tree: https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git sched-sisdepth-v1r3 head: 29b51054eca8c8c58122830b8a747df1a4605045 commit: 29b51054eca8c8c58122830b8a747df1a4605045 [3/3] SIS_DEPTH config: riscv-randconfig-c006-20211027 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 5db7568a6a1fcb408eb8988abdaff2a225a8eb72) 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 # install riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git/commit/?id=... git remote add mel https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git git fetch --no-tags mel sched-sisdepth-v1r3 git checkout 29b51054eca8c8c58122830b8a747df1a4605045 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv clang-analyzer If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <yujie.liu(a)intel.com&gt; clang-analyzer warnings: (new ones prefixed by >>) nr *= sched_smt_weight; ^ vim +/nr +6287 kernel/sched/fair.c 8335aa1277b644 Mel Gorman 2021-06-17 6265 10e2f1acd0106c Peter Zijlstra 2016-05-09 6266 /* 10e2f1acd0106c Peter Zijlstra 2016-05-09 6267 * Scan the LLC domain for idle CPUs; this is dynamically regulated by 29b51054eca8c8 Mel Gorman 2021-10-11 6268 * the success or failure of previous scans; 10e2f1acd0106c Peter Zijlstra 2016-05-09 6269 */ c722f35b513f80 Rik van Riel 2021-03-26 6270 static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool has_idle_core, int target) 10e2f1acd0106c Peter Zijlstra 2016-05-09 6271 { 60588bfa223ff6 Cheng Jian 2019-12-13 6272 struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask); 9fe1f127b91331 Mel Gorman 2021-01-27 6273 int i, cpu, idle_cpu = -1, nr = INT_MAX; 9cfb38a7ba5a9c Wanpeng Li 2016-10-09 6274 struct sched_domain *this_sd; 29b51054eca8c8 Mel Gorman 2021-10-11 6275 int depth = 0; 10e2f1acd0106c Peter Zijlstra 2016-05-09 6276 9cfb38a7ba5a9c Wanpeng Li 2016-10-09 6277 this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); 9cfb38a7ba5a9c Wanpeng Li 2016-10-09 6278 if (!this_sd) 9cfb38a7ba5a9c Wanpeng Li 2016-10-09 6279 return -1; 9cfb38a7ba5a9c Wanpeng Li 2016-10-09 6280 bae4ec13640b09 Mel Gorman 2021-01-25 6281 cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); bae4ec13640b09 Mel Gorman 2021-01-25 6282 29b51054eca8c8 Mel Gorman 2021-10-11 6283 if (sched_feat(SIS_DEPTH)) { 29b51054eca8c8 Mel Gorman 2021-10-11 6284 depth = min_t(int, this_sd->sis_scan_depth, nr); 1ad3aaf3fcd244 Peter Zijlstra 2017-05-17 6285 b1168d8cf90943 Mel Gorman 2021-06-18 6286 if (!has_idle_core) 8335aa1277b644 Mel Gorman 2021-06-17 @6287 nr *= sched_smt_weight; 29b51054eca8c8 Mel Gorman 2021-10-11 6288 nr = depth; bae4ec13640b09 Mel Gorman 2021-01-25 6289 } 60588bfa223ff6 Cheng Jian 2019-12-13 6290 29b51054eca8c8 Mel Gorman 2021-10-11 6291 cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); 29b51054eca8c8 Mel Gorman 2021-10-11 6292 56498cfb045d71 Mel Gorman 2021-08-04 6293 for_each_cpu_wrap(cpu, cpus, target + 1) { 29b51054eca8c8 Mel Gorman 2021-10-11 6294 if (--nr < 0) { 29b51054eca8c8 Mel Gorman 2021-10-11 6295 depth = clamp(depth - 1, 1, sis_min_cores * sched_smt_weight); b1168d8cf90943 Mel Gorman 2021-06-18 6296 break; 29b51054eca8c8 Mel Gorman 2021-10-11 6297 } b1168d8cf90943 Mel Gorman 2021-06-18 6298 c722f35b513f80 Rik van Riel 2021-03-26 6299 if (has_idle_core) { 9fe1f127b91331 Mel Gorman 2021-01-27 6300 i = select_idle_core(p, cpu, cpus, &idle_cpu); 9fe1f127b91331 Mel Gorman 2021-01-27 6301 if ((unsigned int)i < nr_cpumask_bits) b1168d8cf90943 Mel Gorman 2021-06-18 6302 break; 9fe1f127b91331 Mel Gorman 2021-01-27 6303 } else { 97886d9dcd8682 Aubrey Li 2021-03-24 6304 idle_cpu = __select_idle_cpu(cpu, p); 9fe1f127b91331 Mel Gorman 2021-01-27 6305 if ((unsigned int)idle_cpu < nr_cpumask_bits) 10e2f1acd0106c Peter Zijlstra 2016-05-09 6306 break; 10e2f1acd0106c Peter Zijlstra 2016-05-09 6307 } 9fe1f127b91331 Mel Gorman 2021-01-27 6308 } 10e2f1acd0106c Peter Zijlstra 2016-05-09 6309 29b51054eca8c8 Mel Gorman 2021-10-11 6310 if ((unsigned int)idle_cpu < nr_cpumask_bits && has_idle_core) 02dbb7246c5bbb Gautham R. Shenoy 2021-05-11 6311 set_idle_cores(target, false); 9fe1f127b91331 Mel Gorman 2021-01-27 6312 29b51054eca8c8 Mel Gorman 2021-10-11 6313 if (sched_feat(SIS_DEPTH)) { 29b51054eca8c8 Mel Gorman 2021-10-11 6314 if (idle_cpu) 29b51054eca8c8 Mel Gorman 2021-10-11 6315 depth = min_t(int, depth + 1, sd->span_weight / sched_smt_weight); 29b51054eca8c8 Mel Gorman 2021-10-11 6316 if (this_sd->sis_scan_depth != depth) 29b51054eca8c8 Mel Gorman 2021-10-11 6317 this_sd->sis_scan_depth = depth; b1168d8cf90943 Mel Gorman 2021-06-18 6318 } 10e2f1acd0106c Peter Zijlstra 2016-05-09 6319 9fe1f127b91331 Mel Gorman 2021-01-27 6320 return idle_cpu; 10e2f1acd0106c Peter Zijlstra 2016-05-09 6321 } 10e2f1acd0106c Peter Zijlstra 2016-05-09 6322 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org