From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
Currently, RCU spawns kthreads from several different early_initcall()
functions. Although this has served RCU well for quite some time,
as more kthreads are added a more deterministic approach is required.
This commit therefore causes all of RCU's early-boot kthreads to be
spawned from a single early_initcall() function.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 4 +++-
kernel/rcu/tree.h | 1 +
kernel/rcu/tree_plugin.h | 12 +++---------
3 files changed, 7 insertions(+), 10 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 2719978ea018..eecdbe20a08e 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3491,7 +3491,7 @@ static int rcu_pm_notify(struct notifier_block *self,
}
/*
- * Spawn the kthread that handles this RCU flavor's grace periods.
+ * Spawn the kthreads that handle each RCU flavor's grace periods.
*/
static int __init rcu_spawn_gp_kthread(void)
{
@@ -3500,6 +3500,7 @@ static int __init rcu_spawn_gp_kthread(void)
struct rcu_state *rsp;
struct task_struct *t;
+ rcu_scheduler_fully_active = 1;
for_each_rcu_flavor(rsp) {
t = kthread_run(rcu_gp_kthread, rsp, "%s", rsp->name);
BUG_ON(IS_ERR(t));
@@ -3509,6 +3510,7 @@ static int __init rcu_spawn_gp_kthread(void)
raw_spin_unlock_irqrestore(&rnp->lock, flags);
rcu_spawn_nocb_kthreads(rsp);
}
+ rcu_spawn_boost_kthreads();
return 0;
}
early_initcall(rcu_spawn_gp_kthread);
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 71e64c718f75..bd7b63da9a8c 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -572,6 +572,7 @@ static void rcu_preempt_do_callbacks(void);
static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
struct rcu_node *rnp);
#endif /* #ifdef CONFIG_RCU_BOOST */
+static void __init rcu_spawn_boost_kthreads(void);
static void rcu_prepare_kthreads(int cpu);
static void rcu_cleanup_after_idle(int cpu);
static void rcu_prepare_for_idle(int cpu);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 735dc48634e7..f5314cc20750 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1463,14 +1463,13 @@ static struct smp_hotplug_thread rcu_cpu_thread_spec = {
};
/*
- * Spawn all kthreads -- called as soon as the scheduler is running.
+ * Spawn boost kthreads -- called as soon as the scheduler is running.
*/
-static int __init rcu_spawn_kthreads(void)
+static void __init rcu_spawn_boost_kthreads(void)
{
struct rcu_node *rnp;
int cpu;
- rcu_scheduler_fully_active = 1;
for_each_possible_cpu(cpu)
per_cpu(rcu_cpu_has_work, cpu) = 0;
BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
@@ -1480,9 +1479,7 @@ static int __init rcu_spawn_kthreads(void)
rcu_for_each_leaf_node(rcu_state_p, rnp)
(void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp);
}
- return 0;
}
-early_initcall(rcu_spawn_kthreads);
static void rcu_prepare_kthreads(int cpu)
{
@@ -1520,12 +1517,9 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
{
}
-static int __init rcu_scheduler_really_started(void)
+static void __init rcu_spawn_boost_kthreads(void)
{
- rcu_scheduler_fully_active = 1;
- return 0;
}
-early_initcall(rcu_scheduler_really_started);
static void rcu_prepare_kthreads(int cpu)
{
--
1.8.1.5
--
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