unsigned long paddr = (pfn << PAGE_SHIFT);  return paddr < __pa(high_memory); 
return pfn < max_pfn; 
int page_is_ram(unsigned long pfn){	unsigned long paddr = (pfn << PAGE_SHIFT);	return paddr < __pa(high_memory);}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/8b150478aeb1a8edb9015c2f7ac4da637ff65c45/init.c/clean/arch/ppc/mm/init.c