Hi Zi, Thank you for the patch! Yet something to improve: [auto build test ERROR on akpm-mm/mm-everything] [also build test ERROR on linus/master v6.3-rc4 next-20230329] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Zi-Yan/mm-memcg-use-order-instead-of-nr-in-split_page_memcg/20230329-091809 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/20230329011712.3242298-5-zi.yan%40sent.com patch subject: [PATCH v2 4/7] mm: page_owner: add support for splitting to any order in split page_owner. config: i386-randconfig-m021 (https://download.01.org/0day-ci/archive/20230329/202303291732.7OqWI96E-lkp@xxxxxxxxx/config) compiler: gcc-11 (Debian 11.3.0-8) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/6d1831c0e01a1a742e026454fe6e5643e08c5985 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Zi-Yan/mm-memcg-use-order-instead-of-nr-in-split_page_memcg/20230329-091809 git checkout 6d1831c0e01a1a742e026454fe6e5643e08c5985 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=i386 olddefconfig make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Link: https://lore.kernel.org/oe-kbuild-all/202303291732.7OqWI96E-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): mm/page_owner.c: In function '__split_page_owner': >> mm/page_owner.c:226:28: error: implicit declaration of function 'lookup_page_ext' [-Werror=implicit-function-declaration] 226 | page_ext = lookup_page_ext(page + i); | ^~~~~~~~~~~~~~~ mm/page_owner.c:226:26: warning: assignment to 'struct page_ext *' from 'int' makes pointer from integer without a cast [-Wint-conversion] 226 | page_ext = lookup_page_ext(page + i); | ^ cc1: some warnings being treated as errors vim +/lookup_page_ext +226 mm/page_owner.c 213 214 void __split_page_owner(struct page *page, int old_order, int new_order) 215 { 216 int i; 217 struct page_ext *page_ext = page_ext_get(page); 218 struct page_owner *page_owner; 219 unsigned int old_nr = 1 << old_order; 220 unsigned int new_nr = 1 << new_order; 221 222 if (unlikely(!page_ext)) 223 return; 224 225 for (i = 0; i < old_nr; i += new_nr) { > 226 page_ext = lookup_page_ext(page + i); 227 page_owner = get_page_owner(page_ext); 228 page_owner->order = new_order; 229 } 230 page_ext_put(page_ext); 231 } 232 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests