Re: [PATCH 1/2] drivers/base/node: merge register_one_node() and register_node() to a single function.

Christophe Leroy
2025-09-24T19:50:40Z

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

This is unclear.

What it really does is it folds register_node() into its only caller
which is register_one_node() and then it renames register_one_node()
into register_node().

>
> No functional changes are introduced.
>
> Signed-off-by: Donet Tom <donettom@linux.ibm.com>
> ---
> arch/powerpc/platforms/pseries/pci_dlpar.c | 2 +-
> arch/x86/mm/numa.c | 4 +-
> drivers/base/node.c | 52 +++++++++-------------
> include/linux/node.h | 4 +-
> mm/memory_hotplug.c | 4 +-
> mm/mm_init.c | 2 +-
> 6 files changed, 28 insertions(+), 40 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/pci_dlpar.c b/arch/powerpc/platforms/pseries/pci_dlpar.c
> index aeb8633a3d00..8c77ec7980de 100644
> --- a/arch/powerpc/platforms/pseries/pci_dlpar.c
> +++ b/arch/powerpc/platforms/pseries/pci_dlpar.c
> @@ -29,7 +29,7 @@ struct pci_controller *init_phb_dynamic(struct device_node *dn)
> nid = of_node_to_nid(dn);
> if (likely((nid) >= 0)) {
> if (!node_online(nid)) {
> - if (register_one_node(nid)) {
> + if (register_node(nid)) {
> pr_err("PCI: Failed to register node %d\n", nid);
> } else {
> update_numa_distance(dn);
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index c24890c40138..7a97327140df 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -262,7 +262,7 @@ void __init init_gi_nodes(void)
> * bringup_nonboot_cpus
> * cpu_up
> * __try_online_node
> - * register_one_node
> + * register_node
> * because node_subsys is not initialized yet.
> * TODO remove dependency on node_online
> */
> @@ -303,7 +303,7 @@ void __init init_cpu_to_node(void)
> * bringup_nonboot_cpus
> * cpu_up
> * __try_online_node
> - * register_one_node
> + * register_node
> * because node_subsys is not initialized yet.
> * TODO remove dependency on node_online
> */
> diff --git a/drivers/base/node.c b/drivers/base/node.c
> index 6b6e55a98b79..eab620e29c78 100644
> --- a/drivers/base/node.c
> +++ b/drivers/base/node.c
> @@ -638,33 +638,6 @@ static void node_device_release(struct device *dev)
> kfree(to_node(dev));
> }
>
> -/*
> - * register_node - Setup a sysfs device for a node.
> - * @num - Node number to use when creating the device.
> - *
> - * Initialize and register the node device.
> - */
> -static int register_node(struct node *node, int num)
> -{
> - int error;
> -
> - node->dev.id = num;
> - node->dev.bus = &node_subsys;
> - node->dev.release = node_device_release;
> - node->dev.groups = node_dev_groups;
> - error = device_register(&node->dev);
> -
> - if (error) {
> - put_device(&node->dev);
> - } else {
> - hugetlb_register_node(node);
> - compaction_register_node(node);
> - reclaim_register_node(node);
> - }
> -
> - return error;
> -}
> -
> /**
> * unregister_node - unregister a node device
> * @node: node going away
> @@ -869,7 +842,13 @@ void register_memory_blocks_under_node_hotplug(int nid, unsigned long start_pfn,
> }
> #endif /* CONFIG_MEMORY_HOTPLUG */
>
> -int register_one_node(int nid)
> +/*
> + * register_node - Setup a sysfs device for a node.
> + * @nid - Node number to use when creating the device.
> + *
> + * Initialize and register the node device.
> + */
> +int register_node(int nid)
> {
> int error;
> int cpu;
> @@ -880,14 +859,23 @@ int register_one_node(int nid)
> return -ENOMEM;
>
> INIT_LIST_HEAD(&node->access_list);
> - node_devices[nid] = node;
>
> - error = register_node(node_devices[nid], nid);
> + node->dev.id = nid;
> + node->dev.bus = &node_subsys;
> + node->dev.release = node_device_release;
> + node->dev.groups = node_dev_groups;
> +
> + error = device_register(&node->dev);
> if (error) {
> - node_devices[nid] = NULL;
> + put_device(&node->dev);
> return error;
> }
>
> + node_devices[nid] = node;
> + hugetlb_register_node(node);
> + compaction_register_node(node);
> + reclaim_register_node(node);
> +
> /* link cpu under this node */
> for_each_present_cpu(cpu) {
> if (cpu_to_node(cpu) == nid)
> @@ -980,7 +968,7 @@ void __init node_dev_init(void)
> * to already created cpu devices.
> */
> for_each_online_node(i) {
> - ret = register_one_node(i);
> + ret = register_node(i);
> if (ret)
> panic("%s() failed to add node: %d\n", __func__, ret);
> }
> diff --git a/include/linux/node.h b/include/linux/node.h
> index 2c7529335b21..4dcf876cd0b4 100644
> --- a/include/linux/node.h
> +++ b/include/linux/node.h
> @@ -168,7 +168,7 @@ static inline int hotplug_node_notifier(notifier_fn_t fn, int pri)
> #ifdef CONFIG_NUMA
> extern void node_dev_init(void);
> /* Core of the node registration - only memory hotplug should use this */
> -extern int register_one_node(int nid);
> +extern int register_node(int nid);

extern keyword is pointless on functions prototypes.

checkpatch.pl usually complains about that.

I know previous prototype was extern and all surrounding also are, but
it is not because mistakes were done in the past that you have to
continue doing the same mistakes.

> extern void unregister_one_node(int nid);
> extern int register_cpu_under_node(unsigned int cpu, unsigned int nid);
> extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid);
> @@ -181,7 +181,7 @@ extern int register_memory_node_under_compute_node(unsigned int mem_nid,
> static inline void node_dev_init(void)
> {
> }
> -static inline int register_one_node(int nid)
> +static inline int register_node(int nid)
> {
> return 0;
> }
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 0be83039c3b5..6c050d867031 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1311,7 +1311,7 @@ static int __try_online_node(int nid, bool set_node_online)
>
> if (set_node_online) {
> node_set_online(nid);
> - ret = register_one_node(nid);
> + ret = register_node(nid);
> BUG_ON(ret);
> }
> out:
> @@ -1542,7 +1542,7 @@ int add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
> goto error_memblock_remove;
> if (ret) {
> node_set_online(nid);
> - ret = register_one_node(nid);
> + ret = register_node(nid);
> if (WARN_ON(ret)) {
> node_set_offline(nid);
> goto error_memblock_remove;
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index df614556741a..e1a19a3dadd7 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -1909,7 +1909,7 @@ void __init free_area_init(unsigned long *max_zone_pfn)
> free_area_init_node(nid);
>
> /*
> - * No sysfs hierarchy will be created via register_one_node()
> + * No sysfs hierarchy will be created via register_node()
> *for memory-less node because here it's not marked as N_MEMORY
> *and won't be set online later. The benefit is userspace
> *program won't be confused by sysfs files/directories of