Re: [PATCH v4 3/4] Remove register_memory_blocks_under_node() function call from register_one_node

[Donet Tom <donettom@linux.ibm.com>]

On 5/16/25 2:48 PM, David Hildenbrand wrote:
> On 16.05.25 10:19, Donet Tom wrote:
>> register_one_node() is now only called via cpu_up() → 
>> __try_online_node()
>> during CPU hotplug operations to online a node. At this stage, the 
>> node has
>> not yet had any memory added. As a result, there are no memory blocks to
>> walk or register, so calling register_memory_blocks_under_node() is
>> unnecessary. Therefore, the call to register_memory_blocks_under_node()
>> has been removed from register_one_node().
>
> It might help to throw in some empty lines to make this easier to read.
>
> Patch subject should start with something like
>
> "node:" or "mm:"


Sorry. I missed it. I will add it in the next version.


>
>>
>> Signed-off-by: Donet Tom <donettom@linux.ibm.com>
>>
>> ---
>> v3->v4
>>
>> Addressed Mike's comment by dropping the call to
>> register_memory_blocks_under_node() from register_one_node()
>>
>> v3 - 
>> https://lore.kernel.org/all/b49ed289096643ff5b5fbedcf1d1c1be42845a74.1746250339.git.donettom@linux.ibm.com/
>> v2 - 
>> https://lore.kernel.org/all/fbe1e0c7d91bf3fa9a64ff5d84b53ded1d0d5ac7.1745852397.git.donettom@linux.ibm.com/
>> v1 - 
>> https://lore.kernel.org/all/50142a29010463f436dc5c4feb540e5de3bb09df.1744175097.git.donettom@linux.ibm.com/
>> ---
>>   include/linux/node.h | 6 ------
>>   1 file changed, 6 deletions(-)
>>
>> diff --git a/include/linux/node.h b/include/linux/node.h
>> index 806e62638cbe..8b8f96ca5b06 100644
>> --- a/include/linux/node.h
>> +++ b/include/linux/node.h
>> @@ -137,15 +137,9 @@ static inline int register_one_node(int nid)
>>       int error = 0;
>>         if (node_online(nid)) {
>> -        struct pglist_data *pgdat = NODE_DATA(nid);
>> -        unsigned long start_pfn = pgdat->node_start_pfn;
>> -        unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
>> -
>>           error = __register_one_node(nid);
>>           if (error)
>>               return error;
>> -        register_memory_blocks_under_node(nid, start_pfn, end_pfn,
>> -                          MEMINIT_EARLY);
>>       }
>
> Can be further simplified
>
> if (node_online(nid))
>     error = __register_one_node(nid);
> return error;


Thanks. I will add it and it in the next version.


>
>>         return error;
>
>