Hi Yosry, kernel test robot noticed the following build warnings: [auto build test WARNING on akpm-mm/mm-everything] [also build test WARNING on linus/master next-20230830] [cannot apply to v6.5] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Yosry-Ahmed/mm-memcg-properly-name-and-document-unified-stats-flushing/20230831-015518 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/20230830175335.1536008-5-yosryahmed%40google.com patch subject: [PATCH v3 4/4] mm: memcg: use non-unified stats flushing for userspace reads config: i386-randconfig-r013-20230831 (https://download.01.org/0day-ci/archive/20230831/202308311025.538QuXBV-lkp@xxxxxxxxx/config) compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230831/202308311025.538QuXBV-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202308311025.538QuXBV-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> mm/memcontrol.c:667:6: warning: no previous prototype for function 'mem_cgroup_user_flush_stats' [-Wmissing-prototypes] void mem_cgroup_user_flush_stats(struct mem_cgroup *memcg) ^ mm/memcontrol.c:667:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void mem_cgroup_user_flush_stats(struct mem_cgroup *memcg) ^ static 1 warning generated. vim +/mem_cgroup_user_flush_stats +667 mm/memcontrol.c 658 659 /* 660 * mem_cgroup_user_flush_stats - do a stats flush for a user read 661 * @memcg: memory cgroup to flush 662 * 663 * Flush the subtree of @memcg. A mutex is used for userspace readers to gate 664 * the global rstat spinlock. This protects in-kernel flushers from userspace 665 * readers hogging the lock. 666 */ > 667 void mem_cgroup_user_flush_stats(struct mem_cgroup *memcg) 668 { 669 mutex_lock(&stats_user_flush_mutex); 670 do_stats_flush(memcg); 671 mutex_unlock(&stats_user_flush_mutex); 672 } 673 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki