Re: [PATCH rfc 2/9] mm: migrate_device: use more folio in __migrate_device_pages()

[Kefeng Wang <wangkefeng.wang@huawei.com>]

On 2024/2/2 3:27, Matthew Wilcox wrote:
> On Mon, Jan 29, 2024 at 03:09:27PM +0800, Kefeng Wang wrote:
>> Use newfolio/folio for migrate_folio_extra()/migrate_folio() to
>> save three compound_head() calls.
> 
> I've looked at this function before and I get stuck on the question of
> whether a device page truly is a folio or not.  I think for the moment,
> we've decided that it is, so ..
> 
> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> 
> Although ...
> 
>> @@ -729,13 +730,12 @@ static void __migrate_device_pages(unsigned long *src_pfns,
>>   		}
>>   
>>   		mapping = page_mapping(page);
>> +		folio = page_folio(page);
>> +		newfolio = page_folio(newpage);
> 
> you should save one more call to compound_head() by changing the
> page_mapping() to folio_mapping().

Missing this one, will update, thanks.
>