[norov:demotion-final 5/6] mm/mempolicy.c:3043: undefined reference to `node_demotion'

[kernel test robot]

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/ada82b5573a980b7c5a7aeae488ea6c7213e6429
        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@xxxxxxxxx>

All errors (new ones prefixed by >>):

   ld: mm/mempolicy.o: in function `numa_demotion_list_show':
>> mm/mempolicy.c:3043: undefined reference to `node_demotion'


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) {
> 3043			len = sysfs_emit_at(buf, pos, "%d %d\n", n, node_demotion[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@xxxxxxxxxxxx

Attachment: .config.gz
Description: application/gzip