rcu: Move kthread_prio bounds-check to a separate function

Move the bounds-check of the kthread_prio cmdline parameter to a new
function in order to faciliate a different callsite.

Signed-off-by: Alison Chaiken <achaiken@aurora.tech>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 4e5e37e5ee3c9b8e62f539723cc7ec408b2ad473..5bf0312f66760f32ae764187cfe92bc56dfb5d5f 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4440,26 +4440,10 @@ static int rcu_pm_notify(struct notifier_block *self,
 static int __init rcu_spawn_gp_kthread(void)
 {
        unsigned long flags;
-       int kthread_prio_in = kthread_prio;
        struct rcu_node *rnp;
        struct sched_param sp;
        struct task_struct *t;
 
-       /* Force priority into range. */
-       if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 2
-           && IS_BUILTIN(CONFIG_RCU_TORTURE_TEST))
-               kthread_prio = 2;
-       else if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 1)
-               kthread_prio = 1;
-       else if (kthread_prio < 0)
-               kthread_prio = 0;
-       else if (kthread_prio > 99)
-               kthread_prio = 99;
-
-       if (kthread_prio != kthread_prio_in)
-               pr_alert("rcu_spawn_gp_kthread(): Limited prio to %d from %d\n",
-                        kthread_prio, kthread_prio_in);
-
        rcu_scheduler_fully_active = 1;
        t = kthread_create(rcu_gp_kthread, NULL, "%s", rcu_state.name);
        if (WARN_ONCE(IS_ERR(t), "%s: Could not start grace-period kthread, OOM is now expected behavior\n", __func__))
@@ -4584,6 +4568,28 @@ static void __init rcu_init_one(void)
        }
 }
 
+/*
+ * Force priority from the kernel command-line into range.
+ */
+static void __init sanitize_kthread_prio(void)
+{
+       int kthread_prio_in = kthread_prio;
+
+       if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 2
+           && IS_BUILTIN(CONFIG_RCU_TORTURE_TEST))
+               kthread_prio = 2;
+       else if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 1)
+               kthread_prio = 1;
+       else if (kthread_prio < 0)
+               kthread_prio = 0;
+       else if (kthread_prio > 99)
+               kthread_prio = 99;
+
+       if (kthread_prio != kthread_prio_in)
+               pr_alert("%s: Limited prio to %d from %d\n",
+                        __func__, kthread_prio, kthread_prio_in);
+}
+
 /*
  * Compute the rcu_node tree geometry from kernel parameters.  This cannot
  * replace the definitions in tree.h because those are needed to size
@@ -4744,6 +4750,7 @@ void __init rcu_init(void)
 
        kfree_rcu_batch_init();
        rcu_bootup_announce();
+       sanitize_kthread_prio();
        rcu_init_geometry();
        rcu_init_one();
        if (dump_tree)