Hi Yi, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on mmotm/master] url: https://github.com/0day-ci/linux/commits/Yi-Wang/mm-slab-Use-kmem_cache_z... base: git://git.cmpxchg.org/linux-mmotm.git master config: x86_64-rhel-7.6 (attached as .config) compiler: gcc-9 (Debian 9.3.0-13) 9.3.0 reproduce (this is a W=1 build): # 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 warnings (new ones prefixed by >>, old ones prefixed by <<): -- -- -- -- --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org