Hi Mike, I love your patch! Yet something to improve: [auto build test ERROR on linux/master] [also build test ERROR on v5.15] [cannot apply to hnaz-mm/master linus/master next-20211112] [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/Mike-Kravetz/hugetlb-add-demote-... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 5816b3e6577eaa676ceb00a848f0fd65fe2adc29 config: x86_64-allyesconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/5829c115b143a240099ed1da793e684f6... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Mike-Kravetz/hugetlb-add-demote-split-page-functionality/20211002-015415 git checkout 5829c115b143a240099ed1da793e684f6dd8c2d8 # save the attached .config to linux build tree make W=1 ARCH=x86_64 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 >>): mm/hugetlb.c: In function 'demote_size_show': 3533 | unsigned long demote_size; | ^~~~~~~~~~~ cc1: all warnings being treated as errors vim +/demote_size +3533 mm/hugetlb.c 3528 3529 static ssize_t demote_size_show(struct kobject *kobj, 3530 struct kobj_attribute *attr, char *buf) 3531 { 3532 struct hstate *h; 3534 int nid; 3535 3536 h = kobj_to_hstate(kobj, &nid); 3537 demote_size = h->demote_order; 3538 3539 return sysfs_emit(buf, "%lukB\n", 3540 (unsigned long)(PAGE_SIZE << h->demote_order) / SZ_1K); 3541 } 3542 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org