CC: kbuild-...@lists.01.org BCC: l...@intel.com CC: linux-ker...@vger.kernel.org TO: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
tree: https://github.com/intel/tdx.git guest-unaccepted-memory head: 83a8442434ff3bbf432df7508f1fefd447ca2c86 commit: 0845556ccd9555f5245d3bdd6cb646c2ea3fa9c2 [3/15] mm: Add support for unaccepted memory :::::: branch date: 2 days ago :::::: commit date: 7 days ago config: i386-randconfig-m031-20220509 (https://download.01.org/0day-ci/archive/20220513/202205130113.xdkf4oqn-...@intel.com/config) compiler: gcc-11 (Debian 11.2.0-20) 11.2.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <l...@intel.com> Reported-by: Dan Carpenter <dan.carpen...@oracle.com> smatch warnings: mm/page_alloc.c:1183 __free_one_page() error: uninitialized symbol 'page_needs_acceptance'. vim +/page_needs_acceptance +1183 mm/page_alloc.c 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1056 ^1da177e4c3f41 Linus Torvalds 2005-04-16 1057 /* ^1da177e4c3f41 Linus Torvalds 2005-04-16 1058 * Freeing function for a buddy system allocator. ^1da177e4c3f41 Linus Torvalds 2005-04-16 1059 * ^1da177e4c3f41 Linus Torvalds 2005-04-16 1060 * The concept of a buddy system is to maintain direct-mapped table ^1da177e4c3f41 Linus Torvalds 2005-04-16 1061 * (containing bit values) for memory blocks of various "orders". ^1da177e4c3f41 Linus Torvalds 2005-04-16 1062 * The bottom level table contains the map for the smallest allocatable ^1da177e4c3f41 Linus Torvalds 2005-04-16 1063 * units of memory (here, pages), and each level above it describes ^1da177e4c3f41 Linus Torvalds 2005-04-16 1064 * pairs of units from the levels below, hence, "buddies". ^1da177e4c3f41 Linus Torvalds 2005-04-16 1065 * At a high level, all that happens here is marking the table entry ^1da177e4c3f41 Linus Torvalds 2005-04-16 1066 * at the bottom level available, and propagating the changes upward ^1da177e4c3f41 Linus Torvalds 2005-04-16 1067 * as necessary, plus some accounting needed to play nicely with other ^1da177e4c3f41 Linus Torvalds 2005-04-16 1068 * parts of the VM system. ^1da177e4c3f41 Linus Torvalds 2005-04-16 1069 * At each level, we keep a list of pages, which are heads of continuous 6e292b9be7f435 Matthew Wilcox 2018-06-07 1070 * free pages of length of (1 << order) and marked with PageBuddy. 6e292b9be7f435 Matthew Wilcox 2018-06-07 1071 * Page's order is recorded in page_private(page) field. ^1da177e4c3f41 Linus Torvalds 2005-04-16 1072 * So when we are allocating or freeing one, we can derive the state of the ^1da177e4c3f41 Linus Torvalds 2005-04-16 1073 * other. That is, if we allocate a small block, and both were ^1da177e4c3f41 Linus Torvalds 2005-04-16 1074 * free, the remainder of the region must be split into blocks. ^1da177e4c3f41 Linus Torvalds 2005-04-16 1075 * If a block is freed, and its buddy is also free, then this ^1da177e4c3f41 Linus Torvalds 2005-04-16 1076 * triggers coalescing into a block of larger size. ^1da177e4c3f41 Linus Torvalds 2005-04-16 1077 * 6d49e352ae9aed Nadia Yvette Chambers 2012-12-06 1078 * -- nyc ^1da177e4c3f41 Linus Torvalds 2005-04-16 1079 */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 1080 48db57f8ff10eb Nicholas Piggin 2006-01-08 1081 static inline void __free_one_page(struct page *page, dc4b0caff24d9b Mel Gorman 2014-06-04 1082 unsigned long pfn, ed0ae21dc5fe3b Mel Gorman 2009-06-16 1083 struct zone *zone, unsigned int order, f04a5d5d913fa8 David Hildenbrand 2020-10-15 1084 int migratetype, fpi_t fpi_flags) ^1da177e4c3f41 Linus Torvalds 2005-04-16 1085 { a2129f24798a99 Alexander Duyck 2020-04-06 1086 struct capture_control *capc = task_capc(zone); b3d40a2b6d10c9 David Hildenbrand 2022-03-22 1087 unsigned int max_order = pageblock_order; 3f649ab728cda8 Kees Cook 2020-06-03 1088 unsigned long buddy_pfn; a2129f24798a99 Alexander Duyck 2020-04-06 1089 unsigned long combined_pfn; a2129f24798a99 Alexander Duyck 2020-04-06 1090 struct page *buddy; a2129f24798a99 Alexander Duyck 2020-04-06 1091 bool to_tail; 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1092 bool page_needs_acceptance; d9dddbf556674b Vlastimil Babka 2016-03-25 1093 d29bb9782d2206 Cody P Schafer 2013-02-22 1094 VM_BUG_ON(!zone_is_initialized(zone)); 6e9f0d582dde09 Kirill A. Shutemov 2015-02-11 1095 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1096 ed0ae21dc5fe3b Mel Gorman 2009-06-16 1097 VM_BUG_ON(migratetype == -1); d9dddbf556674b Vlastimil Babka 2016-03-25 1098 if (likely(!is_migrate_isolate(migratetype))) 8f82b55dd558a7 Joonsoo Kim 2014-11-13 1099 __mod_zone_freepage_state(zone, 1 << order, migratetype); ed0ae21dc5fe3b Mel Gorman 2009-06-16 1100 76741e776a3797 Vlastimil Babka 2017-02-22 1101 VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page); 309381feaee564 Sasha Levin 2014-01-23 1102 VM_BUG_ON_PAGE(bad_range(zone, page), page); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1103 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1104 if (PageUnaccepted(page)) { 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1105 page_needs_acceptance = true; 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1106 __ClearPageUnaccepted(page); 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1107 } 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1108 d9dddbf556674b Vlastimil Babka 2016-03-25 1109 continue_merging: 7ad69832f37e3c Muchun Song 2020-12-14 1110 while (order < max_order) { 5e1f0f098b4649 Mel Gorman 2019-03-05 1111 if (compaction_capture(capc, page, order, migratetype)) { 5e1f0f098b4649 Mel Gorman 2019-03-05 1112 __mod_zone_freepage_state(zone, -(1 << order), 5e1f0f098b4649 Mel Gorman 2019-03-05 1113 migratetype); 5e1f0f098b4649 Mel Gorman 2019-03-05 1114 return; 5e1f0f098b4649 Mel Gorman 2019-03-05 1115 } 76741e776a3797 Vlastimil Babka 2017-02-22 1116 buddy_pfn = __find_buddy_pfn(pfn, order); 76741e776a3797 Vlastimil Babka 2017-02-22 1117 buddy = page + (buddy_pfn - pfn); 13ad59df67f197 Vlastimil Babka 2017-02-22 1118 cb2b95e1c6b56e Andy Whitcroft 2006-06-23 1119 if (!page_is_buddy(page, buddy, order)) d9dddbf556674b Vlastimil Babka 2016-03-25 1120 goto done_merging; c0a32fc5a2e470 Stanislaw Gruszka 2012-01-10 1121 /* c0a32fc5a2e470 Stanislaw Gruszka 2012-01-10 1122 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page, c0a32fc5a2e470 Stanislaw Gruszka 2012-01-10 1123 * merge with it and move up one order. c0a32fc5a2e470 Stanislaw Gruszka 2012-01-10 1124 */ b03641af680959 Dan Williams 2019-05-14 1125 if (page_is_guard(buddy)) 2847cf95c68fa5 Joonsoo Kim 2014-12-12 1126 clear_page_guard(zone, buddy, order, migratetype); b03641af680959 Dan Williams 2019-05-14 1127 else 6ab0136310961e Alexander Duyck 2020-04-06 1128 del_page_from_free_list(buddy, zone, order); 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1129 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1130 /* Mark page unaccepted if any of merged pages were unaccepted */ 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1131 if (PageUnaccepted(buddy)) { 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1132 page_needs_acceptance = true; 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1133 __ClearPageUnaccepted(buddy); 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1134 } 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1135 76741e776a3797 Vlastimil Babka 2017-02-22 1136 combined_pfn = buddy_pfn & pfn; 76741e776a3797 Vlastimil Babka 2017-02-22 1137 page = page + (combined_pfn - pfn); 76741e776a3797 Vlastimil Babka 2017-02-22 1138 pfn = combined_pfn; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1139 order++; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1140 } 7ad69832f37e3c Muchun Song 2020-12-14 1141 if (order < MAX_ORDER - 1) { d9dddbf556674b Vlastimil Babka 2016-03-25 1142 /* If we are here, it means order is >= pageblock_order. 1dd214b8f21ca4 Zi Yan 2022-03-22 1143 * We want to prevent merge between freepages on pageblock 1dd214b8f21ca4 Zi Yan 2022-03-22 1144 * without fallbacks and normal pageblock. Without this, 1dd214b8f21ca4 Zi Yan 2022-03-22 1145 * pageblock isolation could cause incorrect freepage or CMA 1dd214b8f21ca4 Zi Yan 2022-03-22 1146 * accounting or HIGHATOMIC accounting. d9dddbf556674b Vlastimil Babka 2016-03-25 1147 * d9dddbf556674b Vlastimil Babka 2016-03-25 1148 * We don't want to hit this code for the more frequent d9dddbf556674b Vlastimil Babka 2016-03-25 1149 * low-order merging. d9dddbf556674b Vlastimil Babka 2016-03-25 1150 */ d9dddbf556674b Vlastimil Babka 2016-03-25 1151 int buddy_mt; d9dddbf556674b Vlastimil Babka 2016-03-25 1152 76741e776a3797 Vlastimil Babka 2017-02-22 1153 buddy_pfn = __find_buddy_pfn(pfn, order); 76741e776a3797 Vlastimil Babka 2017-02-22 1154 buddy = page + (buddy_pfn - pfn); 787af64d05cd52 Zi Yan 2022-03-30 1155 787af64d05cd52 Zi Yan 2022-03-30 1156 if (!page_is_buddy(page, buddy, order)) 787af64d05cd52 Zi Yan 2022-03-30 1157 goto done_merging; d9dddbf556674b Vlastimil Babka 2016-03-25 1158 buddy_mt = get_pageblock_migratetype(buddy); d9dddbf556674b Vlastimil Babka 2016-03-25 1159 d9dddbf556674b Vlastimil Babka 2016-03-25 1160 if (migratetype != buddy_mt 1dd214b8f21ca4 Zi Yan 2022-03-22 1161 && (!migratetype_is_mergeable(migratetype) || 1dd214b8f21ca4 Zi Yan 2022-03-22 1162 !migratetype_is_mergeable(buddy_mt))) d9dddbf556674b Vlastimil Babka 2016-03-25 1163 goto done_merging; 7ad69832f37e3c Muchun Song 2020-12-14 1164 max_order = order + 1; d9dddbf556674b Vlastimil Babka 2016-03-25 1165 goto continue_merging; d9dddbf556674b Vlastimil Babka 2016-03-25 1166 } d9dddbf556674b Vlastimil Babka 2016-03-25 1167 d9dddbf556674b Vlastimil Babka 2016-03-25 1168 done_merging: ab130f9108dcf2 Matthew Wilcox (Oracle 2020-10-15 1169) set_buddy_order(page, order); 6dda9d55bf5450 Corrado Zoccolo 2010-05-24 1170 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1171 /* 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1172 * The page gets marked as PageUnaccepted() if any of merged-in pages 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1173 * is PageUnaccepted(). 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1174 * 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1175 * New pages, just being added to buddy allocator, do not have 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1176 * PageUnaccepted() set. FPI_UNACCEPTED_SLOWPATH indicates that the 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1177 * page is new and page_is_unaccepted() check is required to 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1178 * determinate if acceptance is required. 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1179 * 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1180 * Avoid calling page_is_unaccepted() if it is known that the page 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1181 * needs acceptance. It can be costly. 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1182 */ 0845556ccd9555 Kirill A. Shutemov 2021-08-25 @1183 if (!page_needs_acceptance && (fpi_flags & FPI_UNACCEPTED_SLOWPATH)) 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1184 page_needs_acceptance = page_is_unaccepted(page, order); 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1185 if (page_needs_acceptance) 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1186 __SetPageUnaccepted(page); 0845556ccd9555 Kirill A. Shutemov 2021-08-25 1187 47b6a24a23825a David Hildenbrand 2020-10-15 1188 if (fpi_flags & FPI_TO_TAIL) 47b6a24a23825a David Hildenbrand 2020-10-15 1189 to_tail = true; 47b6a24a23825a David Hildenbrand 2020-10-15 1190 else if (is_shuffle_order(order)) a2129f24798a99 Alexander Duyck 2020-04-06 1191 to_tail = shuffle_pick_tail(); 97500a4a54876d Dan Williams 2019-05-14 1192 else a2129f24798a99 Alexander Duyck 2020-04-06 1193 to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order); 97500a4a54876d Dan Williams 2019-05-14 1194 a2129f24798a99 Alexander Duyck 2020-04-06 1195 if (to_tail) 6ab0136310961e Alexander Duyck 2020-04-06 1196 add_to_free_list_tail(page, zone, order, migratetype); a2129f24798a99 Alexander Duyck 2020-04-06 1197 else 6ab0136310961e Alexander Duyck 2020-04-06 1198 add_to_free_list(page, zone, order, migratetype); 36e66c554b5c6a Alexander Duyck 2020-04-06 1199 36e66c554b5c6a Alexander Duyck 2020-04-06 1200 /* Notify page reporting subsystem of freed page */ f04a5d5d913fa8 David Hildenbrand 2020-10-15 1201 if (!(fpi_flags & FPI_SKIP_REPORT_NOTIFY)) 36e66c554b5c6a Alexander Duyck 2020-04-06 1202 page_reporting_notify_free(order); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1203 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 1204 -- 0-DAY CI Kernel Test Service https://01.org/lkp _______________________________________________ kbuild mailing list -- kbuild@lists.01.org To unsubscribe send an email to kbuild-le...@lists.01.org
