diff options
| -rw-r--r-- | kernel/rcu/tree.c | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 3 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 10 |
3 files changed, 12 insertions, 2 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a4c25a6283b0..d1d1a8c51223 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4570,6 +4570,7 @@ static void __init rcu_init_one(void) init_waitqueue_head(&rnp->exp_wq[2]); init_waitqueue_head(&rnp->exp_wq[3]); spin_lock_init(&rnp->exp_lock); + mutex_init(&rnp->boost_kthread_mutex); } } diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 486fc901bd08..3b8b60de07c3 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -110,6 +110,9 @@ struct rcu_node { /* side effect, not as a lock. */ unsigned long boost_time; /* When to start boosting (jiffies). */ + struct mutex boost_kthread_mutex; + /* Exclusion for thread spawning and affinity */ + /* manipulation. */ struct task_struct *boost_kthread_task; /* kthread that takes care of priority */ /* boosting for this rcu_node structure. */ diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index c5b45c2f68a1..07845dcd33c5 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1172,15 +1172,16 @@ static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp) struct sched_param sp; struct task_struct *t; + mutex_lock(&rnp->boost_kthread_mutex); if (rnp->boost_kthread_task || !rcu_scheduler_fully_active) - return; + goto out; rcu_state.boost = 1; t = kthread_create(rcu_boost_kthread, (void *)rnp, "rcub/%d", rnp_index); if (WARN_ON_ONCE(IS_ERR(t))) - return; + goto out; raw_spin_lock_irqsave_rcu_node(rnp, flags); rnp->boost_kthread_task = t; @@ -1188,6 +1189,9 @@ static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp) sp.sched_priority = kthread_prio; sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); wake_up_process(t); /* get to TASK_INTERRUPTIBLE quickly. */ + + out: + mutex_unlock(&rnp->boost_kthread_mutex); } /* @@ -1210,6 +1214,7 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu) return; if (!zalloc_cpumask_var(&cm, GFP_KERNEL)) return; + mutex_lock(&rnp->boost_kthread_mutex); for_each_leaf_node_possible_cpu(rnp, cpu) if ((mask & leaf_node_cpu_bit(rnp, cpu)) && cpu != outgoingcpu) @@ -1218,6 +1223,7 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu) if (cpumask_weight(cm) == 0) cpumask_copy(cm, housekeeping_cpumask(HK_FLAG_RCU)); set_cpus_allowed_ptr(t, cm); + mutex_unlock(&rnp->boost_kthread_mutex); free_cpumask_var(cm); } |