Re: [PATCH v1 3/5] mm/memory_hotplug: check if sections are already online/offline

[David Hildenbrand]

On 16.08.2018 12:47, Oscar Salvador wrote:
> On Thu, Aug 16, 2018 at 12:06:26PM +0200, David Hildenbrand wrote:
> 
>> +
>> +/* check if all mem sections are offline */
>> +bool mem_sections_offline(unsigned long pfn, unsigned long end_pfn)
>> +{
>> +	for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
>> +		unsigned long section_nr = pfn_to_section_nr(pfn);
>> +
>> +		if (WARN_ON(!valid_section_nr(section_nr)))
>> +			continue;
>> +		if (online_section_nr(section_nr))
>> +			return false;
>> +	}
>> +	return true;
>> +}
> 
> AFAICS pages_correctly_probed will catch this first.
> pages_correctly_probed checks for the section to be:
> 
> - present
> - valid
> - !online

Right, I missed that function.

> 
> Maybe it makes sense to rename it, and write another pages_correctly_probed routine
> for the offline case.
> 
> So all checks would stay in memory_block_action level, and we would not need
> the mem_sections_offline/online stuff.

I guess I would rather have it all moved into
online_pages/offline_pages, so we have a clean interface.

> 
> Thanks
> 


-- 

Thanks,

David / dhildenb