could anybody help me on this? thanks! see if we call bitmap_zero(dst, 2), it will do *dst = 0UL and thus clear whole *dst, but what if we intent to clear 2 bits? not 32bits? static inline void bitmap_zero(unsigned long *dst, int nbits) { if (nbits <= BITS_PER_LONG) *dst = 0UL; else { int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); memset(dst, 0, len); } } Ming - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html