Re: [PATCH v2 2/2] fork: group allocation of per-cpu counters for mm struct

From: kernel test robot
Date: Wed Aug 23 2023 - 00:18:03 EST


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

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