Hi Doug, I love your patch! Perhaps something to improve: [auto build test WARNING on robh/for-next] [also build test WARNING on linus/master v6.0-rc5] [cannot apply to akpm-mm/mm-everything next-20220914] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Doug-Berger/mm-introduce-Designated-Movable-Blocks/20220914-040216 base: https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next config: i386-randconfig-a002 (https://download.01.org/0day-ci/archive/20220915/202209150009.PoWlLoNu-lkp@xxxxxxxxx/config) compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/635e919c92ca242c4b900bdfc7e21529e76f2f8e git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Doug-Berger/mm-introduce-Designated-Movable-Blocks/20220914-040216 git checkout 635e919c92ca242c4b900bdfc7e21529e76f2f8e # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> mm/page_alloc.c:9236:5: warning: no previous prototype for function '_alloc_contig_range' [-Wmissing-prototypes] int _alloc_contig_range(unsigned long start, unsigned long end, ^ mm/page_alloc.c:9236:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int _alloc_contig_range(unsigned long start, unsigned long end, ^ static 1 warning generated. vim +/_alloc_contig_range +9236 mm/page_alloc.c 9235 > 9236 int _alloc_contig_range(unsigned long start, unsigned long end, 9237 unsigned int migratetype, gfp_t gfp_mask) 9238 { 9239 unsigned long outer_start, outer_end; 9240 int order; 9241 int ret = 0; 9242 9243 struct compact_control cc = { 9244 .nr_migratepages = 0, 9245 .order = -1, 9246 .zone = page_zone(pfn_to_page(start)), 9247 .mode = MIGRATE_SYNC, 9248 .ignore_skip_hint = true, 9249 .no_set_skip_hint = true, 9250 .gfp_mask = current_gfp_context(gfp_mask), 9251 .alloc_contig = true, 9252 }; 9253 INIT_LIST_HEAD(&cc.migratepages); 9254 9255 /* 9256 * What we do here is we mark all pageblocks in range as 9257 * MIGRATE_ISOLATE. Because pageblock and max order pages may 9258 * have different sizes, and due to the way page allocator 9259 * work, start_isolate_page_range() has special handlings for this. 9260 * 9261 * Once the pageblocks are marked as MIGRATE_ISOLATE, we 9262 * migrate the pages from an unaligned range (ie. pages that 9263 * we are interested in). This will put all the pages in 9264 * range back to page allocator as MIGRATE_ISOLATE. 9265 * 9266 * When this is done, we take the pages in range from page 9267 * allocator removing them from the buddy system. This way 9268 * page allocator will never consider using them. 9269 * 9270 * This lets us mark the pageblocks back as 9271 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the 9272 * aligned range but not in the unaligned, original range are 9273 * put back to page allocator so that buddy can use them. 9274 */ 9275 9276 ret = start_isolate_page_range(start, end, migratetype, 0, gfp_mask); 9277 if (ret) 9278 goto done; 9279 9280 drain_all_pages(cc.zone); 9281 9282 /* 9283 * In case of -EBUSY, we'd like to know which page causes problem. 9284 * So, just fall through. test_pages_isolated() has a tracepoint 9285 * which will report the busy page. 9286 * 9287 * It is possible that busy pages could become available before 9288 * the call to test_pages_isolated, and the range will actually be 9289 * allocated. So, if we fall through be sure to clear ret so that 9290 * -EBUSY is not accidentally used or returned to caller. 9291 */ 9292 ret = __alloc_contig_migrate_range(&cc, start, end); 9293 if (ret && ret != -EBUSY) 9294 goto done; 9295 ret = 0; 9296 sync_hugetlb_dissolve(); 9297 9298 /* 9299 * Pages from [start, end) are within a pageblock_nr_pages 9300 * aligned blocks that are marked as MIGRATE_ISOLATE. What's 9301 * more, all pages in [start, end) are free in page allocator. 9302 * What we are going to do is to allocate all pages from 9303 * [start, end) (that is remove them from page allocator). 9304 * 9305 * The only problem is that pages at the beginning and at the 9306 * end of interesting range may be not aligned with pages that 9307 * page allocator holds, ie. they can be part of higher order 9308 * pages. Because of this, we reserve the bigger range and 9309 * once this is done free the pages we are not interested in. 9310 * 9311 * We don't have to hold zone->lock here because the pages are 9312 * isolated thus they won't get removed from buddy. 9313 */ 9314 9315 order = 0; 9316 outer_start = start; 9317 while (!PageBuddy(pfn_to_page(outer_start))) { 9318 if (++order >= MAX_ORDER) { 9319 outer_start = start; 9320 break; 9321 } 9322 outer_start &= ~0UL << order; 9323 } 9324 9325 if (outer_start != start) { 9326 order = buddy_order(pfn_to_page(outer_start)); 9327 9328 /* 9329 * outer_start page could be small order buddy page and 9330 * it doesn't include start page. Adjust outer_start 9331 * in this case to report failed page properly 9332 * on tracepoint in test_pages_isolated() 9333 */ 9334 if (outer_start + (1UL << order) <= start) 9335 outer_start = start; 9336 } 9337 9338 /* Make sure the range is really isolated. */ 9339 if (test_pages_isolated(outer_start, end, 0)) { 9340 ret = -EBUSY; 9341 goto done; 9342 } 9343 9344 /* Grab isolated pages from freelists. */ 9345 outer_end = isolate_freepages_range(&cc, outer_start, end); 9346 if (!outer_end) { 9347 ret = -EBUSY; 9348 goto done; 9349 } 9350 9351 /* Free head and tail (if any) */ 9352 if (start != outer_start) 9353 free_contig_range(outer_start, start - outer_start); 9354 if (end != outer_end) 9355 free_contig_range(end, outer_end - end); 9356 9357 done: 9358 undo_isolate_page_range(start, end, migratetype); 9359 return ret; 9360 } 9361 -- 0-DAY CI Kernel Test Service https://01.org/lkp
