[PATCH v3 1/5] mm: Optimize mprotect() by batch-skipping PTEs

[Dev Jain]

On 22/05/25 12:43 pm, David Hildenbrand wrote:
>
>>> ... likely with a better function name,
>>
>>
>> I want to be able to reuse the folio from vm_normal_folio(), and we also
>> need
>>
>> nr_ptes to know how much to skip, so if there is no objection in passing
>> int *nr_ptes,
>>
>> or struct folio **foliop to this new function, then I'll carry on with
>> your suggestion :)
>
> Can you quickly prototype what you have in mind and paste it here? 
> Will make it easier :)


if (prot_numa)

     func(vma, addr, oldpte, &nr);


struct folio *folio func(vma, addr, oldpte, int *nr)

{

     if (pte_protnone(oldpte))

         *nr = 1, return NULL;

     folio = vm_normal_folio();

     if (!folio)

         *nr =1, return NULL;

     if the other skipping conditions happen, goto skip_batch, return 
folio and set *nr = batch


     if (sysctl.....) {

skip_batch:

     *nr = mprotect_batch();

}

     if (folio_use_access_time)....

     return folio;

}