Re: [PATCH 2/2] drivers/base/node: merge unregister_one_node() and unregister_node() to a single function.

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 24/09/2025 à 20:40, Donet Tom a écrit :
> unregister_one_node() and unregister_node() are small functions.
> This patch merges them into a single function named unregister_node()
> to improve code readability.

Same comment than patch 1. It is not only because they are small that 
you merge them, it is primarily because unregister_node() only has one 
caller.

> 
> No functional changes are introduced.
> 
> Signed-off-by: Donet Tom <donettom@linux.ibm.com>
> ---
>   drivers/base/node.c  | 37 +++++++++++++++++--------------------
>   include/linux/node.h |  6 ++----
>   mm/memory_hotplug.c  |  4 ++--
>   3 files changed, 21 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/base/node.c b/drivers/base/node.c
> index eab620e29c78..d460c1675c77 100644
> --- a/drivers/base/node.c
> +++ b/drivers/base/node.c
> @@ -638,23 +638,6 @@ static void node_device_release(struct device *dev)
>   	kfree(to_node(dev));
>   }
>   
> -/**
> - * unregister_node - unregister a node device
> - * @node: node going away
> - *
> - * Unregisters a node device @node.  All the devices on the node must be
> - * unregistered before calling this function.
> - */
> -void unregister_node(struct node *node)
> -{
> -	hugetlb_unregister_node(node);
> -	compaction_unregister_node(node);
> -	reclaim_unregister_node(node);
> -	node_remove_accesses(node);
> -	node_remove_caches(node);
> -	device_unregister(&node->dev);
> -}
> -
>   struct node *node_devices[MAX_NUMNODES];
>   
>   /*
> @@ -887,12 +870,26 @@ int register_node(int nid)
>   	return error;
>   }
>   
> -void unregister_one_node(int nid)
> +/**
> + * unregister_node - unregister a node device
> + * @nid: nid of the node going away
> + *
> + * Unregisters the node device at node id  @nid.  All the devices on the
> + * node must be unregistered before calling this function.
> + */
> +void unregister_node(int nid)
>   {
> -	if (!node_devices[nid])
> +	struct node *node = node_devices[nid];
> +
> +	if (!node)
>   		return;
>   
> -	unregister_node(node_devices[nid]);
> +	hugetlb_unregister_node(node);
> +	compaction_unregister_node(node);
> +	reclaim_unregister_node(node);
> +	node_remove_accesses(node);
> +	node_remove_caches(node);
> +	device_unregister(&node->dev);
>   	node_devices[nid] = NULL;
>   }
>   
> diff --git a/include/linux/node.h b/include/linux/node.h
> index 4dcf876cd0b4..d721127964b3 100644
> --- a/include/linux/node.h
> +++ b/include/linux/node.h
> @@ -124,8 +124,6 @@ static inline void register_memory_blocks_under_nodes(void)
>   }
>   #endif
>   
> -extern void unregister_node(struct node *node);
> -
>   struct node_notify {
>   	int nid;
>   };
> @@ -169,7 +167,7 @@ static inline int hotplug_node_notifier(notifier_fn_t fn, int pri)
>   extern void node_dev_init(void);
>   /* Core of the node registration - only memory hotplug should use this */
>   extern int register_node(int nid);
> -extern void unregister_one_node(int nid);
> +extern void unregister_node(int nid);

No 'extern' on function prototypes.

>   extern int register_cpu_under_node(unsigned int cpu, unsigned int nid);
>   extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid);
>   extern void unregister_memory_block_under_nodes(struct memory_block *mem_blk);
> @@ -185,7 +183,7 @@ static inline int register_node(int nid)
>   {
>   	return 0;
>   }
> -static inline int unregister_one_node(int nid)
> +static inline int unregister_node(int nid)
>   {
>   	return 0;
>   }
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 6c050d867031..94a8f6e8811a 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1596,7 +1596,7 @@ int add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
>   error:
>   	if (new_node) {
>   		node_set_offline(nid);
> -		unregister_one_node(nid);
> +		unregister_node(nid);
>   	}
>   error_memblock_remove:
>   	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
> @@ -2201,7 +2201,7 @@ void try_offline_node(int nid)
>   	 * node now.
>   	 */
>   	node_set_offline(nid);
> -	unregister_one_node(nid);
> +	unregister_node(nid);
>   }
>   EXPORT_SYMBOL(try_offline_node);
>