在kernel文件夹下make，报kernel/cpuset.c:1380: error: ‘task’ undeclared (first use
in this function)
解决方法task -->tsk
drivers/hello/hello.c:233:2: error: implicit declaration of function ‘init_MUTEX’
解决方法: 注释掉drivers/hello/hello.c:
init_MUTEX(&(dev->sem));