Subject: Re: [net-next 03/14] lib: cpu_rmap: Add irq_cpu_rmap_remove to complement irq_cpu_rmap_add

From: Jakub Kicinski <[email-masked]>
Date: Tue, 21 Mar 2023 20:46:31 -0700

On Mon, 20 Mar 2023 10:51:33 -0700 Saeed Mahameed wrote:
> From: Eli Cohen <[email-masked]>
> 
> Add a function to complement irq_cpu_rmap_add(). It removes the irq from
> the reverse mapping by setting the notifier to NULL.

Poor commit message. You should mention that glue is released and
cleared via the kref.

BTW who can hold the kref? What are the chances that user will call:

	irq_cpu_rmap_remove()
	irq_cpu_rmap_add()

and the latter will fail because glue was held?

> diff --git a/include/linux/cpu_rmap.h b/include/linux/cpu_rmap.h
> index 0ec745e6cd36..58284f1f3a58 100644
> --- a/include/linux/cpu_rmap.h
> +++ b/include/linux/cpu_rmap.h
> @@ -60,6 +60,8 @@ static inline struct cpu_rmap *alloc_irq_cpu_rmap(unsigned int size)
>  }
>  extern void free_irq_cpu_rmap(struct cpu_rmap *rmap);
>  
> +extern int irq_cpu_rmap_remove(struct cpu_rmap *rmap, int irq);
>  extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
>  
> +

use checkpatch, please :(