The pattern of checking nocb_defer_wakeup and deleting the timer is
duplicated in __wake_nocb_gp() and nocb_gp_wait(). Extract this into a
common helper function nocb_defer_wakeup_cancel().

This removes code duplication and makes it easier to maintain.

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
 kernel/rcu/tree_nocb.h | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index 64a8ff350f92..b3337c7231cc 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -190,6 +190,15 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
 	init_swait_queue_head(&rnp->nocb_gp_wq[1]);
 }
 
+/* Clear any pending deferred wakeup timer (nocb_gp_lock must be held). */
+static void nocb_defer_wakeup_cancel(struct rcu_data *rdp_gp)
+{
+	if (rdp_gp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) {
+		WRITE_ONCE(rdp_gp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
+		timer_delete(&rdp_gp->nocb_timer);
+	}
+}
+
 static bool __wake_nocb_gp(struct rcu_data *rdp_gp,
 			   struct rcu_data *rdp,
 			   unsigned long flags)
@@ -204,10 +213,7 @@ static bool __wake_nocb_gp(struct rcu_data *rdp_gp,
 		return false;
 	}
 
-	if (rdp_gp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) {
-		WRITE_ONCE(rdp_gp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
-		timer_delete(&rdp_gp->nocb_timer);
-	}
+	nocb_defer_wakeup_cancel(rdp_gp);
 
 	if (READ_ONCE(rdp_gp->nocb_gp_sleep)) {
 		WRITE_ONCE(rdp_gp->nocb_gp_sleep, false);
@@ -788,10 +794,7 @@ static void nocb_gp_wait(struct rcu_data *my_rdp)
 		if (rdp_toggling)
 			my_rdp->nocb_toggling_rdp = NULL;
 
-		if (my_rdp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) {
-			WRITE_ONCE(my_rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
-			timer_delete(&my_rdp->nocb_timer);
-		}
+		nocb_defer_wakeup_cancel(my_rdp);
 		WRITE_ONCE(my_rdp->nocb_gp_sleep, true);
 		raw_spin_unlock_irqrestore(&my_rdp->nocb_gp_lock, flags);
 	} else {
-- 
2.34.1

On Mon, Jan 19, 2026 at 06:12:23PM -0500, Joel Fernandes wrote:
> The pattern of checking nocb_defer_wakeup and deleting the timer is
> duplicated in __wake_nocb_gp() and nocb_gp_wait(). Extract this into a
> common helper function nocb_defer_wakeup_cancel().
> 
> This removes code duplication and makes it easier to maintain.
> 
> Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
> Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>

Good eyes!

Reviewed-by: Paul E. McKenney <paulmck@kernel.org>

> ---
>  kernel/rcu/tree_nocb.h | 19 +++++++++++--------
>  1 file changed, 11 insertions(+), 8 deletions(-)
> 
> diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
> index 64a8ff350f92..b3337c7231cc 100644
> --- a/kernel/rcu/tree_nocb.h
> +++ b/kernel/rcu/tree_nocb.h
> @@ -190,6 +190,15 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
>  	init_swait_queue_head(&rnp->nocb_gp_wq[1]);
>  }
>  
> +/* Clear any pending deferred wakeup timer (nocb_gp_lock must be held). */
> +static void nocb_defer_wakeup_cancel(struct rcu_data *rdp_gp)
> +{
> +	if (rdp_gp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) {
> +		WRITE_ONCE(rdp_gp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
> +		timer_delete(&rdp_gp->nocb_timer);
> +	}
> +}
> +
>  static bool __wake_nocb_gp(struct rcu_data *rdp_gp,
>  			   struct rcu_data *rdp,
>  			   unsigned long flags)
> @@ -204,10 +213,7 @@ static bool __wake_nocb_gp(struct rcu_data *rdp_gp,
>  		return false;
>  	}
>  
> -	if (rdp_gp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) {
> -		WRITE_ONCE(rdp_gp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
> -		timer_delete(&rdp_gp->nocb_timer);
> -	}
> +	nocb_defer_wakeup_cancel(rdp_gp);
>  
>  	if (READ_ONCE(rdp_gp->nocb_gp_sleep)) {
>  		WRITE_ONCE(rdp_gp->nocb_gp_sleep, false);
> @@ -788,10 +794,7 @@ static void nocb_gp_wait(struct rcu_data *my_rdp)
>  		if (rdp_toggling)
>  			my_rdp->nocb_toggling_rdp = NULL;
>  
> -		if (my_rdp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) {
> -			WRITE_ONCE(my_rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
> -			timer_delete(&my_rdp->nocb_timer);
> -		}
> +		nocb_defer_wakeup_cancel(my_rdp);
>  		WRITE_ONCE(my_rdp->nocb_gp_sleep, true);
>  		raw_spin_unlock_irqrestore(&my_rdp->nocb_gp_lock, flags);
>  	} else {
> -- 
> 2.34.1
>