[kbuild-all] [tip:smp/urgent 1/1] kernel/cpu.c:1353:2: error: implicit declaration of function 'cpu_up_down_serialize_trainwrecks'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git smp/urgent head: 64c71be97c02c3d3f24dea7c290912ad300538b9 commit: 64c71be97c02c3d3f24dea7c290912ad300538b9 [1/1] cpu/hotplug: Cure the cpusets trainwreck config: mips-randconfig-r005-20210620 (attached as .config) compiler: mips64-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=64... git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git git fetch --no-tags tip smp/urgent git checkout 64c71be97c02c3d3f24dea7c290912ad300538b9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): kernel/cpu.c: In function '_cpu_up': 1353 | cpu_up_down_serialize_trainwrecks(tasks_frozen); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/cpu_up_down_serialize_trainwrecks +1353 kernel/cpu.c 1295 1296 /* Requires cpu_add_remove_lock to be held */ 1297 static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target) 1298 { 1299 struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); 1300 struct task_struct *idle; 1301 int ret = 0; 1302 1303 cpus_write_lock(); 1304 1305 if (!cpu_present(cpu)) { 1306 ret = -EINVAL; 1307 goto out; 1308 } 1309 1310 /* 1311 * The caller of cpu_up() might have raced with another 1312 * caller. Nothing to do. 1313 */ 1314 if (st->state >= target) 1315 goto out; 1316 1317 if (st->state == CPUHP_OFFLINE) { 1318 /* Let it fail before we try to bring the cpu up */ 1319 idle = idle_thread_get(cpu); 1320 if (IS_ERR(idle)) { 1321 ret = PTR_ERR(idle); 1322 goto out; 1323 } 1324 } 1325 1326 cpuhp_tasks_frozen = tasks_frozen; 1327 1328 cpuhp_set_state(st, target); 1329 /* 1330 * If the current CPU state is in the range of the AP hotplug thread, 1331 * then we need to kick the thread once more. 1332 */ 1333 if (st->state > CPUHP_BRINGUP_CPU) { 1334 ret = cpuhp_kick_ap_work(cpu); 1335 /* 1336 * The AP side has done the error rollback already. Just 1337 * return the error code.. 1338 */ 1339 if (ret) 1340 goto out; 1341 } 1342 1343 /* 1344 * Try to reach the target state. We max out on the BP at 1345 * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is 1346 * responsible for bringing it up to the target state. 1347 */ 1348 target = min((int)target, CPUHP_BRINGUP_CPU); 1349 ret = cpuhp_up_callbacks(cpu, st, target); 1350 out: 1351 cpus_write_unlock(); 1352 arch_smt_update(); 1354 return ret; 1355 } 1356 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org