ZONES_SHIFT        16 include/linux/page-flags-layout.h #define ZONES_SHIFT 0
ZONES_SHIFT        18 include/linux/page-flags-layout.h #define ZONES_SHIFT 1
ZONES_SHIFT        20 include/linux/page-flags-layout.h #define ZONES_SHIFT 2
ZONES_SHIFT        22 include/linux/page-flags-layout.h #define ZONES_SHIFT 3