Hi Mateusz, kernel test robot noticed the following build errors: [auto build test ERROR on dennis-percpu/for-next] [also build test ERROR on linus/master v6.5-rc7 next-20230822] [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/Mateusz-Guzik/pcpcntr-add-group-allocation-free/20230823-024312 base: https://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu.git for-next patch link: https://lore.kernel.org/r/20230822184152.2194558-3-mjguzik%40gmail.com patch subject: [PATCH v2 2/2] fork: group allocation of per-cpu counters for mm struct config: arm-randconfig-r005-20230823 (https://download.01.org/0day-ci/archive/20230823/202308231154.SM8fedb1-lkp@xxxxxxxxx/config) compiler: arm-linux-gnueabi-gcc (GCC) 13.2.0 reproduce: (https://download.01.org/0day-ci/archive/20230823/202308231154.SM8fedb1-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/202308231154.SM8fedb1-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): kernel/fork.c: In function '__mmdrop': >> kernel/fork.c:926:9: error: implicit declaration of function 'percpu_counter_destroy_many'; did you mean 'percpu_counter_destroy'? [-Werror=implicit-function-declaration] 926 | percpu_counter_destroy_many(mm->rss_stat, NR_MM_COUNTERS); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ | percpu_counter_destroy kernel/fork.c: In function 'mm_init': >> kernel/fork.c:1299:13: error: implicit declaration of function 'percpu_counter_init_many'; did you mean 'percpu_counter_init'? [-Werror=implicit-function-declaration] 1299 | if (percpu_counter_init_many(mm->rss_stat, 0, GFP_KERNEL_ACCOUNT, NR_MM_COUNTERS)) | ^~~~~~~~~~~~~~~~~~~~~~~~ | percpu_counter_init cc1: some warnings being treated as errors vim +926 kernel/fork.c 904 905 /* 906 * Called when the last reference to the mm 907 * is dropped: either by a lazy thread or by 908 * mmput. Free the page directory and the mm. 909 */ 910 void __mmdrop(struct mm_struct *mm) 911 { 912 BUG_ON(mm == &init_mm); 913 WARN_ON_ONCE(mm == current->mm); 914 915 /* Ensure no CPUs are using this as their lazy tlb mm */ 916 cleanup_lazy_tlbs(mm); 917 918 WARN_ON_ONCE(mm == current->active_mm); 919 mm_free_pgd(mm); 920 destroy_context(mm); 921 mmu_notifier_subscriptions_destroy(mm); 922 check_mm(mm); 923 put_user_ns(mm->user_ns); 924 mm_pasid_drop(mm); 925 mm_destroy_cid(mm); > 926 percpu_counter_destroy_many(mm->rss_stat, NR_MM_COUNTERS); 927 928 free_mm(mm); 929 } 930 EXPORT_SYMBOL_GPL(__mmdrop); 931 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki