Hi Donet, kernel test robot noticed the following build errors: [auto build test ERROR on akpm-mm/mm-everything] url: https://github.com/intel-lab-lkp/linux/commits/Donet-Tom/mm-migration-shared-anonymous-migration-test-is-failing/20241219-204920 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/20241219124717.4907-1-donettom%40linux.ibm.com patch subject: [PATCH] mm: migration :shared anonymous migration test is failing config: arc-randconfig-002-20241220 (https://download.01.org/0day-ci/archive/20241220/202412201738.gUNPwJ1x-lkp@xxxxxxxxx/config) compiler: arc-elf-gcc (GCC) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241220/202412201738.gUNPwJ1x-lkp@xxxxxxxxx/reproduce) 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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202412201738.gUNPwJ1x-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): In file included from include/linux/migrate.h:8, from mm/rmap.c:69: include/linux/hugetlb.h:1063:5: warning: no previous prototype for 'replace_free_hugepage_folios' [-Wmissing-prototypes] 1063 | int replace_free_hugepage_folios(unsigned long start_pfn, unsigned long end_pfn) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/rmap.c: In function 'try_to_migrate_one': >> mm/rmap.c:2157:34: error: implicit declaration of function 'huge_ptep_get_and_clear'; did you mean 'ptep_get_and_clear'? [-Werror=implicit-function-declaration] 2157 | pteval = huge_ptep_get_and_clear(mm, address, pvmw.pte); | ^~~~~~~~~~~~~~~~~~~~~~~ | ptep_get_and_clear >> mm/rmap.c:2157:34: error: incompatible types when assigning to type 'pte_t' from type 'int' >> mm/rmap.c:2326:33: error: implicit declaration of function 'flush_hugetlb_page'; did you mean 'flush_tlb_page'? [-Werror=implicit-function-declaration] 2326 | flush_hugetlb_page(vma, address); | ^~~~~~~~~~~~~~~~~~ | flush_tlb_page cc1: some warnings being treated as errors vim +2157 mm/rmap.c 2081 2082 /* Unexpected PMD-mapped THP? */ 2083 VM_BUG_ON_FOLIO(!pvmw.pte, folio); 2084 2085 pfn = pte_pfn(ptep_get(pvmw.pte)); 2086 2087 if (folio_is_zone_device(folio)) { 2088 /* 2089 * Our PTE is a non-present device exclusive entry and 2090 * calculating the subpage as for the common case would 2091 * result in an invalid pointer. 2092 * 2093 * Since only PAGE_SIZE pages can currently be 2094 * migrated, just set it to page. This will need to be 2095 * changed when hugepage migrations to device private 2096 * memory are supported. 2097 */ 2098 VM_BUG_ON_FOLIO(folio_nr_pages(folio) > 1, folio); 2099 subpage = &folio->page; 2100 } else { 2101 subpage = folio_page(folio, pfn - folio_pfn(folio)); 2102 } 2103 address = pvmw.address; 2104 anon_exclusive = folio_test_anon(folio) && 2105 PageAnonExclusive(subpage); 2106 2107 if (folio_test_hugetlb(folio)) { 2108 bool anon = folio_test_anon(folio); 2109 2110 /* 2111 * huge_pmd_unshare may unmap an entire PMD page. 2112 * There is no way of knowing exactly which PMDs may 2113 * be cached for this mm, so we must flush them all. 2114 * start/end were already adjusted above to cover this 2115 * range. 2116 */ 2117 flush_cache_range(vma, range.start, range.end); 2118 2119 /* 2120 * To call huge_pmd_unshare, i_mmap_rwsem must be 2121 * held in write mode. Caller needs to explicitly 2122 * do this outside rmap routines. 2123 * 2124 * We also must hold hugetlb vma_lock in write mode. 2125 * Lock order dictates acquiring vma_lock BEFORE 2126 * i_mmap_rwsem. We can only try lock here and 2127 * fail if unsuccessful. 2128 */ 2129 if (!anon) { 2130 VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); 2131 if (!hugetlb_vma_trylock_write(vma)) { 2132 page_vma_mapped_walk_done(&pvmw); 2133 ret = false; 2134 break; 2135 } 2136 if (huge_pmd_unshare(mm, vma, address, pvmw.pte)) { 2137 hugetlb_vma_unlock_write(vma); 2138 flush_tlb_range(vma, 2139 range.start, range.end); 2140 2141 /* 2142 * The ref count of the PMD page was 2143 * dropped which is part of the way map 2144 * counting is done for shared PMDs. 2145 * Return 'true' here. When there is 2146 * no other sharing, huge_pmd_unshare 2147 * returns false and we will unmap the 2148 * actual page and drop map count 2149 * to zero. 2150 */ 2151 page_vma_mapped_walk_done(&pvmw); 2152 break; 2153 } 2154 hugetlb_vma_unlock_write(vma); 2155 } 2156 /* Nuke the hugetlb page table entry */ > 2157 pteval = huge_ptep_get_and_clear(mm, address, pvmw.pte); 2158 } else { 2159 flush_cache_page(vma, address, pfn); 2160 /* Nuke the page table entry. */ 2161 if (should_defer_flush(mm, flags)) { 2162 /* 2163 * We clear the PTE but do not flush so potentially 2164 * a remote CPU could still be writing to the folio. 2165 * If the entry was previously clean then the 2166 * architecture must guarantee that a clear->dirty 2167 * transition on a cached TLB entry is written through 2168 * and traps if the PTE is unmapped. 2169 */ 2170 pteval = ptep_get_and_clear(mm, address, pvmw.pte); 2171 2172 set_tlb_ubc_flush_pending(mm, pteval, address); 2173 } else { 2174 pteval = ptep_get_and_clear(mm, address, pvmw.pte); 2175 } 2176 } 2177 2178 /* Set the dirty flag on the folio now the pte is gone. */ 2179 if (pte_dirty(pteval)) 2180 folio_mark_dirty(folio); 2181 2182 /* Update high watermark before we lower rss */ 2183 update_hiwater_rss(mm); 2184 2185 if (folio_is_device_private(folio)) { 2186 unsigned long pfn = folio_pfn(folio); 2187 swp_entry_t entry; 2188 pte_t swp_pte; 2189 2190 if (anon_exclusive) 2191 WARN_ON_ONCE(folio_try_share_anon_rmap_pte(folio, 2192 subpage)); 2193 2194 /* 2195 * Store the pfn of the page in a special migration 2196 * pte. do_swap_page() will wait until the migration 2197 * pte is removed and then restart fault handling. 2198 */ 2199 entry = pte_to_swp_entry(pteval); 2200 if (is_writable_device_private_entry(entry)) 2201 entry = make_writable_migration_entry(pfn); 2202 else if (anon_exclusive) 2203 entry = make_readable_exclusive_migration_entry(pfn); 2204 else 2205 entry = make_readable_migration_entry(pfn); 2206 swp_pte = swp_entry_to_pte(entry); 2207 2208 /* 2209 * pteval maps a zone device page and is therefore 2210 * a swap pte. 2211 */ 2212 if (pte_swp_soft_dirty(pteval)) 2213 swp_pte = pte_swp_mksoft_dirty(swp_pte); 2214 if (pte_swp_uffd_wp(pteval)) 2215 swp_pte = pte_swp_mkuffd_wp(swp_pte); 2216 set_pte_at(mm, pvmw.address, pvmw.pte, swp_pte); 2217 trace_set_migration_pte(pvmw.address, pte_val(swp_pte), 2218 folio_order(folio)); 2219 /* 2220 * No need to invalidate here it will synchronize on 2221 * against the special swap migration pte. 2222 */ 2223 } else if (PageHWPoison(subpage)) { 2224 pteval = swp_entry_to_pte(make_hwpoison_entry(subpage)); 2225 if (folio_test_hugetlb(folio)) { 2226 hugetlb_count_sub(folio_nr_pages(folio), mm); 2227 set_huge_pte_at(mm, address, pvmw.pte, pteval, 2228 hsz); 2229 } else { 2230 dec_mm_counter(mm, mm_counter(folio)); 2231 set_pte_at(mm, address, pvmw.pte, pteval); 2232 } 2233 2234 } else if (pte_unused(pteval) && !userfaultfd_armed(vma)) { 2235 /* 2236 * The guest indicated that the page content is of no 2237 * interest anymore. Simply discard the pte, vmscan 2238 * will take care of the rest. 2239 * A future reference will then fault in a new zero 2240 * page. When userfaultfd is active, we must not drop 2241 * this page though, as its main user (postcopy 2242 * migration) will not expect userfaults on already 2243 * copied pages. 2244 */ 2245 dec_mm_counter(mm, mm_counter(folio)); 2246 } else { 2247 swp_entry_t entry; 2248 pte_t swp_pte; 2249 2250 if (arch_unmap_one(mm, vma, address, pteval) < 0) { 2251 if (folio_test_hugetlb(folio)) 2252 set_huge_pte_at(mm, address, pvmw.pte, 2253 pteval, hsz); 2254 else 2255 set_pte_at(mm, address, pvmw.pte, pteval); 2256 ret = false; 2257 page_vma_mapped_walk_done(&pvmw); 2258 break; 2259 } 2260 VM_BUG_ON_PAGE(pte_write(pteval) && folio_test_anon(folio) && 2261 !anon_exclusive, subpage); 2262 2263 /* See folio_try_share_anon_rmap_pte(): clear PTE first. */ 2264 if (folio_test_hugetlb(folio)) { 2265 if (anon_exclusive && 2266 hugetlb_try_share_anon_rmap(folio)) { 2267 set_huge_pte_at(mm, address, pvmw.pte, 2268 pteval, hsz); 2269 ret = false; 2270 page_vma_mapped_walk_done(&pvmw); 2271 break; 2272 } 2273 } else if (anon_exclusive && 2274 folio_try_share_anon_rmap_pte(folio, subpage)) { 2275 set_pte_at(mm, address, pvmw.pte, pteval); 2276 ret = false; 2277 page_vma_mapped_walk_done(&pvmw); 2278 break; 2279 } 2280 2281 /* 2282 * Store the pfn of the page in a special migration 2283 * pte. do_swap_page() will wait until the migration 2284 * pte is removed and then restart fault handling. 2285 */ 2286 if (pte_write(pteval)) 2287 entry = make_writable_migration_entry( 2288 page_to_pfn(subpage)); 2289 else if (anon_exclusive) 2290 entry = make_readable_exclusive_migration_entry( 2291 page_to_pfn(subpage)); 2292 else 2293 entry = make_readable_migration_entry( 2294 page_to_pfn(subpage)); 2295 if (pte_young(pteval)) 2296 entry = make_migration_entry_young(entry); 2297 if (pte_dirty(pteval)) 2298 entry = make_migration_entry_dirty(entry); 2299 swp_pte = swp_entry_to_pte(entry); 2300 if (pte_soft_dirty(pteval)) 2301 swp_pte = pte_swp_mksoft_dirty(swp_pte); 2302 if (pte_uffd_wp(pteval)) 2303 swp_pte = pte_swp_mkuffd_wp(swp_pte); 2304 if (folio_test_hugetlb(folio)) 2305 set_huge_pte_at(mm, address, pvmw.pte, swp_pte, 2306 hsz); 2307 else 2308 set_pte_at(mm, address, pvmw.pte, swp_pte); 2309 trace_set_migration_pte(address, pte_val(swp_pte), 2310 folio_order(folio)); 2311 /* 2312 * No need to invalidate here it will synchronize on 2313 * against the special swap migration pte. 2314 */ 2315 } 2316 2317 if (unlikely(folio_test_hugetlb(folio))) 2318 hugetlb_remove_rmap(folio); 2319 else 2320 folio_remove_rmap_pte(folio, subpage, vma); 2321 if (vma->vm_flags & VM_LOCKED) 2322 mlock_drain_local(); 2323 2324 if (!should_defer_flush(mm, flags)) { 2325 if (folio_test_hugetlb(folio)) > 2326 flush_hugetlb_page(vma, address); 2327 else 2328 flush_tlb_page(vma, address); 2329 } 2330 2331 folio_put(folio); 2332 } 2333 2334 mmu_notifier_invalidate_range_end(&range); 2335 2336 return ret; 2337 } 2338 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki