[openeuler:OLK-6.6 2380/2380] mm/mem_sampling.c:35:18: warning: unused variable 'mem_sampling_min_value'

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

tree:   https://gitee.com/openeuler/kernel.git OLK-6.6
head:   a7f4bf73c34996ee6cdda292e8f906a9c30879de
commit: 390982f28c5796a1e590381044630b768e6b9696 [2380/2380] mm/mem_sampling: Add sysctl control for NUMA balancing integration
config: arm64-randconfig-r112-20250610 (https://download.01.org/0day-ci/archive/20250610/202506101037.VkwcnAFd-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce: (https://download.01.org/0day-ci/archive/20250610/202506101037.VkwcnAFd-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/202506101037.VkwcnAFd-lkp@intel.com/

All warnings (new ones prefixed by >>):

   mm/mem_sampling.c:68:6: warning: no previous prototype for function 'mem_sampling_record_cb_register' [-Wmissing-prototypes]
      68 | void mem_sampling_record_cb_register(mem_sampling_record_cb_type cb)
         |      ^
   mm/mem_sampling.c:68:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
      68 | void mem_sampling_record_cb_register(mem_sampling_record_cb_type cb)
         | ^
         | static 
   mm/mem_sampling.c:85:6: warning: no previous prototype for function 'mem_sampling_record_cb_unregister' [-Wmissing-prototypes]
      85 | void mem_sampling_record_cb_unregister(mem_sampling_record_cb_type cb)
         |      ^
   mm/mem_sampling.c:85:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
      85 | void mem_sampling_record_cb_unregister(mem_sampling_record_cb_type cb)
         | ^
         | static 
>> mm/mem_sampling.c:35:18: warning: unused variable 'mem_sampling_min_value' [-Wunused-const-variable]
      35 | static const int mem_sampling_min_value = MEM_SAMPLING_MIN_VALUE;
         |                  ^~~~~~~~~~~~~~~~~~~~~~
>> mm/mem_sampling.c:36:18: warning: unused variable 'mem_sampling_max_value' [-Wunused-const-variable]
      36 | static const int mem_sampling_max_value = MEM_SAMPLING_MAX_VALUE;
         |                  ^~~~~~~~~~~~~~~~~~~~~~
   4 warnings generated.


vim +/mem_sampling_min_value +35 mm/mem_sampling.c

    34	
  > 35	static const int mem_sampling_min_value = MEM_SAMPLING_MIN_VALUE;
  > 36	static const int mem_sampling_max_value = MEM_SAMPLING_MAX_VALUE;
    37	
    38	/* keep track of who use the SPE */
    39	DEFINE_PER_CPU(enum arm_spe_user_e, arm_spe_user);
    40	EXPORT_PER_CPU_SYMBOL_GPL(arm_spe_user);
    41	
    42	enum mem_sampling_saved_state_e {
    43		MEM_SAMPLING_STATE_ENABLE,
    44		MEM_SAMPLING_STATE_DISABLE,
    45		MEM_SAMPLING_STATE_EMPTY,
    46	};
    47	enum mem_sampling_saved_state_e mem_sampling_saved_state = MEM_SAMPLING_STATE_EMPTY;
    48	
    49	/*
    50	 * Callbacks should be registered using mem_sampling_record_cb_register()
    51	 * by NUMA, DAMON and etc during their initialisation.
    52	 * Callbacks will be invoked on new hardware pmu records caputured.
    53	 */
    54	typedef void (*mem_sampling_record_cb_type)(struct mem_sampling_record *record);
    55	
    56	struct mem_sampling_record_cb_list_entry {
    57		struct list_head list;
    58		mem_sampling_record_cb_type cb;
    59	};
    60	LIST_HEAD(mem_sampling_record_cb_list);
    61	
    62	struct mem_sampling_numa_access_work {
    63		struct callback_head work;
    64		u64 vaddr, paddr;
    65		int cpu;
    66	};
    67	
    68	void mem_sampling_record_cb_register(mem_sampling_record_cb_type cb)
    69	{
    70		struct mem_sampling_record_cb_list_entry *cb_entry, *tmp;
    71	
    72		list_for_each_entry_safe(cb_entry, tmp, &mem_sampling_record_cb_list, list) {
    73			if (cb_entry->cb == cb)
    74				return;
    75		}
    76	
    77		cb_entry = kmalloc(sizeof(struct mem_sampling_record_cb_list_entry), GFP_KERNEL);
    78		if (!cb_entry)
    79			return;
    80	
    81		cb_entry->cb = cb;
    82		list_add(&(cb_entry->list), &mem_sampling_record_cb_list);
    83	}
    84	
  > 85	void mem_sampling_record_cb_unregister(mem_sampling_record_cb_type cb)
    86	{
    87		struct mem_sampling_record_cb_list_entry *cb_entry, *tmp;
    88	
    89		list_for_each_entry_safe(cb_entry, tmp, &mem_sampling_record_cb_list, list) {
    90			if (cb_entry->cb == cb) {
    91				list_del(&cb_entry->list);
    92				kfree(cb_entry);
    93				return;
    94			}
    95		}
    96	}
    97	

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