map_swap_page     249 include/linux/swap.h extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t);
map_swap_page      33 mm/page_io.c   		bio->bi_sector = map_swap_page(sis, swp_offset(entry)) *
map_swap_page     999 mm/swapfile.c  	return (sis->flags & SWP_WRITEOK) ? map_swap_page(sis, offset) : 0;