Hi Baolin, I love your patch! Yet something to improve: [auto build test ERROR on akpm-mm/mm-everything] [also build test ERROR on next-20220506] [cannot apply to hnaz-mm/master arm64/for-next/core linus/master v5.18-rc5] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/intel-lab-lkp/linux/commits/Baolin-Wang/Fix-CONT-PTE-PMD-size-hugetlb-issue-when-unmapping-or-migrating/20220508-174036 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything config: x86_64-randconfig-a013 (https://download.01.org/0day-ci/archive/20220508/202205081910.mStoC5rj-lkp@xxxxxxxxx/config) compiler: gcc-11 (Debian 11.2.0-20) 11.2.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/907981b27213707fdb2f8a24c107d6752a09a773 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Baolin-Wang/Fix-CONT-PTE-PMD-size-hugetlb-issue-when-unmapping-or-migrating/20220508-174036 git checkout 907981b27213707fdb2f8a24c107d6752a09a773 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): mm/rmap.c: In function 'try_to_migrate_one': >> mm/rmap.c:1931:34: error: implicit declaration of function 'huge_ptep_clear_flush'; did you mean 'ptep_clear_flush'? [-Werror=implicit-function-declaration] 1931 | pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); | ^~~~~~~~~~~~~~~~~~~~~ | ptep_clear_flush >> mm/rmap.c:1931:34: error: incompatible types when assigning to type 'pte_t' from type 'int' >> mm/rmap.c:2023:41: error: implicit declaration of function 'set_huge_pte_at'; did you mean 'set_huge_swap_pte_at'? [-Werror=implicit-function-declaration] 2023 | set_huge_pte_at(mm, address, pvmw.pte, pteval); | ^~~~~~~~~~~~~~~ | set_huge_swap_pte_at cc1: some warnings being treated as errors vim +1931 mm/rmap.c 1883 1884 /* Unexpected PMD-mapped THP? */ 1885 VM_BUG_ON_FOLIO(!pvmw.pte, folio); 1886 1887 subpage = folio_page(folio, 1888 pte_pfn(*pvmw.pte) - folio_pfn(folio)); 1889 address = pvmw.address; 1890 anon_exclusive = folio_test_anon(folio) && 1891 PageAnonExclusive(subpage); 1892 1893 if (folio_test_hugetlb(folio)) { 1894 /* 1895 * huge_pmd_unshare may unmap an entire PMD page. 1896 * There is no way of knowing exactly which PMDs may 1897 * be cached for this mm, so we must flush them all. 1898 * start/end were already adjusted above to cover this 1899 * range. 1900 */ 1901 flush_cache_range(vma, range.start, range.end); 1902 1903 if (!folio_test_anon(folio)) { 1904 /* 1905 * To call huge_pmd_unshare, i_mmap_rwsem must be 1906 * held in write mode. Caller needs to explicitly 1907 * do this outside rmap routines. 1908 */ 1909 VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); 1910 1911 if (huge_pmd_unshare(mm, vma, &address, pvmw.pte)) { 1912 flush_tlb_range(vma, range.start, range.end); 1913 mmu_notifier_invalidate_range(mm, range.start, 1914 range.end); 1915 1916 /* 1917 * The ref count of the PMD page was dropped 1918 * which is part of the way map counting 1919 * is done for shared PMDs. Return 'true' 1920 * here. When there is no other sharing, 1921 * huge_pmd_unshare returns false and we will 1922 * unmap the actual page and drop map count 1923 * to zero. 1924 */ 1925 page_vma_mapped_walk_done(&pvmw); 1926 break; 1927 } 1928 } 1929 1930 /* Nuke the hugetlb page table entry */ > 1931 pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); 1932 } else { 1933 flush_cache_page(vma, address, pte_pfn(*pvmw.pte)); 1934 /* Nuke the page table entry. */ 1935 pteval = ptep_clear_flush(vma, address, pvmw.pte); 1936 } 1937 1938 /* Set the dirty flag on the folio now the pte is gone. */ 1939 if (pte_dirty(pteval)) 1940 folio_mark_dirty(folio); 1941 1942 /* Update high watermark before we lower rss */ 1943 update_hiwater_rss(mm); 1944 1945 if (folio_is_zone_device(folio)) { 1946 unsigned long pfn = folio_pfn(folio); 1947 swp_entry_t entry; 1948 pte_t swp_pte; 1949 1950 if (anon_exclusive) 1951 BUG_ON(page_try_share_anon_rmap(subpage)); 1952 1953 /* 1954 * Store the pfn of the page in a special migration 1955 * pte. do_swap_page() will wait until the migration 1956 * pte is removed and then restart fault handling. 1957 */ 1958 entry = pte_to_swp_entry(pteval); 1959 if (is_writable_device_private_entry(entry)) 1960 entry = make_writable_migration_entry(pfn); 1961 else if (anon_exclusive) 1962 entry = make_readable_exclusive_migration_entry(pfn); 1963 else 1964 entry = make_readable_migration_entry(pfn); 1965 swp_pte = swp_entry_to_pte(entry); 1966 1967 /* 1968 * pteval maps a zone device page and is therefore 1969 * a swap pte. 1970 */ 1971 if (pte_swp_soft_dirty(pteval)) 1972 swp_pte = pte_swp_mksoft_dirty(swp_pte); 1973 if (pte_swp_uffd_wp(pteval)) 1974 swp_pte = pte_swp_mkuffd_wp(swp_pte); 1975 set_pte_at(mm, pvmw.address, pvmw.pte, swp_pte); 1976 trace_set_migration_pte(pvmw.address, pte_val(swp_pte), 1977 compound_order(&folio->page)); 1978 /* 1979 * No need to invalidate here it will synchronize on 1980 * against the special swap migration pte. 1981 * 1982 * The assignment to subpage above was computed from a 1983 * swap PTE which results in an invalid pointer. 1984 * Since only PAGE_SIZE pages can currently be 1985 * migrated, just set it to page. This will need to be 1986 * changed when hugepage migrations to device private 1987 * memory are supported. 1988 */ 1989 subpage = &folio->page; 1990 } else if (PageHWPoison(subpage)) { 1991 pteval = swp_entry_to_pte(make_hwpoison_entry(subpage)); 1992 if (folio_test_hugetlb(folio)) { 1993 hugetlb_count_sub(folio_nr_pages(folio), mm); 1994 set_huge_swap_pte_at(mm, address, 1995 pvmw.pte, pteval, 1996 vma_mmu_pagesize(vma)); 1997 } else { 1998 dec_mm_counter(mm, mm_counter(&folio->page)); 1999 set_pte_at(mm, address, pvmw.pte, pteval); 2000 } 2001 2002 } else if (pte_unused(pteval) && !userfaultfd_armed(vma)) { 2003 /* 2004 * The guest indicated that the page content is of no 2005 * interest anymore. Simply discard the pte, vmscan 2006 * will take care of the rest. 2007 * A future reference will then fault in a new zero 2008 * page. When userfaultfd is active, we must not drop 2009 * this page though, as its main user (postcopy 2010 * migration) will not expect userfaults on already 2011 * copied pages. 2012 */ 2013 dec_mm_counter(mm, mm_counter(&folio->page)); 2014 /* We have to invalidate as we cleared the pte */ 2015 mmu_notifier_invalidate_range(mm, address, 2016 address + PAGE_SIZE); 2017 } else { 2018 swp_entry_t entry; 2019 pte_t swp_pte; 2020 2021 if (arch_unmap_one(mm, vma, address, pteval) < 0) { 2022 if (folio_test_hugetlb(folio)) > 2023 set_huge_pte_at(mm, address, pvmw.pte, pteval); 2024 else 2025 set_pte_at(mm, address, pvmw.pte, pteval); 2026 ret = false; 2027 page_vma_mapped_walk_done(&pvmw); 2028 break; 2029 } 2030 VM_BUG_ON_PAGE(pte_write(pteval) && folio_test_anon(folio) && 2031 !anon_exclusive, subpage); 2032 if (anon_exclusive && 2033 page_try_share_anon_rmap(subpage)) { 2034 if (folio_test_hugetlb(folio)) 2035 set_huge_pte_at(mm, address, pvmw.pte, pteval); 2036 else 2037 set_pte_at(mm, address, pvmw.pte, pteval); 2038 ret = false; 2039 page_vma_mapped_walk_done(&pvmw); 2040 break; 2041 } 2042 2043 /* 2044 * Store the pfn of the page in a special migration 2045 * pte. do_swap_page() will wait until the migration 2046 * pte is removed and then restart fault handling. 2047 */ 2048 if (pte_write(pteval)) 2049 entry = make_writable_migration_entry( 2050 page_to_pfn(subpage)); 2051 else if (anon_exclusive) 2052 entry = make_readable_exclusive_migration_entry( 2053 page_to_pfn(subpage)); 2054 else 2055 entry = make_readable_migration_entry( 2056 page_to_pfn(subpage)); 2057 2058 swp_pte = swp_entry_to_pte(entry); 2059 if (pte_soft_dirty(pteval)) 2060 swp_pte = pte_swp_mksoft_dirty(swp_pte); 2061 if (pte_uffd_wp(pteval)) 2062 swp_pte = pte_swp_mkuffd_wp(swp_pte); 2063 if (folio_test_hugetlb(folio)) 2064 set_huge_swap_pte_at(mm, address, pvmw.pte, 2065 swp_pte, vma_mmu_pagesize(vma)); 2066 else 2067 set_pte_at(mm, address, pvmw.pte, swp_pte); 2068 trace_set_migration_pte(address, pte_val(swp_pte), 2069 compound_order(&folio->page)); 2070 /* 2071 * No need to invalidate here it will synchronize on 2072 * against the special swap migration pte. 2073 */ 2074 } 2075 2076 /* 2077 * No need to call mmu_notifier_invalidate_range() it has be 2078 * done above for all cases requiring it to happen under page 2079 * table lock before mmu_notifier_invalidate_range_end() 2080 * 2081 * See Documentation/vm/mmu_notifier.rst 2082 */ 2083 page_remove_rmap(subpage, vma, folio_test_hugetlb(folio)); 2084 if (vma->vm_flags & VM_LOCKED) 2085 mlock_page_drain_local(); 2086 folio_put(folio); 2087 } 2088 2089 mmu_notifier_invalidate_range_end(&range); 2090 2091 return ret; 2092 } 2093 -- 0-DAY CI Kernel Test Service https://01.org/lkp
