On Wed, Dec 15, 2021 at 11:05:05AM +0800, kernel test robot wrote: > 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-lkp@xxxxxxxxx/config) > 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@xxxxxxxxx> I am folding the fix into the original with attribution, thank you! Thanx, Paul > 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 } > > 1262 mutex_unlock(&rdp_gp->nocb_gp_kthread_mutex); > 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@xxxxxxxxxxxx
