bitmap_ord_to_pos(9) centos man page | unix.com

BITMAP_ORD_TO_POS(9)					  Basic Kernel Library Functions				      BITMAP_ORD_TO_POS(9)

NAME
       bitmap_ord_to_pos - find position of n-th set bit in bitmap

SYNOPSIS
       int bitmap_ord_to_pos(const unsigned long * buf, int ord, int bits);

ARGUMENTS
       buf
	   pointer to bitmap

       ord
	   ordinal bit position (n-th set bit, n >= 0)

       bits
	   number of valid bit positions in buf

DESCRIPTION
       Map the ordinal offset of bit ord in buf to its position in buf. Value of ord should be in range 0 <= ord < weight(buf), else results are
       undefined.

       If for example, just bits 4 through 7 are set in buf, then ord values 0 through 3 will get mapped to 4 through 7, respectively, and all
       other ord values return undefined values. When ord value 3 gets mapped to (returns) pos value 7 in this example, that means that the 3rd
       set bit (starting with 0th) is at position 7 in buf.

       The bit positions 0 through bits are valid positions in buf.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						      BITMAP_ORD_TO_POS(9)