if (!pfn_valid(pfn)) 
if (unlikely(!pfn_valid(pfn))) { print_bad_pte(vma, *pte, addr); 
static void msync_pte_range(struct vm_area_struct *vma, pmd_t *pmd,				unsigned long addr, unsigned long end){	pte_t *pte;	int progress = 0;again:	pte = pte_offset_map(pmd, addr);	do {		unsigned long pfn;		struct page *page;		if (progress >= 64) {			progress = 0;			if (need_resched() ||			    need_lockbreak(&vma->vm_mm->page_table_lock))				break;		}		progress++;		if (!pte_present(*pte))			continue;		if (!pte_maybe_dirty(*pte))			continue;		pfn = pte_pfn(*pte);		if (!pfn_valid(pfn))			continue;		page = pfn_to_page(pfn);		if (PageReserved(page))			continue;		if (ptep_clear_flush_dirty(vma, addr, pte) ||		    page_test_and_clear_dirty(page))			set_page_dirty(page);		progress += 3;	} while (pte++, addr += PAGE_SIZE, addr != end);	pte_unmap(pte - 1);	cond_resched_lock(&vma->vm_mm->page_table_lock);	if (addr != end)		goto again;}
10457	/local/tlutelli/issta_data/temp/c/2005_temp/2005/10457/b5810039a54e5babf428e9a1e89fc1940fabff11/msync.c/clean/mm/msync.c