Re: [PATCH v4] mm: introduce a new page type for page pool in page type

[David Hildenbrand (Arm)]

On 5/13/26 15:26, Byungchul Park wrote:
> On Wed, May 13, 2026 at 03:02:43PM +0200, David Hildenbrand (Arm) wrote:
>> On 5/13/26 14:39, Byungchul Park wrote:
>>>  On 5/13/26 14:18, Byungchul Park wrote:
>>>
>>> This is not final patch, but for sharing the rough idea *with code* -
>>> maybe there are more points in code that should be adjusted by the
>>> change.  I just typed the draft patch quick just for sharing idea.
>>>
>>> If we should allow pp type pages to be used in mapping as well, then
>>> we should allow a page to keep both its type and mapcount at the same
>>> time.  Am I missing something?
>>
>> We don't want code to accidentally overflow mapcounts into these bits and have
>> them wrongly be detected as page types.
>>
>> This is just very fragile.
> 
> Okay.  Thanks for the explanation.  Plus, the adjustment I mentioned
> might not be as simple as I thought it'd be.
> 
> So sorry about the noise.  I'm a zombie now.  I'll think about it after
> some rest.

It's a shame we didn't get reports earlier that we do have some vm_insert_page()
users :(

-- 
Cheers,

David