[PATCH 2/5] mm: rmap: add a ZONE_DEVICE folio warning in folio_referenced()

[David Hildenbrand (Arm)]

On 2/24/26 06:49, Baolin Wang wrote:
> 
> 
> On 2/24/26 10:38 AM, Rik van Riel wrote:
>> On Tue, 2026-02-24 at 09:56 +0800, Baolin Wang wrote:
>>>
>>> diff --git a/mm/rmap.c b/mm/rmap.c
>>> index bff8f222004e..be785dfc9336 100644
>>> --- a/mm/rmap.c
>>> +++ b/mm/rmap.c
>>> @@ -1065,6 +1065,7 @@ int folio_referenced(struct folio *folio, int
>>> is_locked,
>>>           .invalid_vma = invalid_folio_referenced_vma,
>>>       };
>>>   +    VM_WARN_ON_FOLIO(folio_is_zone_device(folio), folio);
>>>       *vm_flags = 0;
>>>       if (!pra.mapcount)
>>>           return 0;
>>
>> Should be a VM_WARN_ON_ONCE_FOLIO so we do not cause
>> a softlockup if we try to print information about a
>> million ZONE_DEVICE pages?
> 
> Yes, sounds reasonable. Will do in next version. Thanks for reviewing.

Feel free to add my

Acked-by: David Hildenbrand (Arm) <david at kernel.org>

to that.

-- 
Cheers,

David