0]);
                exit( 0);
        }
        }
    default:
printf( "[%d] Parent forked\n", spid);
        break;
    }
    printf( "[%d] Sleep 10 seconds.\n", spid);

    sleep( 10);
    printf( "[%d] Check lock (should be locked!).\n", spid);

    int hOutFile = open( "test.out", O_RDONLY);

    int rl = lockf( hOutFile, F_TEST, 100);
    printf( "[%d] Lock of file '%d' is %d.\n", spid, hOutFile, rl);

    printf( "[%d] Sleep 10 seconds.\n", spid);
    sleep( 10);

    printf( "[%d] Wake up!, check lock (should be NOT locked!).\n", spid);
    rl = lockf( hOutFile, F_TEST, 100);
    printf( "[%d] Lock of file '%d' is %d.\n", spid, hOutFile, rl);

    printf( "[%d] Parent Done!!!\n", spid);
    return 0;
}