Hi Muchun, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on mmotm/master] url: https://github.com/0day-ci/linux/commits/Muchun-Song/mm-slab-Add-a-__GFP_... base: git://git.cmpxchg.org/linux-mmotm.git master config: xtensa-allyesconfig (attached as .config) compiler: xtensa-linux-gcc (GCC) 9.3.0 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 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=xtensa If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): In file included from include/linux/kernel.h:11, from include/linux/interrupt.h:6, from mm/kasan/common.c:18: include/linux/scatterlist.h: In function 'sg_set_buf': arch/xtensa/include/asm/page.h:182:9: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] 182 | ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) | ^~ include/linux/compiler.h:78:42: note: in definition of macro 'unlikely' 78 | # define unlikely(x) __builtin_expect(!!(x), 0) | ^ include/linux/scatterlist.h:143:2: note: in expansion of macro 'BUG_ON' 143 | BUG_ON(!virt_addr_valid(buf)); | ^~~~~~ arch/xtensa/include/asm/page.h:190:32: note: in expansion of macro 'pfn_valid' 190 | #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) | ^~~~~~~~~ include/linux/scatterlist.h:143:10: note: in expansion of macro 'virt_addr_valid' 143 | BUG_ON(!virt_addr_valid(buf)); | ^~~~~~~~~~~~~~~ In file included from include/linux/mm_types_task.h:16, from include/linux/mm_types.h:5, from include/linux/mmzone.h:21, from include/linux/topology.h:33, from include/linux/irq.h:19, from include/asm-generic/hardirq.h:13, from ./arch/xtensa/include/generated/asm/hardirq.h:1, from include/linux/hardirq.h:9, from include/linux/interrupt.h:11, from mm/kasan/common.c:18: mm/kasan/../internal.h: In function 'mem_map_next': arch/xtensa/include/asm/page.h:182:9: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] 182 | ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) | ^~ 393 | if (!pfn_valid(pfn)) | ^~~~~~~~~ -- In file included from arch/xtensa/include/asm/processor.h:15, from arch/xtensa/include/asm/bitops.h:20, from include/linux/bitops.h:19, from mm/kasan/report.c:17: include/linux/scatterlist.h: In function 'sg_set_buf': arch/xtensa/include/asm/page.h:182:9: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] 182 | ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) | ^~ include/linux/compiler.h:78:42: note: in definition of macro 'unlikely' 78 | # define unlikely(x) __builtin_expect(!!(x), 0) | ^ include/linux/scatterlist.h:143:2: note: in expansion of macro 'BUG_ON' 143 | BUG_ON(!virt_addr_valid(buf)); | ^~~~~~ arch/xtensa/include/asm/page.h:190:32: note: in expansion of macro 'pfn_valid' 190 | #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) | ^~~~~~~~~ include/linux/scatterlist.h:143:10: note: in expansion of macro 'virt_addr_valid' 143 | BUG_ON(!virt_addr_valid(buf)); | ^~~~~~~~~~~~~~~ In file included from include/linux/mm_types_task.h:16, from include/linux/mm_types.h:5, from include/linux/mmzone.h:21, from include/linux/gfp.h:6, from include/linux/mm.h:10, from include/linux/kallsyms.h:12, from include/linux/ftrace.h:11, from mm/kasan/report.c:18: mm/kasan/../internal.h: In function 'mem_map_next': arch/xtensa/include/asm/page.h:182:9: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] 182 | ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) | ^~ 393 | if (!pfn_valid(pfn)) | ^~~~~~~~~ mm/kasan/report.c: At top level: mm/kasan/report.c:474:6: warning: no previous prototype for '__kasan_report' [-Wmissing-prototypes] 474 | void __kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip) | ^~~~~~~~~~~~~~ -- In file included from arch/xtensa/include/asm/processor.h:15, from arch/xtensa/include/asm/bitops.h:20, from include/linux/bitops.h:19, from mm/kasan/generic_report.c:17: include/linux/scatterlist.h: In function 'sg_set_buf': arch/xtensa/include/asm/page.h:182:9: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] 182 | ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) | ^~ include/linux/compiler.h:78:42: note: in definition of macro 'unlikely' 78 | # define unlikely(x) __builtin_expect(!!(x), 0) | ^ include/linux/scatterlist.h:143:2: note: in expansion of macro 'BUG_ON' 143 | BUG_ON(!virt_addr_valid(buf)); | ^~~~~~ arch/xtensa/include/asm/page.h:190:32: note: in expansion of macro 'pfn_valid' 190 | #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) | ^~~~~~~~~ include/linux/scatterlist.h:143:10: note: in expansion of macro 'virt_addr_valid' 143 | BUG_ON(!virt_addr_valid(buf)); | ^~~~~~~~~~~~~~~ In file included from include/linux/mm_types_task.h:16, from include/linux/mm_types.h:5, from include/linux/mmzone.h:21, from include/linux/gfp.h:6, from include/linux/mm.h:10, from include/linux/kallsyms.h:12, from include/linux/ftrace.h:11, from mm/kasan/generic_report.c:18: mm/kasan/../internal.h: In function 'mem_map_next': arch/xtensa/include/asm/page.h:182:9: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] 182 | ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) | ^~ 393 | if (!pfn_valid(pfn)) | ^~~~~~~~~ mm/kasan/generic_report.c: At top level: mm/kasan/generic_report.c:116:6: warning: no previous prototype for '__asan_report_load1_noabort' [-Wmissing-prototypes] 116 | void __asan_report_load##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:129:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_LOAD' 129 | DEFINE_ASAN_REPORT_LOAD(1); | ^~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:116:6: warning: no previous prototype for '__asan_report_load2_noabort' [-Wmissing-prototypes] 116 | void __asan_report_load##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:130:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_LOAD' 130 | DEFINE_ASAN_REPORT_LOAD(2); | ^~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:116:6: warning: no previous prototype for '__asan_report_load4_noabort' [-Wmissing-prototypes] 116 | void __asan_report_load##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:131:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_LOAD' 131 | DEFINE_ASAN_REPORT_LOAD(4); | ^~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:116:6: warning: no previous prototype for '__asan_report_load8_noabort' [-Wmissing-prototypes] 116 | void __asan_report_load##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:132:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_LOAD' 132 | DEFINE_ASAN_REPORT_LOAD(8); | ^~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:116:6: warning: no previous prototype for '__asan_report_load16_noabort' [-Wmissing-prototypes] 116 | void __asan_report_load##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:133:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_LOAD' 133 | DEFINE_ASAN_REPORT_LOAD(16); | ^~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:123:6: warning: no previous prototype for '__asan_report_store1_noabort' [-Wmissing-prototypes] 123 | void __asan_report_store##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:134:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_STORE' 134 | DEFINE_ASAN_REPORT_STORE(1); | ^~~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:123:6: warning: no previous prototype for '__asan_report_store2_noabort' [-Wmissing-prototypes] 123 | void __asan_report_store##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:135:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_STORE' 135 | DEFINE_ASAN_REPORT_STORE(2); | ^~~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:123:6: warning: no previous prototype for '__asan_report_store4_noabort' [-Wmissing-prototypes] 123 | void __asan_report_store##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:136:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_STORE' 136 | DEFINE_ASAN_REPORT_STORE(4); | ^~~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:123:6: warning: no previous prototype for '__asan_report_store8_noabort' [-Wmissing-prototypes] 123 | void __asan_report_store##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:137:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_STORE' 137 | DEFINE_ASAN_REPORT_STORE(8); | ^~~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:123:6: warning: no previous prototype for '__asan_report_store16_noabort' [-Wmissing-prototypes] 123 | void __asan_report_store##size##_noabort(unsigned long addr) | ^~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:138:1: note: in expansion of macro 'DEFINE_ASAN_REPORT_STORE' 138 | DEFINE_ASAN_REPORT_STORE(16); | ^~~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:140:6: warning: no previous prototype for '__asan_report_load_n_noabort' [-Wmissing-prototypes] 140 | void __asan_report_load_n_noabort(unsigned long addr, size_t size) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/generic_report.c:146:6: warning: no previous prototype for '__asan_report_store_n_noabort' [-Wmissing-prototypes] 146 | void __asan_report_store_n_noabort(unsigned long addr, size_t size) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +/pfn_valid +393 mm/kasan/../internal.h 69d177c2fc702d Andy Whitcroft 2008-11-06 383 69d177c2fc702d Andy Whitcroft 2008-11-06 384 /* 25985edcedea63 Lucas De Marchi 2011-03-30 385 * Iterator over all subpages within the maximally aligned gigantic 69d177c2fc702d Andy Whitcroft 2008-11-06 386 * page 'base'. Handle any discontiguity in the mem_map. 69d177c2fc702d Andy Whitcroft 2008-11-06 387 */ 69d177c2fc702d Andy Whitcroft 2008-11-06 388 static inline struct page *mem_map_next(struct page *iter, 69d177c2fc702d Andy Whitcroft 2008-11-06 389 struct page *base, int offset) 69d177c2fc702d Andy Whitcroft 2008-11-06 390 { 69d177c2fc702d Andy Whitcroft 2008-11-06 391 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { 69d177c2fc702d Andy Whitcroft 2008-11-06 392 unsigned long pfn = page_to_pfn(base) + offset; 69d177c2fc702d Andy Whitcroft 2008-11-06 @393 if (!pfn_valid(pfn)) 69d177c2fc702d Andy Whitcroft 2008-11-06 394 return NULL; 69d177c2fc702d Andy Whitcroft 2008-11-06 395 return pfn_to_page(pfn); 69d177c2fc702d Andy Whitcroft 2008-11-06 396 } 69d177c2fc702d Andy Whitcroft 2008-11-06 397 return iter + 1; 69d177c2fc702d Andy Whitcroft 2008-11-06 398 } 69d177c2fc702d Andy Whitcroft 2008-11-06 399 :::::: The code at line 393 was first introduced by commit :::::: 69d177c2fc702d402b17fdca2190d5a7e3ca55c5 hugetlbfs: handle pages higher order than MAX_ORDER :::::: TO: Andy Whitcroft <apw(a)shadowen.org&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org