Hi Muchun, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on next-20210310] [cannot apply to hnaz-linux-mm/master arm64/for-next/core tip/x86/mm linus/master v5.12-rc2 v5.12-rc1 v5.11 v5.12-rc2] [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/Muchun-Song/mm-bootmem_info-mark-register_page_bootmem_info_section-__init/20210310-161619 base: b01d57bfdc41c8f635b08b8a5af8a31217d46936 config: x86_64-randconfig-r002-20210309 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project cd9a69289c7825d54450cb6829fef2c8e0f1963a) 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 # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://github.com/0day-ci/linux/commit/d0b8d83bb423fd25a85be4a62a8bed9f8d8a0d96 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Muchun-Song/mm-bootmem_info-mark-register_page_bootmem_info_section-__init/20210310-161619 git checkout d0b8d83bb423fd25a85be4a62a8bed9f8d8a0d96 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): arch/x86/mm/init_64.c:1585:6: error: implicit declaration of function 'vmemmap_use_new_sub_pmd' [-Werror,-Wimplicit-function-declaration] vmemmap_use_new_sub_pmd(addr, next); ^ arch/x86/mm/init_64.c:1591:4: error: implicit declaration of function 'vmemmap_use_sub_pmd' [-Werror,-Wimplicit-function-declaration] vmemmap_use_sub_pmd(addr, next); ^ >> arch/x86/mm/init_64.c:1625:6: warning: no previous prototype for function 'arch_free_vmemmap_page' [-Wmissing-prototypes] void arch_free_vmemmap_page(struct page *page) ^ arch/x86/mm/init_64.c:1625:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void arch_free_vmemmap_page(struct page *page) ^ static 1 warning and 2 errors generated. -- mm/bootmem_info.c:87:11: error: implicit declaration of function 'sparse_decode_mem_map' [-Werror,-Wimplicit-function-declaration] memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); ^ >> mm/bootmem_info.c:87:9: warning: incompatible integer to pointer conversion assigning to 'struct page *' from 'int' [-Wint-conversion] memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 warning and 1 error generated. vim +/arch_free_vmemmap_page +1625 arch/x86/mm/init_64.c c2b91e2eec9678 Yinghai Lu 2008-04-12 1623 cd28b1a6791da0 Muchun Song 2021-03-09 1624 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE 92924b23a9f6de Muchun Song 2021-03-10 @1625 void arch_free_vmemmap_page(struct page *page) 92924b23a9f6de Muchun Song 2021-03-10 1626 { 92924b23a9f6de Muchun Song 2021-03-10 1627 free_bootmem_page(page); 92924b23a9f6de Muchun Song 2021-03-10 1628 } 92924b23a9f6de Muchun Song 2021-03-10 1629 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org