Re: [PATCH v2 2/2] driver/base: Remove unused functions

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

On 5/1/25 8:38 PM, Zi Yan wrote:
> On 28 Apr 2025, at 13:03, Donet Tom wrote:
>
>> The functions register_mem_block_under_node_early and get_nid_for_pfn
>> are not used, as register_memory_blocks_under_node_early is now used
>> to register memory blocks during early boot. Therefore, these unused
>> functions have been removed.
>>
>> Signed-off-by: Donet Tom <donettom@linux.ibm.com>
>> ---
>>   drivers/base/node.c | 54 +--------------------------------------------
>>   1 file changed, 1 insertion(+), 53 deletions(-)
>>
>> diff --git a/drivers/base/node.c b/drivers/base/node.c
>> index 4869333d366d..59ec507fc97d 100644
>> --- a/drivers/base/node.c
>> +++ b/drivers/base/node.c
>> @@ -748,15 +748,6 @@ int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
>>   }
>>
>>   #ifdef CONFIG_MEMORY_HOTPLUG
>> -static int __ref get_nid_for_pfn(unsigned long pfn)
>> -{
>> -#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
>> -	if (system_state < SYSTEM_RUNNING)
>> -		return early_pfn_to_nid(pfn);
>> -#endif
>> -	return pfn_to_nid(pfn);
>> -}
>> -
>>   static void do_register_memory_block_under_node(int nid,
>>   						struct memory_block *mem_blk,
>>   						enum meminit_context context)
>> @@ -783,46 +774,6 @@ static void do_register_memory_block_under_node(int nid,
>>   				    ret);
>>   }
>>
>> -/* register memory section under specified node if it spans that node */
>> -static int register_mem_block_under_node_early(struct memory_block *mem_blk,
>> -					       void *arg)
>> -{
>> -	unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
>> -	unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
>> -	unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
>> -	int nid = *(int *)arg;
>> -	unsigned long pfn;
>> -
>> -	for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
>> -		int page_nid;
>> -
>> -		/*
>> -		 * memory block could have several absent sections from start.
>> -		 * skip pfn range from absent section
>> -		 */
>> -		if (!pfn_in_present_section(pfn)) {
>> -			pfn = round_down(pfn + PAGES_PER_SECTION,
>> -					 PAGES_PER_SECTION) - 1;
>> -			continue;
>> -		}
>> -
>> -		/*
>> -		 * We need to check if page belongs to nid only at the boot
>> -		 * case because node's ranges can be interleaved.
>> -		 */
>> -		page_nid = get_nid_for_pfn(pfn);
>> -		if (page_nid < 0)
>> -			continue;
>> -		if (page_nid != nid)
>> -			continue;
>> -
>> -		do_register_memory_block_under_node(nid, mem_blk, MEMINIT_EARLY);
>> -		return 0;
>> -	}
>> -	/* mem section does not span the specified node */
>> -	return 0;
>> -}
>> -
>>   /*
>>    * During hotplug we know that all pages in the memory block belong to the same
>>    * node.
>> @@ -895,10 +846,7 @@ void register_memory_blocks_under_node(int nid, unsigned long start_pfn,
>>   {
> Should this function be renamed to register_memory_blocks_under_node_hotplug
> to reflect its current implementation?

Yes, we can rename it since it will only be called during hotplug. I will add it in next version.

Thanks
Donet


>
>>   	walk_memory_blocks_func_t func;
>>
>> -	if (context == MEMINIT_HOTPLUG)
>> -		func = register_mem_block_under_node_hotplug;
>> -	else
>> -		func = register_mem_block_under_node_early;
>> +	func = register_mem_block_under_node_hotplug;
>>
>>   	walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
>>   			   (void *)&nid, func);
>> -- 
>> 2.48.1
>
> --
> Best Regards,
> Yan, Zi
>