Re: [PATCH mm-new v3 1/1] mm/khugepaged: abort collapse scan on non-swap entries

[Lance Yang <lance.yang@linux.dev>]

On 2025/10/14 22:32, David Hildenbrand wrote:
> 
>> static inline int pte_protnone(pte_t pte)
>> {
>>     return (pte_flags(pte) & (_PAGE_PROTNONE | _PAGE_PRESENT))
>>         == _PAGE_PROTNONE;
>> }
>>
>> static inline int pte_present(pte_t a)
>> {
>>     return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE);
>> }
>> ```
>>
>> On x86, pte_present() returns true for a protnone pte. And I'd assume
>> other archs behave similarly ...
> 
> Applies to all architecture. prot-none entries must be present, 
> otherwise we'd have a lot of other issues :)

Thanks for confirming, David! That's good to know ;p

So @Lorenzo, looks like we're good here on the protnone front. Does
that clear up your concern?