Re: [PATCH -next 3/8] rcu/nocb: Remove unnecessary WakeOvfIsDeferred wake path

[Boqun Feng <boqun.feng@gmail.com>]

On Thu, Jan 08, 2026 at 08:39:11PM -0500, Joel Fernandes wrote:
> On Thu, Jan 08, 2026 at 04:57:26PM +0100, Frederic Weisbecker wrote:
> > Le Thu, Jan 01, 2026 at 11:34:12AM -0500, Joel Fernandes a écrit :
> > > @@ -974,8 +959,7 @@ static bool do_nocb_deferred_wakeup_common(struct rcu_data *rdp_gp,
> > >  		return false;
> > >  	}
> > >  
> > > -	ndw = rdp_gp->nocb_defer_wakeup;
> > > -	ret = __wake_nocb_gp(rdp_gp, rdp, ndw == RCU_NOCB_WAKE_FORCE, flags);
> > > +	ret = __wake_nocb_gp(rdp_gp, rdp, false, flags);
> > 
> > The force parameter can now be removed, right? (same applies to wake_nocb_gp()).
> > 
> > Other than that:
> > 
> > Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
> 
> Ah true! Thanks, so the following hunk needs to be squashed into the patch
> then, with the review tag. Boqun, if you want to do that please do, or I can
> send it again for the next merge window.
> 

We still have time for this merge window, but I see there is still
reviewing going on for other patches, maybe you could resend these 3
patches once we reach agreement, and then we can decide which merge
window. Thoughts?

Regards,
Boqun

> ---8<-----------------------
> 
> From: "Joel Fernandes" <joelagnelf@nvidia.com>
> Subject: [PATCH] fixup! rcu/nocb: Remove unnecessary WakeOvfIsDeferred wake
>  path
> 
> Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
> ---
>  kernel/rcu/tree.c      |  2 +-
>  kernel/rcu/tree.h      |  2 +-
>  kernel/rcu/tree_nocb.h | 14 +++++++-------
>  3 files changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index 293bbd9ac3f4..2921ffb19939 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -3769,7 +3769,7 @@ static void rcu_barrier_entrain(struct rcu_data *rdp)
>  	}
>  	rcu_nocb_unlock(rdp);
>  	if (wake_nocb)
> -		wake_nocb_gp(rdp, false);
> +		wake_nocb_gp(rdp);
>  	smp_store_release(&rdp->barrier_seq_snap, gseq);
>  }
>  
> diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
> index 653fb4ba5852..7dfc57e9adb1 100644
> --- a/kernel/rcu/tree.h
> +++ b/kernel/rcu/tree.h
> @@ -499,7 +499,7 @@ static void zero_cpu_stall_ticks(struct rcu_data *rdp);
>  static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp);
>  static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq);
>  static void rcu_init_one_nocb(struct rcu_node *rnp);
> -static bool wake_nocb_gp(struct rcu_data *rdp, bool force);
> +static bool wake_nocb_gp(struct rcu_data *rdp);
>  static bool rcu_nocb_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp,
>  				  unsigned long j, bool lazy);
>  static void call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *head,
> diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
> index daff2756cd90..c6f1ddecc2d8 100644
> --- a/kernel/rcu/tree_nocb.h
> +++ b/kernel/rcu/tree_nocb.h
> @@ -192,7 +192,7 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
>  
>  static bool __wake_nocb_gp(struct rcu_data *rdp_gp,
>  			   struct rcu_data *rdp,
> -			   bool force, unsigned long flags)
> +			   unsigned long flags)
>  	__releases(rdp_gp->nocb_gp_lock)
>  {
>  	bool needwake = false;
> @@ -225,13 +225,13 @@ static bool __wake_nocb_gp(struct rcu_data *rdp_gp,
>  /*
>   * Kick the GP kthread for this NOCB group.
>   */
> -static bool wake_nocb_gp(struct rcu_data *rdp, bool force)
> +static bool wake_nocb_gp(struct rcu_data *rdp)
>  {
>  	unsigned long flags;
>  	struct rcu_data *rdp_gp = rdp->nocb_gp_rdp;
>  
>  	raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags);
> -	return __wake_nocb_gp(rdp_gp, rdp, force, flags);
> +	return __wake_nocb_gp(rdp_gp, rdp, flags);
>  }
>  
>  #ifdef CONFIG_RCU_LAZY
> @@ -553,7 +553,7 @@ static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_alldone,
>  					   TPS("WakeLazy"));
>  		} else if (!irqs_disabled_flags(flags)) {
>  			/* ... if queue was empty ... */
> -			wake_nocb_gp(rdp, false);
> +			wake_nocb_gp(rdp);
>  			trace_rcu_nocb_wake(rcu_state.name, rdp->cpu,
>  					    TPS("WakeEmpty"));
>  		} else {
> @@ -959,7 +959,7 @@ static bool do_nocb_deferred_wakeup_common(struct rcu_data *rdp_gp,
>  		return false;
>  	}
>  
> -	ret = __wake_nocb_gp(rdp_gp, rdp, false, flags);
> +	ret = __wake_nocb_gp(rdp_gp, rdp, flags);
>  	trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("DeferredWake"));
>  
>  	return ret;
> @@ -1255,7 +1255,7 @@ lazy_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
>  		}
>  		rcu_nocb_try_flush_bypass(rdp, jiffies);
>  		rcu_nocb_unlock_irqrestore(rdp, flags);
> -		wake_nocb_gp(rdp, false);
> +		wake_nocb_gp(rdp);
>  		sc->nr_to_scan -= _count;
>  		count += _count;
>  		if (sc->nr_to_scan <= 0)
> @@ -1640,7 +1640,7 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
>  {
>  }
>  
> -static bool wake_nocb_gp(struct rcu_data *rdp, bool force)
> +static bool wake_nocb_gp(struct rcu_data *rdp)
>  {
>  	return false;
>  }
> -- 
> 2.34.1
>