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

[kernel test robot <lkp@intel.com>]

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@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 13.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230823/202308231154.SM8fedb1-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308231154.SM8fedb1-lkp@intel.com/

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