tree: https://github.com/norov/linux demotion-final head: f669201ff5142089471efbff9844cfc8b83522cc commit: f2d905fe922bde5baddb485d6152a431b7954e50 [5/6] sysfs: add /sys/kernel/mm/numa/demotion_list config: x86_64-randconfig-c022-20210812 (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/f2d905fe922bde5baddb485d6152a431b79... git remote add norov https://github.com/norov/linux git fetch --no-tags norov demotion-final git checkout f2d905fe922bde5baddb485d6152a431b7954e50 # 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_store': vim +3074 mm/mempolicy.c 3050 3051 static ssize_t numa_demotion_list_store(struct kobject *kobj, 3052 struct kobj_attribute *attr, 3053 const char *buf, size_t count) 3054 { 3055 nodemask_t nodes; 3056 char *nodelist; 3057 int from, to, ret; 3058 3059 nodelist = strnchr(buf, count, '>'); 3060 if (!nodelist) 3061 return -EINVAL; 3062 3063 *nodelist++ = 0; 3064 3065 ret = kstrtoint(buf, 0, &to); 3066 if (ret) 3067 return ret; 3068 3069 ret = nodelist_parse(nodelist, nodes); 3070 if (ret) 3071 return ret; 3072 3073 for_each_node_mask(from, nodes) { 3075 if (ret == -EXDEV) 3076 pr_warn("Cross-node loop for demotion: %d>%d\n", to, from); 3077 else if (ret) 3078 return ret; 3079 } 3080 3081 return count; 3082 } 3083 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org