tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 6d9bd4ad4ca08b1114e814c2c42383b8b13be631 commit: 3eb7a613cb25789b954064cf6e310f6b5ca92c03 [5127/5417] mm: move page-writeback sysctls to their own file config: hexagon-randconfig-r041-20220213 (https://download.01.org/0day-ci/archive/20220214/202202140744.t6UIHhn5-lk...) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project ea071884b0cc7210b3cc5fe858f0e892a779a23b) 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://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 3eb7a613cb25789b954064cf6e310f6b5ca92c03 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon 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 >>): static const unsigned long dirty_bytes_min = 2 * PAGE_SIZE; ^ mm/page-writeback.c:509:12: error: unused function 'dirty_background_ratio_handler' [-Werror,-Wunused-function] static int dirty_background_ratio_handler(struct ctl_table *table, int write, ^ mm/page-writeback.c:520:12: error: unused function 'dirty_background_bytes_handler' [-Werror,-Wunused-function] static int dirty_background_bytes_handler(struct ctl_table *table, int write, ^ mm/page-writeback.c:531:12: error: unused function 'dirty_ratio_handler' [-Werror,-Wunused-function] static int dirty_ratio_handler(struct ctl_table *table, int write, void *buffer, ^ mm/page-writeback.c:545:12: error: unused function 'dirty_bytes_handler' [-Werror,-Wunused-function] static int dirty_bytes_handler(struct ctl_table *table, int write, ^ mm/page-writeback.c:2002:12: error: unused function 'dirty_writeback_centisecs_handler' [-Werror,-Wunused-function] static int dirty_writeback_centisecs_handler(struct ctl_table *table, int write, ^ 6 errors generated. 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