Re: [PATCH 4/4] mm: hugetlb: allocate frozen pages in alloc_gigantic_folio()

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

On 2025/9/11 16:25, David Hildenbrand wrote:
> On 11.09.25 08:56, Kefeng Wang wrote:
>> The alloc_gigantic_folio() allocates a folio by alloc_contig_range()
>> with refcount increated and then freeze it, convert to allocate a frozen
>> folio directly to remove the atomic operation about folio refcount, also
>> saving atomic operation during __update_and_free_hugetlb_folio too.
>>
>> Rename some functions to make them more self-explanatory,
>>
>>    folio_alloc_gigantic            -> folio_alloc_frozen_gigantic
>>    cma_{alloc,free}_folio          -> cma_{alloc,free}_frozen_folio
>>    hugetlb_cma_{alloc,free}_folio  -> hugetlb_cma_{alloc,free} 
>> _frozen_folio
> 
> Can we just get rid of folio_alloc_frozen_gigantic?
> 

OK, we could kill it.

> Further, can we just get rid of cma_{alloc,free}_frozen_folio() as well 
> and just let hugetlb use alloc_contig_range_frozen() etc?

HugeTLB can allocate folio by alloc_contig_frozen_pages() directly, but
it could allocate from hugetlb_cma, cma_alloc_folio() need change some
cma metadata, so we need to keep it.

> 
> Long term alloc_contig_range() should just return frozen pages.
> 

Yes, Matthew mention this too, this is the reason for the new version.

Thanks