PAGE_MAPPING_KSM  484 include/linux/page-flags.h 				PAGE_MAPPING_KSM;
PAGE_MAPPING_KSM  702 mm/ksm.c       					PAGE_MAPPING_KSM);
PAGE_MAPPING_KSM  868 mm/ksm.c       	page->mapping = (void *)((unsigned long)stable_node | PAGE_MAPPING_KSM);