Hi Yafang,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Yafang-Shao/mm-page_ext-split-page_ext-flags/20221217-190044
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20221217105833.24851-3-laoar.shao%40gmail.com
patch subject: [PATCH -mm 2/2] mm: page_idle: split 32bit page_idle's flag from the common flags
config: arc-randconfig-r001-20221217
compiler: arceb-elf-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/b2ccea224a74e091007c4c772b78b8163bb11b6c
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Yafang-Shao/mm-page_ext-split-page_ext-flags/20221217-190044
        git checkout b2ccea224a74e091007c4c772b78b8163bb11b6c
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   arceb-elf-ld: mm/filemap.o: in function `get_page_idle':
   include/linux/page_idle.h:24: undefined reference to `page_idle_ops'
>> arceb-elf-ld: include/linux/page_idle.h:24: undefined reference to `page_idle_ops'
   arceb-elf-ld: mm/swap.o: in function `get_page_idle':
   include/linux/page_idle.h:24: undefined reference to `page_idle_ops'
>> arceb-elf-ld: include/linux/page_idle.h:24: undefined reference to `page_idle_ops'
   arceb-elf-ld: mm/rmap.o: in function `get_page_idle':
   include/linux/page_idle.h:24: undefined reference to `page_idle_ops'
   arceb-elf-ld: mm/rmap.o:include/linux/page_idle.h:24: more undefined references to `page_idle_ops' follow

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp