GENRADIX_ARY_SHIFT   22 lib/generic-radix-tree.c 	return PAGE_SHIFT + GENRADIX_ARY_SHIFT * depth;
GENRADIX_ARY_SHIFT   35 lib/generic-radix-tree.c 	DIV_ROUND_UP(BITS_PER_LONG - PAGE_SHIFT, GENRADIX_ARY_SHIFT)