tree: https://github.com/hnaz/linux-mm master head: 31e523f69aa14a1f4ba298c63034d8dc62c4aae7 commit: d2d94dec619e0ab7f6805f3bc6e7932d71bfe765 [92/304] mm: move page-writeback sysctls to their own file config: powerpc64-randconfig-s032-20220213 (https://download.01.org/0day-ci/archive/20220213/202202131948.o0qQogUI-lk...) compiler: powerpc64-linux-gcc (GCC) 11.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.4-dirty # https://github.com/hnaz/linux-mm/commit/d2d94dec619e0ab7f6805f3bc6e7932d7... git remote add hnaz-mm https://github.com/hnaz/linux-mm git fetch --no-tags hnaz-mm master git checkout d2d94dec619e0ab7f6805f3bc6e7932d71bfe765 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=powerpc SHELL=/bin/bash 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/page-writeback.c:2002:12: error: 'dirty_writeback_centisecs_handler' defined but not used [-Werror=unused-function] 2002 | static int dirty_writeback_centisecs_handler(struct ctl_table *table, int write, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/page-writeback.c:545:12: error: 'dirty_bytes_handler' defined but not used [-Werror=unused-function] 545 | static int dirty_bytes_handler(struct ctl_table *table, int write, | ^~~~~~~~~~~~~~~~~~~ mm/page-writeback.c:531:12: error: 'dirty_ratio_handler' defined but not used [-Werror=unused-function] 531 | static int dirty_ratio_handler(struct ctl_table *table, int write, void *buffer, | ^~~~~~~~~~~~~~~~~~~ mm/page-writeback.c:520:12: error: 'dirty_background_bytes_handler' defined but not used [-Werror=unused-function] 520 | static int dirty_background_bytes_handler(struct ctl_table *table, int write, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/page-writeback.c:509:12: error: 'dirty_background_ratio_handler' defined but not used [-Werror=unused-function] 509 | static int dirty_background_ratio_handler(struct ctl_table *table, int write, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 93 | static const unsigned long dirty_bytes_min = 2 * PAGE_SIZE; | ^~~~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/dirty_bytes_min +93 mm/page-writeback.c 91 92 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */ 94 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org