tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 0bafb8f3ebc84525d0ae0fcea22d12151b99312f commit: fd1d05c6c00a3a6cbbb7156c1a99396df33f75b6 [6371/6993] rcu/nocb: Handle concurrent nocb kthreads creation config: x86_64-randconfig-m001-20211214 (https://download.01.org/0day-ci/archive/20211215/202112151130.18unyr6u-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; smatch warnings: kernel/rcu/tree_nocb.h:1262 rcu_spawn_cpu_nocb_kthread() warn: inconsistent indenting vim +1262 kernel/rcu/tree_nocb.h 1231 1232 /* 1233 * If the specified CPU is a no-CBs CPU that does not already have its 1234 * rcuo CB kthread, spawn it. Additionally, if the rcuo GP kthread 1235 * for this CPU's group has not yet been created, spawn it as well. 1236 */ 1237 static void rcu_spawn_cpu_nocb_kthread(int cpu) 1238 { 1239 struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); 1240 struct rcu_data *rdp_gp; 1241 struct task_struct *t; 1242 1243 if (!rcu_scheduler_fully_active || !rcu_nocb_is_setup) 1244 return; 1245 1246 /* If there already is an rcuo kthread, then nothing to do. */ 1247 if (rdp->nocb_cb_kthread) 1248 return; 1249 1250 /* If we didn't spawn the GP kthread first, reorganize! */ 1251 rdp_gp = rdp->nocb_gp_rdp; 1252 mutex_lock(&rdp_gp->nocb_gp_kthread_mutex); 1253 if (!rdp_gp->nocb_gp_kthread) { 1254 t = kthread_run(rcu_nocb_gp_kthread, rdp_gp, 1255 "rcuog/%d", rdp_gp->cpu); 1256 if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo GP kthread, OOM is now expected behavior\n", __func__)) { 1257 mutex_unlock(&rdp_gp->nocb_gp_kthread_mutex); 1258 return; 1259 } 1260 WRITE_ONCE(rdp_gp->nocb_gp_kthread, t); 1261 } 1263 1264 /* Spawn the kthread for this CPU. */ 1265 t = kthread_run(rcu_nocb_cb_kthread, rdp, 1266 "rcuo%c/%d", rcu_state.abbr, cpu); 1267 if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo CB kthread, OOM is now expected behavior\n", __func__)) 1268 return; 1269 WRITE_ONCE(rdp->nocb_cb_kthread, t); 1270 WRITE_ONCE(rdp->nocb_gp_kthread, rdp_gp->nocb_gp_kthread); 1271 } 1272 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org