tree: https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git queue-5.4 head: 1aa393e1b468d93c753bf778b182e034839a9b0f commit: ca555f5a71abac01e56232dd7526b1e97b5a10e3 [169/174] perf/core: Flush PMU internal buffers for per-CPU events config: i386-randconfig-m021-20210315 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git/c... git remote add sashal-linux-stable https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git git fetch --no-tags sashal-linux-stable queue-5.4 git checkout ca555f5a71abac01e56232dd7526b1e97b5a10e3 # save the attached .config to linux build tree make W=1 ARCH=i386 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 >>): 3304 | static void perf_pmu_sched_task(struct task_struct *prev, | ^~~~~~~~~~~~~~~~~~~ kernel/events/core.c:3278:13: note: previous definition of 'perf_pmu_sched_task' was here 3278 | static void perf_pmu_sched_task(struct task_struct *prev, | ^~~~~~~~~~~~~~~~~~~ kernel/events/core.c: In function 'perf_pmu_sched_task': 3318 | __perf_pmu_sched_task(cpuctx, sched_in); | ^~~~~~~~~~~~~~~~~~~~~ | perf_pmu_sched_task kernel/events/core.c: At top level: kernel/events/core.c:5397:13: warning: no previous prototype for 'arch_perf_update_userpage' [-Wmissing-prototypes] 5397 | void __weak arch_perf_update_userpage( | ^~~~~~~~~~~~~~~~~~~~~~~~~ kernel/events/core.c:3278:13: warning: 'perf_pmu_sched_task' defined but not used [-Wunused-function] 3278 | static void perf_pmu_sched_task(struct task_struct *prev, | ^~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/perf_pmu_sched_task +3304 kernel/events/core.c 3303 3305 struct task_struct *next, 3306 bool sched_in) 3307 { 3308 struct perf_cpu_context *cpuctx; 3309 3310 if (prev == next) 3311 return; 3312 3313 list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) { 3314 /* will be handled in perf_event_context_sched_in/out */ 3315 if (cpuctx->task_ctx) 3316 continue; 3317 3319 } 3320 } 3321 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org