BITMAP_LAST_WORD_MASK
#define BITMAP_LAST_WORD_MASK(n) (~0UL >> (BITS_PER_LONG - (n)))
#define BITMAP_LAST_WORD_MASK(n) (~0UL >> (BITS_PER_LONG - (n)))
#define BITMAP_LAST_WORD_MASK(n) (~0UL >> (BITS_PER_LONG - (n)))