1 files changed, 18 insertions, 15 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index a60616e69b66..ff98233d4aa5 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3511,7 +3511,7 @@ static int krc_count(struct kfree_rcu_cpu *krcp)
 }
 
 static void
-schedule_delayed_monitor_work(struct kfree_rcu_cpu *krcp)
+__schedule_delayed_monitor_work(struct kfree_rcu_cpu *krcp)
 {
 	long delay, delay_left;
 
@@ -3526,6 +3526,16 @@ schedule_delayed_monitor_work(struct kfree_rcu_cpu *krcp)
 }
 
 static void
+schedule_delayed_monitor_work(struct kfree_rcu_cpu *krcp)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&krcp->lock, flags);
+	__schedule_delayed_monitor_work(krcp);
+	raw_spin_unlock_irqrestore(&krcp->lock, flags);
+}
+
+static void
 kvfree_rcu_drain_ready(struct kfree_rcu_cpu *krcp)
 {
 	struct list_head bulk_ready[FREE_N_CHANNELS];
@@ -3607,11 +3617,12 @@ kvfree_rcu_queue_batch(struct kfree_rcu_cpu *krcp)
 			}
 
 			// One work is per one batch, so there are three
-			// "free channels", the batch can handle. It can
-			// be that the work is in the pending state when
-			// channels have been detached following by each
-			// other.
+			// "free channels", the batch can handle. Break
+			// the loop since it is done with this CPU thus
+			// queuing an RCU work is _always_ success here.
 			queued = queue_rcu_work(system_unbound_wq, &krwp->rcu_work);
+			WARN_ON_ONCE(!queued);
+			break;
 		}
 	}
 
@@ -3835,7 +3846,7 @@ void kvfree_call_rcu(struct rcu_head *head, void *ptr)
 
 	// Set timer to drain after KFREE_DRAIN_JIFFIES.
 	if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING)
-		schedule_delayed_monitor_work(krcp);
+		__schedule_delayed_monitor_work(krcp);
 
 unlock_return:
 	krc_this_cpu_unlock(krcp, flags);
@@ -4193,7 +4204,6 @@ static void start_poll_synchronize_rcu_common(void)
 	struct rcu_data *rdp;
 	struct rcu_node *rnp;
 
-	lockdep_assert_irqs_enabled();
 	local_irq_save(flags);
 	rdp = this_cpu_ptr(&rcu_data);
 	rnp = rdp->mynode;
@@ -4218,9 +4228,6 @@ static void start_poll_synchronize_rcu_common(void)
  * grace period has elapsed in the meantime.  If the needed grace period
  * is not already slated to start, notifies RCU core of the need for that
  * grace period.
- *
- * Interrupts must be enabled for the case where it is necessary to awaken
- * the grace-period kthread.
  */
 unsigned long start_poll_synchronize_rcu(void)
 {
@@ -4241,9 +4248,6 @@ EXPORT_SYMBOL_GPL(start_poll_synchronize_rcu);
  * grace period (whether normal or expedited) has elapsed in the meantime.
  * If the needed grace period is not already slated to start, notifies
  * RCU core of the need for that grace period.
- *
- * Interrupts must be enabled for the case where it is necessary to awaken
- * the grace-period kthread.
  */
 void start_poll_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp)
 {
@@ -5579,8 +5583,7 @@ void rcu_init_geometry(void)
 	 * Complain and fall back to the compile-time values if this
 	 * limit is exceeded.
 	 */
-	if (rcu_fanout_leaf < 2 ||
-	    rcu_fanout_leaf > sizeof(unsigned long) * 8) {
+	if (rcu_fanout_leaf < 2 || rcu_fanout_leaf > BITS_PER_LONG) {
 		rcu_fanout_leaf = RCU_FANOUT_LEAF;
 		WARN_ON(1);
 		return;