On 9/25/25 2:24 PM, David Hildenbrand wrote:

On 24.09.25 20:40, Donet Tom wrote:

quoted

register_one_node() and register_node() are small functions.
This patch merges them into a single function named register_node()
to improve code readability.

No functional changes are introduced.

Signed-off-by: Donet Tom <redacted>
---

[...]

quoted

  /**
   * 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)
+/*

We can directly convert this to proper kernel doc by using /**

Sure I will add it.

quoted

+ * register_node - Setup a sysfs device for a node.
+ * @nid - Node number to use when creating the device.
+ *
+ * Initialize and register the node device.

and briefly describing what the return value means

"Returns 0 on success, ..."

Sure

quoted

+ */
+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;

Wondering why we did have this temporary setting of the node_devices[] 
in there. But I cannot immediately spot why it was required.

node_devices[] is used in many places to access node data.

In the previous code, immediately after allocating the node

structure, it was stored in node_devices[]. On error paths, we

were clearing the node structure entry from node_devices[].


With the new code, the node structure is now stored in node_devices[]

only after the device has been registered, and just before calling

register_cpu_under_node(), since node_devices[] is accessed inside

that function.


It is also used outside of node.c, in hugetlb_register_all_nodes() .

Do you think we could use a different mechanism instead of this?