Hi Ma, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git OLK-5.10 head: 45e99bc87727bf5be83ac512da687f7742d4a8fb commit: 6263994761a3d3ad6e5fa3beff9ca8cbd38d3bf3 [2926/2926] mm: thp: Add memory reliable support for hugepaged collapse config: x86_64-randconfig-161-20250527 (https://download.01.org/0day-ci/archive/20250528/202505280046.3lWnWdOg-lkp@i...) compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250528/202505280046.3lWnWdOg-lkp@i...) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202505280046.3lWnWdOg-lkp@intel.com/ All warnings (new ones prefixed by >>): mm/khugepaged.c:102: warning: Function parameter or member 'nr_pte_mapped_thp' not described in 'mm_slot' mm/khugepaged.c:102: warning: Function parameter or member 'pte_mapped_thp' not described in 'mm_slot' mm/khugepaged.c:1443: warning: Function parameter or member 'mm' not described in 'collapse_pte_mapped_thp' mm/khugepaged.c:1443: warning: Function parameter or member 'addr' not described in 'collapse_pte_mapped_thp' mm/khugepaged.c:1646: warning: Function parameter or member 'mm' not described in 'collapse_file' mm/khugepaged.c:1646: warning: Function parameter or member 'file' not described in 'collapse_file' mm/khugepaged.c:1646: warning: Function parameter or member 'start' not described in 'collapse_file' mm/khugepaged.c:1646: warning: Function parameter or member 'hpage' not described in 'collapse_file' mm/khugepaged.c:1646: warning: Function parameter or member 'node' not described in 'collapse_file'
mm/khugepaged.c:1646: warning: Function parameter or member 'reliable' not described in 'collapse_file'
vim +1646 mm/khugepaged.c f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1623 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1624 /** 99cb0dbd47a15d Song Liu 2019-09-23 1625 * collapse_file - collapse filemap/tmpfs/shmem pages into huge one. f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1626 * f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1627 * Basic scheme is simple, details are more complex: 87c460a0bded56 Hugh Dickins 2018-11-30 1628 * - allocate and lock a new huge page; 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1629 * - scan page cache replacing old pages with the new one 99cb0dbd47a15d Song Liu 2019-09-23 1630 * + swap/gup in pages if necessary; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1631 * + fill in gaps; 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1632 * + keep old pages around in case rollback is required; 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1633 * - if replacing succeeds: f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1634 * + copy data over; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1635 * + free old pages; 87c460a0bded56 Hugh Dickins 2018-11-30 1636 * + unlock huge page; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1637 * - if replacing failed; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1638 * + put all pages back and unfreeze them; 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1639 * + restore gaps in the page cache; 87c460a0bded56 Hugh Dickins 2018-11-30 1640 * + unlock and free huge page; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1641 */ 579c571e2efdb8 Song Liu 2019-09-23 1642 static void collapse_file(struct mm_struct *mm, 579c571e2efdb8 Song Liu 2019-09-23 1643 struct file *file, pgoff_t start, 6263994761a3d3 Ma Wupeng 2022-11-11 1644 struct page **hpage, int node, 6263994761a3d3 Ma Wupeng 2022-11-11 1645 bool reliable) f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 @1646 { 579c571e2efdb8 Song Liu 2019-09-23 1647 struct address_space *mapping = file->f_mapping; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1648 gfp_t gfp; 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1649 struct page *new_page; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1650 pgoff_t index, end = start + HPAGE_PMD_NR; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1651 LIST_HEAD(pagelist); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1652 XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1653 int nr_none = 0, result = SCAN_SUCCEED; 99cb0dbd47a15d Song Liu 2019-09-23 1654 bool is_shmem = shmem_file(file); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1655 99cb0dbd47a15d Song Liu 2019-09-23 1656 VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1657 VM_BUG_ON(start & (HPAGE_PMD_NR - 1)); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1658 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1659 /* Only allocate from the target node */ 41b6167e8f746b Michal Hocko 2017-01-10 1660 gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1661 6263994761a3d3 Ma Wupeng 2022-11-11 1662 if (reliable) 6263994761a3d3 Ma Wupeng 2022-11-11 1663 gfp |= GFP_RELIABLE; 6263994761a3d3 Ma Wupeng 2022-11-11 1664 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1665 new_page = khugepaged_alloc_page(hpage, gfp, node); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1666 if (!new_page) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1667 result = SCAN_ALLOC_HUGE_PAGE_FAIL; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1668 goto out; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1669 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1670 d9eb1ea2bf8734 Johannes Weiner 2020-06-03 1671 if (unlikely(mem_cgroup_charge(new_page, mm, gfp))) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1672 result = SCAN_CGROUP_CHARGE_FAIL; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1673 goto out; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1674 } 9d82c69438d0df Johannes Weiner 2020-06-03 1675 count_memcg_page_event(new_page, THP_COLLAPSE_ALLOC); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1676 95feeabb77149f Hugh Dickins 2018-11-30 1677 /* This will be less messy when we use multi-index entries */ 95feeabb77149f Hugh Dickins 2018-11-30 1678 do { 95feeabb77149f Hugh Dickins 2018-11-30 1679 xas_lock_irq(&xas); 95feeabb77149f Hugh Dickins 2018-11-30 1680 xas_create_range(&xas); 95feeabb77149f Hugh Dickins 2018-11-30 1681 if (!xas_error(&xas)) 95feeabb77149f Hugh Dickins 2018-11-30 1682 break; 95feeabb77149f Hugh Dickins 2018-11-30 1683 xas_unlock_irq(&xas); 95feeabb77149f Hugh Dickins 2018-11-30 1684 if (!xas_nomem(&xas, GFP_KERNEL)) { 95feeabb77149f Hugh Dickins 2018-11-30 1685 result = SCAN_FAIL; 95feeabb77149f Hugh Dickins 2018-11-30 1686 goto out; 95feeabb77149f Hugh Dickins 2018-11-30 1687 } 95feeabb77149f Hugh Dickins 2018-11-30 1688 } while (1); 95feeabb77149f Hugh Dickins 2018-11-30 1689 042a30824871fa Hugh Dickins 2018-11-30 1690 __SetPageLocked(new_page); 99cb0dbd47a15d Song Liu 2019-09-23 1691 if (is_shmem) 042a30824871fa Hugh Dickins 2018-11-30 1692 __SetPageSwapBacked(new_page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1693 new_page->index = start; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1694 new_page->mapping = mapping; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1695 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1696 /* 87c460a0bded56 Hugh Dickins 2018-11-30 1697 * At this point the new_page is locked and not up-to-date. 87c460a0bded56 Hugh Dickins 2018-11-30 1698 * It's safe to insert it into the page cache, because nobody would 87c460a0bded56 Hugh Dickins 2018-11-30 1699 * be able to map it or use it in another way until we unlock it. f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1700 */ f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1701 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1702 xas_set(&xas, start); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1703 for (index = start; index < end; index++) { 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1704 struct page *page = xas_next(&xas); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1705 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1706 VM_BUG_ON(index != xas.xa_index); 99cb0dbd47a15d Song Liu 2019-09-23 1707 if (is_shmem) { 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1708 if (!page) { 701270fa193aad Hugh Dickins 2018-11-30 1709 /* 99cb0dbd47a15d Song Liu 2019-09-23 1710 * Stop if extent has been truncated or 99cb0dbd47a15d Song Liu 2019-09-23 1711 * hole-punched, and is now completely 99cb0dbd47a15d Song Liu 2019-09-23 1712 * empty. 701270fa193aad Hugh Dickins 2018-11-30 1713 */ 701270fa193aad Hugh Dickins 2018-11-30 1714 if (index == start) { 701270fa193aad Hugh Dickins 2018-11-30 1715 if (!xas_next_entry(&xas, end - 1)) { 701270fa193aad Hugh Dickins 2018-11-30 1716 result = SCAN_TRUNCATED; 042a30824871fa Hugh Dickins 2018-11-30 1717 goto xa_locked; 701270fa193aad Hugh Dickins 2018-11-30 1718 } 701270fa193aad Hugh Dickins 2018-11-30 1719 xas_set(&xas, index); 701270fa193aad Hugh Dickins 2018-11-30 1720 } 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1721 if (!shmem_charge(mapping->host, 1)) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1722 result = SCAN_FAIL; 042a30824871fa Hugh Dickins 2018-11-30 1723 goto xa_locked; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1724 } 4101196b19d7f9 Matthew Wilcox (Oracle 2019-09-23 1725) xas_store(&xas, new_page); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1726 nr_none++; 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1727 continue; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1728 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1729 3159f943aafdba Matthew Wilcox 2017-11-03 1730 if (xa_is_value(page) || !PageUptodate(page)) { 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1731 xas_unlock_irq(&xas); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1732 /* swap in or instantiate fallocated page */ f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1733 if (shmem_getpage(mapping->host, index, &page, f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1734 SGP_NOHUGE)) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1735 result = SCAN_FAIL; 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1736 goto xa_unlocked; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1737 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1738 } else if (trylock_page(page)) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1739 get_page(page); 042a30824871fa Hugh Dickins 2018-11-30 1740 xas_unlock_irq(&xas); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1741 } else { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1742 result = SCAN_PAGE_LOCK; 042a30824871fa Hugh Dickins 2018-11-30 1743 goto xa_locked; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1744 } 99cb0dbd47a15d Song Liu 2019-09-23 1745 } else { /* !is_shmem */ 99cb0dbd47a15d Song Liu 2019-09-23 1746 if (!page || xa_is_value(page)) { 99cb0dbd47a15d Song Liu 2019-09-23 1747 xas_unlock_irq(&xas); 99cb0dbd47a15d Song Liu 2019-09-23 1748 page_cache_sync_readahead(mapping, &file->f_ra, 99cb0dbd47a15d Song Liu 2019-09-23 1749 file, index, e5a59d308f52bb David Howells 2020-09-04 1750 end - index); 99cb0dbd47a15d Song Liu 2019-09-23 1751 /* drain pagevecs to help isolate_lru_page() */ 99cb0dbd47a15d Song Liu 2019-09-23 1752 lru_add_drain(); 99cb0dbd47a15d Song Liu 2019-09-23 1753 page = find_lock_page(mapping, index); 99cb0dbd47a15d Song Liu 2019-09-23 1754 if (unlikely(page == NULL)) { 99cb0dbd47a15d Song Liu 2019-09-23 1755 result = SCAN_FAIL; 99cb0dbd47a15d Song Liu 2019-09-23 1756 goto xa_unlocked; 99cb0dbd47a15d Song Liu 2019-09-23 1757 } 75f360696ce9d8 Song Liu 2019-11-30 1758 } else if (PageDirty(page)) { 75f360696ce9d8 Song Liu 2019-11-30 1759 /* 75f360696ce9d8 Song Liu 2019-11-30 1760 * khugepaged only works on read-only fd, 75f360696ce9d8 Song Liu 2019-11-30 1761 * so this page is dirty because it hasn't 75f360696ce9d8 Song Liu 2019-11-30 1762 * been flushed since first write. There 75f360696ce9d8 Song Liu 2019-11-30 1763 * won't be new dirty pages. 75f360696ce9d8 Song Liu 2019-11-30 1764 * 75f360696ce9d8 Song Liu 2019-11-30 1765 * Trigger async flush here and hope the 75f360696ce9d8 Song Liu 2019-11-30 1766 * writeback is done when khugepaged 75f360696ce9d8 Song Liu 2019-11-30 1767 * revisits this page. 75f360696ce9d8 Song Liu 2019-11-30 1768 * 75f360696ce9d8 Song Liu 2019-11-30 1769 * This is a one-off situation. We are not 75f360696ce9d8 Song Liu 2019-11-30 1770 * forcing writeback in loop. 75f360696ce9d8 Song Liu 2019-11-30 1771 */ 75f360696ce9d8 Song Liu 2019-11-30 1772 xas_unlock_irq(&xas); 75f360696ce9d8 Song Liu 2019-11-30 1773 filemap_flush(mapping); 75f360696ce9d8 Song Liu 2019-11-30 1774 result = SCAN_FAIL; 75f360696ce9d8 Song Liu 2019-11-30 1775 goto xa_unlocked; ca1ab8b4a53297 Rongwei Wang 2021-11-15 1776 } else if (PageWriteback(page)) { ca1ab8b4a53297 Rongwei Wang 2021-11-15 1777 xas_unlock_irq(&xas); ca1ab8b4a53297 Rongwei Wang 2021-11-15 1778 result = SCAN_FAIL; ca1ab8b4a53297 Rongwei Wang 2021-11-15 1779 goto xa_unlocked; 99cb0dbd47a15d Song Liu 2019-09-23 1780 } else if (trylock_page(page)) { 99cb0dbd47a15d Song Liu 2019-09-23 1781 get_page(page); 99cb0dbd47a15d Song Liu 2019-09-23 1782 xas_unlock_irq(&xas); 99cb0dbd47a15d Song Liu 2019-09-23 1783 } else { 99cb0dbd47a15d Song Liu 2019-09-23 1784 result = SCAN_PAGE_LOCK; 99cb0dbd47a15d Song Liu 2019-09-23 1785 goto xa_locked; 99cb0dbd47a15d Song Liu 2019-09-23 1786 } 99cb0dbd47a15d Song Liu 2019-09-23 1787 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1788 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1789 /* b93b016313b3ba Matthew Wilcox 2018-04-10 1790 * The page must be locked, so we can drop the i_pages lock f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1791 * without racing with truncate. f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1792 */ f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1793 VM_BUG_ON_PAGE(!PageLocked(page), page); 4655e5e5f38726 Song Liu 2019-11-15 1794 4655e5e5f38726 Song Liu 2019-11-15 1795 /* make sure the page is up to date */ 4655e5e5f38726 Song Liu 2019-11-15 1796 if (unlikely(!PageUptodate(page))) { 4655e5e5f38726 Song Liu 2019-11-15 1797 result = SCAN_FAIL; 4655e5e5f38726 Song Liu 2019-11-15 1798 goto out_unlock; 4655e5e5f38726 Song Liu 2019-11-15 1799 } 06a5e1268a5fb9 Hugh Dickins 2018-11-30 1800 06a5e1268a5fb9 Hugh Dickins 2018-11-30 1801 /* 06a5e1268a5fb9 Hugh Dickins 2018-11-30 1802 * If file was truncated then extended, or hole-punched, before 06a5e1268a5fb9 Hugh Dickins 2018-11-30 1803 * we locked the first page, then a THP might be there already. 06a5e1268a5fb9 Hugh Dickins 2018-11-30 1804 */ 06a5e1268a5fb9 Hugh Dickins 2018-11-30 1805 if (PageTransCompound(page)) { 06a5e1268a5fb9 Hugh Dickins 2018-11-30 1806 result = SCAN_PAGE_COMPOUND; 06a5e1268a5fb9 Hugh Dickins 2018-11-30 1807 goto out_unlock; 06a5e1268a5fb9 Hugh Dickins 2018-11-30 1808 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1809 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1810 if (page_mapping(page) != mapping) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1811 result = SCAN_TRUNCATED; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1812 goto out_unlock; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1813 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1814 ca1ab8b4a53297 Rongwei Wang 2021-11-15 1815 if (!is_shmem && (PageDirty(page) || ca1ab8b4a53297 Rongwei Wang 2021-11-15 1816 PageWriteback(page))) { 4655e5e5f38726 Song Liu 2019-11-15 1817 /* 4655e5e5f38726 Song Liu 2019-11-15 1818 * khugepaged only works on read-only fd, so this 4655e5e5f38726 Song Liu 2019-11-15 1819 * page is dirty because it hasn't been flushed 4655e5e5f38726 Song Liu 2019-11-15 1820 * since first write. 4655e5e5f38726 Song Liu 2019-11-15 1821 */ 4655e5e5f38726 Song Liu 2019-11-15 1822 result = SCAN_FAIL; 4655e5e5f38726 Song Liu 2019-11-15 1823 goto out_unlock; 4655e5e5f38726 Song Liu 2019-11-15 1824 } 4655e5e5f38726 Song Liu 2019-11-15 1825 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1826 if (isolate_lru_page(page)) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1827 result = SCAN_DEL_PAGE_LRU; 042a30824871fa Hugh Dickins 2018-11-30 1828 goto out_unlock; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1829 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1830 99cb0dbd47a15d Song Liu 2019-09-23 1831 if (page_has_private(page) && 99cb0dbd47a15d Song Liu 2019-09-23 1832 !try_to_release_page(page, GFP_KERNEL)) { 99cb0dbd47a15d Song Liu 2019-09-23 1833 result = SCAN_PAGE_HAS_PRIVATE; 2f33a706027c94 Hugh Dickins 2020-05-27 1834 putback_lru_page(page); 99cb0dbd47a15d Song Liu 2019-09-23 1835 goto out_unlock; 99cb0dbd47a15d Song Liu 2019-09-23 1836 } 99cb0dbd47a15d Song Liu 2019-09-23 1837 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1838 if (page_mapped(page)) 977fbdcd5986c9 Matthew Wilcox 2018-01-31 1839 unmap_mapping_pages(mapping, index, 1, false); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1840 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1841 xas_lock_irq(&xas); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1842 xas_set(&xas, index); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1843 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1844 VM_BUG_ON_PAGE(page != xas_load(&xas), page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1845 VM_BUG_ON_PAGE(page_mapped(page), page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1846 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1847 /* f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1848 * The page is expected to have page_count() == 3: f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1849 * - we hold a pin on it; 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1850 * - one reference from page cache; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1851 * - one from isolate_lru_page; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1852 */ f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1853 if (!page_ref_freeze(page, 3)) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1854 result = SCAN_PAGE_COUNT; 042a30824871fa Hugh Dickins 2018-11-30 1855 xas_unlock_irq(&xas); 042a30824871fa Hugh Dickins 2018-11-30 1856 putback_lru_page(page); 042a30824871fa Hugh Dickins 2018-11-30 1857 goto out_unlock; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1858 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1859 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1860 /* f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1861 * Add the page to the list to be able to undo the collapse if f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1862 * something go wrong. f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1863 */ f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1864 list_add_tail(&page->lru, &pagelist); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1865 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1866 /* Finally, replace with the new page. */ 4101196b19d7f9 Matthew Wilcox (Oracle 2019-09-23 1867) xas_store(&xas, new_page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1868 continue; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1869 out_unlock: f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1870 unlock_page(page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1871 put_page(page); 042a30824871fa Hugh Dickins 2018-11-30 1872 goto xa_unlocked; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1873 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1874 99cb0dbd47a15d Song Liu 2019-09-23 1875 if (is_shmem) 042a30824871fa Hugh Dickins 2018-11-30 1876 __inc_node_page_state(new_page, NR_SHMEM_THPS); 09d91cda0e8207 Song Liu 2019-09-23 1877 else { 99cb0dbd47a15d Song Liu 2019-09-23 1878 __inc_node_page_state(new_page, NR_FILE_THPS); 09d91cda0e8207 Song Liu 2019-09-23 1879 filemap_nr_thps_inc(mapping); 09d91cda0e8207 Song Liu 2019-09-23 1880 } 99cb0dbd47a15d Song Liu 2019-09-23 1881 042a30824871fa Hugh Dickins 2018-11-30 1882 if (nr_none) { 9d82c69438d0df Johannes Weiner 2020-06-03 1883 __mod_lruvec_page_state(new_page, NR_FILE_PAGES, nr_none); 99cb0dbd47a15d Song Liu 2019-09-23 1884 if (is_shmem) 9d82c69438d0df Johannes Weiner 2020-06-03 1885 __mod_lruvec_page_state(new_page, NR_SHMEM, nr_none); 042a30824871fa Hugh Dickins 2018-11-30 1886 } 042a30824871fa Hugh Dickins 2018-11-30 1887 042a30824871fa Hugh Dickins 2018-11-30 1888 xa_locked: 042a30824871fa Hugh Dickins 2018-11-30 1889 xas_unlock_irq(&xas); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1890 xa_unlocked: 042a30824871fa Hugh Dickins 2018-11-30 1891 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1892 if (result == SCAN_SUCCEED) { 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1893 struct page *page, *tmp; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1894 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1895 /* 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1896 * Replacing old pages with new one has succeeded, now we 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1897 * need to copy the content and free the old pages. f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1898 */ 2af8ff291848cc Hugh Dickins 2018-11-30 1899 index = start; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1900 list_for_each_entry_safe(page, tmp, &pagelist, lru) { 2af8ff291848cc Hugh Dickins 2018-11-30 1901 while (index < page->index) { 2af8ff291848cc Hugh Dickins 2018-11-30 1902 clear_highpage(new_page + (index % HPAGE_PMD_NR)); 2af8ff291848cc Hugh Dickins 2018-11-30 1903 index++; 2af8ff291848cc Hugh Dickins 2018-11-30 1904 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1905 copy_highpage(new_page + (page->index % HPAGE_PMD_NR), f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1906 page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1907 list_del(&page->lru); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1908 page->mapping = NULL; 042a30824871fa Hugh Dickins 2018-11-30 1909 page_ref_unfreeze(page, 1); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1910 ClearPageActive(page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1911 ClearPageUnevictable(page); 042a30824871fa Hugh Dickins 2018-11-30 1912 unlock_page(page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1913 put_page(page); 2af8ff291848cc Hugh Dickins 2018-11-30 1914 index++; 2af8ff291848cc Hugh Dickins 2018-11-30 1915 } 2af8ff291848cc Hugh Dickins 2018-11-30 1916 while (index < end) { 2af8ff291848cc Hugh Dickins 2018-11-30 1917 clear_highpage(new_page + (index % HPAGE_PMD_NR)); 2af8ff291848cc Hugh Dickins 2018-11-30 1918 index++; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1919 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1920 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1921 SetPageUptodate(new_page); 87c460a0bded56 Hugh Dickins 2018-11-30 1922 page_ref_add(new_page, HPAGE_PMD_NR - 1); 6058eaec816f29 Johannes Weiner 2020-06-03 1923 if (is_shmem) 99cb0dbd47a15d Song Liu 2019-09-23 1924 set_page_dirty(new_page); 6058eaec816f29 Johannes Weiner 2020-06-03 1925 lru_cache_add(new_page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1926 042a30824871fa Hugh Dickins 2018-11-30 1927 /* 042a30824871fa Hugh Dickins 2018-11-30 1928 * Remove pte page tables, so we can re-fault the page as huge. 042a30824871fa Hugh Dickins 2018-11-30 1929 */ 042a30824871fa Hugh Dickins 2018-11-30 1930 retract_page_tables(mapping, start); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1931 *hpage = NULL; 87aa752906ecf6 Yang Shi 2018-08-17 1932 87aa752906ecf6 Yang Shi 2018-08-17 1933 khugepaged_pages_collapsed++; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1934 } else { 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1935 struct page *page; aaa52e340073b7 Hugh Dickins 2018-11-30 1936 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1937 /* Something went wrong: roll back page cache changes */ 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1938 xas_lock_irq(&xas); aaa52e340073b7 Hugh Dickins 2018-11-30 1939 mapping->nrpages -= nr_none; 99cb0dbd47a15d Song Liu 2019-09-23 1940 99cb0dbd47a15d Song Liu 2019-09-23 1941 if (is_shmem) aaa52e340073b7 Hugh Dickins 2018-11-30 1942 shmem_uncharge(mapping->host, nr_none); aaa52e340073b7 Hugh Dickins 2018-11-30 1943 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1944 xas_set(&xas, start); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1945 xas_for_each(&xas, page, end - 1) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1946 page = list_first_entry_or_null(&pagelist, f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1947 struct page, lru); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1948 if (!page || xas.xa_index < page->index) { f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1949 if (!nr_none) f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1950 break; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1951 nr_none--; 59749e6ce53735 Johannes Weiner 2016-12-12 1952 /* Put holes back where they were */ 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1953 xas_store(&xas, NULL); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1954 continue; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1955 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1956 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1957 VM_BUG_ON_PAGE(page->index != xas.xa_index, page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1958 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1959 /* Unfreeze the page. */ f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1960 list_del(&page->lru); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1961 page_ref_unfreeze(page, 2); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1962 xas_store(&xas, page); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1963 xas_pause(&xas); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1964 xas_unlock_irq(&xas); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1965 unlock_page(page); 042a30824871fa Hugh Dickins 2018-11-30 1966 putback_lru_page(page); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1967 xas_lock_irq(&xas); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1968 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1969 VM_BUG_ON(nr_none); 77da9389b9d5f0 Matthew Wilcox 2017-12-04 1970 xas_unlock_irq(&xas); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1971 f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1972 new_page->mapping = NULL; f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1973 } 042a30824871fa Hugh Dickins 2018-11-30 1974 042a30824871fa Hugh Dickins 2018-11-30 1975 unlock_page(new_page); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1976 out: f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1977 VM_BUG_ON(!list_empty(&pagelist)); 9d82c69438d0df Johannes Weiner 2020-06-03 1978 if (!IS_ERR_OR_NULL(*hpage)) 9d82c69438d0df Johannes Weiner 2020-06-03 1979 mem_cgroup_uncharge(*hpage); f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1980 /* TODO: tracepoints */ f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1981 } f3f0e1d2150b2b Kirill A. Shutemov 2016-07-26 1982 :::::: The code at line 1646 was first introduced by commit :::::: f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 khugepaged: add support of collapse for tmpfs/shmem pages :::::: TO: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> :::::: CC: Linus Torvalds <torvalds@linux-foundation.org> -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki