tree: https://github.com/norov/linux demotion-final head: 260e1fe9fc779f2f5182d595e375fa7ded4ff435 commit: ada82b5573a980b7c5a7aeae488ea6c7213e6429 [5/6] sysfs: add /sys/kernel/mm/numa/demotion_list config: x86_64-randconfig-a001-20210816 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/norov/linux/commit/ada82b5573a980b7c5a7aeae488ea6c7213... git remote add norov https://github.com/norov/linux git fetch --no-tags norov demotion-final git checkout ada82b5573a980b7c5a7aeae488ea6c7213e6429 # save the attached .config to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): ld: mm/mempolicy.o: in function `numa_demotion_list_show': vim +3043 mm/mempolicy.c 3032 3033 static struct kobj_attribute numa_demotion_enabled_attr = 3034 __ATTR(demotion_enabled, 0644, numa_demotion_enabled_show, 3035 numa_demotion_enabled_store); 3036 3037 static ssize_t numa_demotion_list_show(struct kobject *kobj, 3038 struct kobj_attribute *attr, char *buf) 3039 { 3040 int len, n, pos = 0; 3041 3042 for_each_online_node(n) { 3044 if (len > 0) 3045 pos += len; 3046 } 3047 3048 return pos; 3049 } 3050 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org