From: Alison Chaiken <achaiken@aurora.tech>
To: tglx@linutronix.de
Cc: peterz@infradead.org, paulmck@kernel.org,
valentin.schneider@arm.com, frederic@kernel.org,
linux-kernel@vger.kernel.org, glenn@aurora.tech,
alison@she-devel.com, Alison Chaiken <achaiken@aurora.tech>
Subject: [PATCH 1/4] RCU: move kthread_prio bounds-check to a separate function
Date: Tue, 11 Jan 2022 15:32:50 -0800 [thread overview]
Message-ID: <20220111233253.21692-2-achaiken@aurora.tech> (raw)
In-Reply-To: <20220111233253.21692-1-achaiken@aurora.tech>
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>
---
kernel/rcu/tree.c | 39 +++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 16 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9a04550cc54b..15cabb288a1c 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4404,26 +4404,10 @@ 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__))
@@ -4548,6 +4532,28 @@ 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
@@ -4708,6 +4714,7 @@ void __init rcu_init(void)
kfree_rcu_batch_init();
rcu_bootup_announce();
+ sanitize_kthread_prio();
rcu_init_geometry();
rcu_init_one();
if (dump_tree)
--
2.32.0
next prev parent reply other threads:[~2022-01-13 2:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-11 23:32 [PATCH 0/5] handle kthread_prio kernel cmdline parameter consistently Alison Chaiken
2022-01-11 23:32 ` Alison Chaiken [this message]
2022-01-11 23:32 ` [PATCH 2/4] RCU: make priority of grace-period thread consistent Alison Chaiken
2022-01-11 23:32 ` [PATCH 3/4] RCU: elevate priority of offloaded callback threads Alison Chaiken
2022-01-11 23:32 ` [PATCH 4/4] RCU: update documentation regarding kthread_prio cmdline parameter Alison Chaiken
2022-01-12 1:03 ` [PATCH 0/5] handle kthread_prio kernel cmdline parameter consistently Paul E. McKenney
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