n = 0;
static unsigned count_data_pages(void){	struct zone *zone;	unsigned long zone_pfn;	unsigned n;	n = 0;	for_each_zone (zone) {		if (is_highmem(zone))			continue;		mark_free_pages(zone);		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)			n += saveable(zone, &zone_pfn);	}	return n;}