Hi Yu, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS head: e6b6811414fe4cfc995369e8bda32fc1b4ee1d51 commit: b2f723aef027af0f194ff0c9f53f8ae6a7cb7de3 [1719/1719] blk-io-hierarchy: support to recored the number of slow IO config: x86_64-randconfig-101-20250706 (https://download.01.org/0day-ci/archive/20250706/202507061031.GhTBMLAx-lkp@i...) compiler: clang version 20.1.7 (https://github.com/llvm/llvm-project 6146a88f60492b520a36f8f8f3231e15f3cc6082) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250706/202507061031.GhTBMLAx-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/202507061031.GhTBMLAx-lkp@intel.com/ All errors (new ones prefixed by >>):

...

block/blk-io-hierarchy/debugfs.c:63:2: error: implicit declaration of function 'hierarchy_show_slow_io' [-Werror,-Wimplicit-function-declaration] 63 | hierarchy_show_slow_io(hstats_data, m); | ^ block/blk-io-hierarchy/debugfs.c:63:2: note: did you mean 'hierarchy_account_slow_io'? block/blk-io-hierarchy/iodump.h:85:1: note: 'hierarchy_account_slow_io' declared here 85 | hierarchy_account_slow_io(struct hierarchy_stage *hstage, | ^ 1 error generated.

vim +/hierarchy_show_slow_io +63 block/blk-io-hierarchy/debugfs.c 28 29 static int __hierarchy_stats_show(struct hierarchy_stats_data *hstats_data, 30 struct seq_file *m, enum stage_group stage) 31 { 32 u64 dispatched[NR_NEW_STAT_GROUPS] = {0}; 33 u64 completed[NR_NEW_STAT_GROUPS] = {0}; 34 u64 latency[NR_NEW_STAT_GROUPS] = {0}; 35 int cpu; 36 int i; 37 38 for_each_possible_cpu(cpu) { 39 struct hierarchy_stats *stat = 40 per_cpu_ptr(hstats_data->hstats, cpu); 41 42 for (i = 0; i < NR_NEW_STAT_GROUPS; ++i) { 43 dispatched[i] += stat->dispatched[i]; 44 completed[i] += stat->completed[i]; 45 latency[i] += stage_is_rq(stage) ? 46 stat->jiffies[i] : stat->nsecs[i]; 47 } 48 } 49 50 if (stage_is_rq(stage)) 51 for (i = 0; i < NR_NEW_STAT_GROUPS; ++i) 52 latency[i] = 53 jiffies_to_msecs(latency[i]) * NSEC_PER_MSEC; 54 55 seq_printf(m, "%llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu", 56 dispatched[STAT_READ], completed[STAT_READ], 57 latency[STAT_READ], dispatched[STAT_WRITE], 58 completed[STAT_WRITE], latency[STAT_WRITE], 59 dispatched[STAT_DISCARD], completed[STAT_DISCARD], 60 latency[STAT_DISCARD], dispatched[STAT_FLUSH], 61 completed[STAT_FLUSH], latency[STAT_FLUSH]); 62

63 hierarchy_show_slow_io(hstats_data, m); 64 seq_putc(m, '\n'); 65 return 0; 66 } 67

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