Hi Ze, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git OLK-6.6 head: be758a5796c3d280deb877699c41fd0cd04e1deb commit: 390982f28c5796a1e590381044630b768e6b9696 [2909/2909] mm/mem_sampling: Add sysctl control for NUMA balancing integration config: arm64-randconfig-r121-20250923 (https://download.01.org/0day-ci/archive/20250923/202509231319.810I86nl-lkp@i...) compiler: clang version 16.0.6 (https://github.com/llvm/llvm-project 7cbf1a2591520c2491aa35339f227775f4d3adf6) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250923/202509231319.810I86nl-lkp@i...) 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/202509231319.810I86nl-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] 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 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] 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 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] 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] static const int mem_sampling_max_value = MEM_SAMPLING_MAX_VALUE; ^ 4 warnings generated.

Kconfig warnings: (for reference only) WARNING: unmet direct dependencies detected for ARM_SPE_MEM_SAMPLING Depends on [n]: ARM_SPE_PMU [=n] Selected by [y]: - MEM_SAMPLING [=y] && ARM64 [=y] 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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