Hi Muchun, Thank you for the patch! Yet something to improve: [auto build test ERROR on hnaz-mm/master] [also build test ERROR on next-20220414] [cannot apply to tip/x86/mm masahiroy-kbuild/for-next linus/master v5.18-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/intel-lab-lkp/linux/commits/Muchun-Song/add-hugetlb_optimize_vmemmap-sysctl/20220412-191713 base: https://github.com/hnaz/linux-mm master config: s390-randconfig-r025-20220414 (https://download.01.org/0day-ci/archive/20220415/202204151043.JSdPGnod-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 6b7e6ea489f6dd45a9b0da9ac20871560917b9b0) 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 s390 cross compiling tool for clang build # apt-get install binutils-s390x-linux-gnu # https://github.com/intel-lab-lkp/linux/commit/bb63a010442d551909f826b4c05bf707a6dff052 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Muchun-Song/add-hugetlb_optimize_vmemmap-sysctl/20220412-191713 git checkout bb63a010442d551909f826b4c05bf707a6dff052 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 prepare If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): In file included from <built-in>:2: >> include/linux/kconfig.h:8:10: fatal error: 'generated/autoconf_ext.h' file not found #include <generated/autoconf_ext.h> ^~~~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated. make[2]: *** [scripts/Makefile.host:111: arch/s390/tools/gen_facilities] Error 1 make[2]: Target 'kapi' not remade because of errors. make[1]: *** [arch/s390/Makefile:148: archprepare] Error 2 make[1]: Target 'prepare' not remade because of errors. make: *** [Makefile:226: __sub-make] Error 2 make: Target 'prepare' not remade because of errors. vim +8 include/linux/kconfig.h 6 7 #ifndef __EXCLUDE_AUTOCONF_EXT_H > 8 #include <generated/autoconf_ext.h> 9 #endif 10 -- 0-DAY CI Kernel Test Service https://01.org/lkp