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-rw-r--r--kernel/rcu/tree_plugin.h52
1 files changed, 7 insertions, 45 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 41021080ad..36a8b5dbf5 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1195,14 +1195,13 @@ 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)
- goto out;
+ if (rnp->boost_kthread_task)
+ return;
t = kthread_create(rcu_boost_kthread, (void *)rnp,
"rcub/%d", rnp_index);
if (WARN_ON_ONCE(IS_ERR(t)))
- goto out;
+ return;
raw_spin_lock_irqsave_rcu_node(rnp, flags);
rnp->boost_kthread_task = t;
@@ -1210,48 +1209,11 @@ 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);
}
-/*
- * Set the per-rcu_node kthread's affinity to cover all CPUs that are
- * served by the rcu_node in question. The CPU hotplug lock is still
- * held, so the value of rnp->qsmaskinit will be stable.
- *
- * We don't include outgoingcpu in the affinity set, use -1 if there is
- * no outgoing CPU. If there are no CPUs left in the affinity set,
- * this function allows the kthread to execute on any CPU.
- *
- * Any future concurrent calls are serialized via ->boost_kthread_mutex.
- */
-static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
+static struct task_struct *rcu_boost_task(struct rcu_node *rnp)
{
- struct task_struct *t = rnp->boost_kthread_task;
- unsigned long mask;
- cpumask_var_t cm;
- int cpu;
-
- if (!t)
- return;
- if (!zalloc_cpumask_var(&cm, GFP_KERNEL))
- return;
- mutex_lock(&rnp->boost_kthread_mutex);
- mask = rcu_rnp_online_cpus(rnp);
- for_each_leaf_node_possible_cpu(rnp, cpu)
- if ((mask & leaf_node_cpu_bit(rnp, cpu)) &&
- cpu != outgoingcpu)
- cpumask_set_cpu(cpu, cm);
- cpumask_and(cm, cm, housekeeping_cpumask(HK_TYPE_RCU));
- if (cpumask_empty(cm)) {
- cpumask_copy(cm, housekeeping_cpumask(HK_TYPE_RCU));
- if (outgoingcpu >= 0)
- cpumask_clear_cpu(outgoingcpu, cm);
- }
- set_cpus_allowed_ptr(t, cm);
- mutex_unlock(&rnp->boost_kthread_mutex);
- free_cpumask_var(cm);
+ return READ_ONCE(rnp->boost_kthread_task);
}
#else /* #ifdef CONFIG_RCU_BOOST */
@@ -1270,10 +1232,10 @@ static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp)
{
}
-static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
+static struct task_struct *rcu_boost_task(struct rcu_node *rnp)
{
+ return NULL;
}
-
#endif /* #else #ifdef CONFIG_RCU_BOOST */
/*