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