Hi "Aneesh, I love your patch! Perhaps something to improve: [auto build test WARNING on powerpc/next] [also build test WARNING on asm-generic/master tip/x86/mm linus/master sparc/master v5.13-rc6 next-20210615] [cannot apply to hnaz-linux-mm/master] [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/0day-ci/linux/commits/Aneesh-Kumar-K-V/mm-rename-pud_p... base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next config: m68k-allmodconfig (attached as .config) compiler: m68k-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 # https://github.com/0day-ci/linux/commit/3eb7b4e26cc0ea2cf27fc7b23daa95f1f... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Aneesh-Kumar-K-V/mm-rename-pud_page_vaddr-to-pud_pgtable-and-make-it-return-pmd_t/20210616-162847 git checkout 3eb7b4e26cc0ea2cf27fc7b23daa95f1f681cfd8 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k 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 >>): arch/m68k/mm/motorola.c: In function 'kernel_ptr_table': 265 | pmd = pgd_page_vaddr(kernel_pg_dir[i]); | ^ arch/m68k/mm/motorola.c: At top level: arch/m68k/mm/motorola.c:390:13: warning: no previous prototype for 'paging_init' [-Wmissing-prototypes] 390 | void __init paging_init(void) | ^~~~~~~~~~~ vim +265 arch/m68k/mm/motorola.c ^1da177e4c3f415 Linus Torvalds 2005-04-16 248 ^1da177e4c3f415 Linus Torvalds 2005-04-16 249 static pmd_t * __init kernel_ptr_table(void) ^1da177e4c3f415 Linus Torvalds 2005-04-16 250 { ef9285f69f0efbc Peter Zijlstra 2020-01-31 251 if (!last_pmd_table) { ^1da177e4c3f415 Linus Torvalds 2005-04-16 252 unsigned long pmd, last; ^1da177e4c3f415 Linus Torvalds 2005-04-16 253 int i; ^1da177e4c3f415 Linus Torvalds 2005-04-16 254 ^1da177e4c3f415 Linus Torvalds 2005-04-16 255 /* Find the last ptr table that was used in head.S and ^1da177e4c3f415 Linus Torvalds 2005-04-16 256 * reuse the remaining space in that page for further ^1da177e4c3f415 Linus Torvalds 2005-04-16 257 * ptr tables. ^1da177e4c3f415 Linus Torvalds 2005-04-16 258 */ ^1da177e4c3f415 Linus Torvalds 2005-04-16 259 last = (unsigned long)kernel_pg_dir; ^1da177e4c3f415 Linus Torvalds 2005-04-16 260 for (i = 0; i < PTRS_PER_PGD; i++) { 60e50f34b13e9e4 Mike Rapoport 2019-12-04 261 pud_t *pud = (pud_t *)(&kernel_pg_dir[i]); 60e50f34b13e9e4 Mike Rapoport 2019-12-04 262 60e50f34b13e9e4 Mike Rapoport 2019-12-04 263 if (!pud_present(*pud)) ^1da177e4c3f415 Linus Torvalds 2005-04-16 264 continue; 60e50f34b13e9e4 Mike Rapoport 2019-12-04 @265 pmd = pgd_page_vaddr(kernel_pg_dir[i]); ^1da177e4c3f415 Linus Torvalds 2005-04-16 266 if (pmd > last) ^1da177e4c3f415 Linus Torvalds 2005-04-16 267 last = pmd; ^1da177e4c3f415 Linus Torvalds 2005-04-16 268 } ^1da177e4c3f415 Linus Torvalds 2005-04-16 269 ef9285f69f0efbc Peter Zijlstra 2020-01-31 270 last_pmd_table = (pmd_t *)last; ^1da177e4c3f415 Linus Torvalds 2005-04-16 271 #ifdef DEBUG ef9285f69f0efbc Peter Zijlstra 2020-01-31 272 printk("kernel_ptr_init: %p\n", last_pmd_table); ^1da177e4c3f415 Linus Torvalds 2005-04-16 273 #endif ^1da177e4c3f415 Linus Torvalds 2005-04-16 274 } ^1da177e4c3f415 Linus Torvalds 2005-04-16 275 ef9285f69f0efbc Peter Zijlstra 2020-01-31 276 last_pmd_table += PTRS_PER_PMD; 41f1bf37a63ecdb Geert Uytterhoeven 2020-08-26 277 if (PAGE_ALIGNED(last_pmd_table)) { 7e158826564fbbb Geert Uytterhoeven 2020-08-26 278 last_pmd_table = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); ef9285f69f0efbc Peter Zijlstra 2020-01-31 279 if (!last_pmd_table) 8a7f97b902f4fb0 Mike Rapoport 2019-03-11 280 panic("%s: Failed to allocate %lu bytes align=%lx\n", 8a7f97b902f4fb0 Mike Rapoport 2019-03-11 281 __func__, PAGE_SIZE, PAGE_SIZE); ^1da177e4c3f415 Linus Torvalds 2005-04-16 282 ef9285f69f0efbc Peter Zijlstra 2020-01-31 283 clear_page(last_pmd_table); ef9285f69f0efbc Peter Zijlstra 2020-01-31 284 mmu_page_ctor(last_pmd_table); ^1da177e4c3f415 Linus Torvalds 2005-04-16 285 } ^1da177e4c3f415 Linus Torvalds 2005-04-16 286 ef9285f69f0efbc Peter Zijlstra 2020-01-31 287 return last_pmd_table; ^1da177e4c3f415 Linus Torvalds 2005-04-16 288 } ^1da177e4c3f415 Linus Torvalds 2005-04-16 289 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org