Hi Jing, Thank you for the patch! Yet something to improve: [auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022] url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmi... base: 7caa04b36f204a01dac65582b71d26d190a1e022 config: mips-malta_kvm_defconfig (attached as .config) compiler: mipsel-linux-gcc (GCC) 9.3.0 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/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549 git checkout aba26c018828dadbff3f53e058c161fab2b09d35 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips 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 >>, old ones prefixed by <<): --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org