Re: [PATCH] mm/huge_memory: consolidate order-related checks into folio_split_supported()

["David Hildenbrand (Red Hat)" <david@kernel.org>]

On 14.11.25 16:03, Wei Yang wrote:
> On Fri, Nov 14, 2025 at 09:49:34AM +0100, David Hildenbrand (Red Hat) wrote:
>> On 14.11.25 08:57, Wei Yang wrote:
>>> The primary goal of the folio_split_supported() function is to validate
>>> whether a folio is suitable for splitting and to bail out early if it is
>>> not.
>>>
>>> Currently, some order-related checks are scattered throughout the
>>> calling code rather than being centralized in folio_split_supported().
>>>
>>> This commit moves all remaining order-related validation logic into
>>> folio_split_supported(). This consolidation ensures that the function
>>> serves its intended purpose as a single point of failure and improves
>>> the clarity and maintainability of the surrounding code.
>>
>> Combining the EINVAL handling sounds reasonable.
>>
> 
> You mean:
> 
> This commit combines the EINVAL handling logic into folio_split_supported().
> This consolidation ... ?

It was not a suggestion to change, it was rather only a comment from my 
side :)

[...]

>>
>> The mapping_max_folio_order() check is new now. What is the default value of that? Is it always initialized properly?
>>
> 
> Not sure "is new now" means what?
> 
> Original check use mapping_large_folio_support() which calls
> mapping_max_folio_order(). It looks not new to me.

Right, but we did not actually care about the exact value.

IOW, we didn't check for order <= mapping_max_folio_order() before.

SO I'm just curious if that is universally fine.

-- 
Cheers

David