linux(kernel)位操作
#define BIT(nr) (1UL << (nr))#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))#define BIT_WORD(nr) ((nr) / BITS_PER_LONG) #define BITS_PER_LONG 32 test_bit：测试相应地址的nr位是否为1....
