fs/proc/task_mmu.c

372  * page is divided by the number of processes sharing it.  So if a
380  * A shift of 12 before division means (assuming 4K page size):
443 static void smaps_account(struct mem_size_stats *mss, struct page *page,
447 	struct folio *folio = page_folio(page);
448 	int i, nr = compound ? compound_nr(page) : 1;
453 	 * of the compound page.
472 	 * differ page-by-page.
474 	 * refcount == 1 guarantees the page is mapped exactly once.
475 	 * If any subpage of the compound page mapped with PTE it would elevate
479 	 * Without holding the page lock this snapshot can be slightly wrong as
481 	 * call page_mapcount() even with PTL held if the page is not mapped,
490 	for (i = 0; i < nr; i++, page++) {
491 		int mapcount = page_mapcount(page);
533 	struct page *page = NULL;
538 		page = vm_normal_page(vma, addr, ptent);
560 			page = pfn_swap_entry_to_page(swpent);
567 	if (!page)
570 	smaps_account(mss, page, false, young, dirty, locked, migration);
580 	struct page *page = NULL;
585 		page = vm_normal_page_pmd(vma, addr, *pmd);
591 			page = pfn_swap_entry_to_page(entry);
594 	if (IS_ERR_OR_NULL(page))
596 	folio = page_folio(page);
606 	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
792 		 * object, so we have to distinguish them during the page walk.
1086 	struct page *page;
1094 	page = vm_normal_page(vma, addr, pte);
1095 	if (!page)
1097 	return page_maybe_dma_pinned(page);
1412 	struct page *page = NULL;
1419 		page = vm_normal_page(vma, addr, pte);
1447 			page = pfn_swap_entry_to_page(entry);
1452 	if (page && !PageAnon(page))
1454 	if (page && !migration && page_mapcount(page) == 1)
1477 		struct page *page = NULL;
1483 			page = pmd_page(pmd);
1516 			page = pfn_swap_entry_to_page(entry);
1520 		if (page && !migration && page_mapcount(page) == 1)
1630  * For each page in the address space, this file contains one 64-bit entry
1633  * Bits 0-54  page frame number (PFN) if present
1637  * Bit  56    page exclusively mapped
1640  * Bit  61    page is file-page or shared-anon
1641  * Bit  62    page swapped
1642  * Bit  63    page present
1644  * If the page is not present but in swap, then the PFN contains an
1645  * encoding of the swap file number and the page's offset into the
1789 		struct page *page;
1796 			page = vm_normal_page(vma, addr, pte);
1797 			if (page && !PageAnon(page))
1851 		struct page *page;
1858 			page = vm_normal_page_pmd(vma, addr, pmd);
1859 			if (page && !PageAnon(page))
1910 	 * page cannot be swapped. So PAGE_IS_FILE is not checked for
2132 	 * Break huge page into small pages if the WP operation
2133 	 * needs to be performed on a portion of the huge page.
2295 		/* Partial HugeTLB page WP isn't possible. */
2557 static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty,
2560 	struct folio *folio = page_folio(page);
2561 	int count = page_mapcount(page);
2585 static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
2588 	struct page *page;
2594 	page = vm_normal_page(vma, addr, pte);
2595 	if (!page || is_zone_device_page(page))
2598 	if (PageReserved(page))
2601 	nid = page_to_nid(page);
2605 	return page;
2609 static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
2613 	struct page *page;
2619 	page = vm_normal_page_pmd(vma, addr, pmd);
2620 	if (!page)
2623 	if (PageReserved(page))
2626 	nid = page_to_nid(page);
2630 	return page;
2646 		struct page *page;
2648 		page = can_gather_numa_stats_pmd(*pmd, vma, addr);
2649 		if (page)
2650 			gather_stats(page, md, pmd_dirty(*pmd),
2663 		struct page *page = can_gather_numa_stats(ptent, vma, addr);
2664 		if (!page)
2666 		gather_stats(page, md, pte_dirty(ptent), 1);
2679 	struct page *page;
2684 	page = pte_page(huge_pte);
2687 	gather_stats(page, md, pte_dirty(huge_pte), 1);