Re: [PATCH v7 1/3] mm/madvise: introduce clear_young_dirty_ptes() batch helper

[Lance Yang]

On Wed, Apr 17, 2024 at 4:19 PM David Hildenbrand <david@xxxxxxxxxx> wrote:
>
> On 17.04.24 07:04, Lance Yang wrote:
> > Hey David, Ryan,
> >
> > How about this change?
> >
> > static inline void clear_young_dirty_ptes(struct vm_area_struct *vma,
> >                                         unsigned long addr, pte_t *ptep,
> >                                         unsigned int nr, cydp_t flags)
> > {
> >       if (flags == CYDP_CLEAR_YOUNG) {
> >               for (;;) {
> >                       ptep_test_and_clear_young(vma, addr, ptep);
> >                       if (--nr == 0)
> >                               break;
> >                       ptep++;
> >                       addr += PAGE_SIZE;
> >               }
> >               return;
> >       }
> >
> >       pte_t pte;
> >
> >       for (;;) {
> >               pte = ptep_get_and_clear(vma->vm_mm, addr, ptep);
> >
> >               if (flags & CYDP_CLEAR_YOUNG)
> >                       pte = pte_mkold(pte);
> >               if (flags & CYDP_CLEAR_DIRTY)
> >                       pte = pte_mkclean(pte);
> >
> >               if (--nr == 0)
> >                       break;
> >               ptep++;
> >               addr += PAGE_SIZE;
> >       }
> > }
>
> Likely it might be best to just KIS for now and leave it as is. The
> compiler should optimize out based on flags already, that's what I ignored.

Got it. Let's keep it as is for now :)

Thanks,
Lance

>
> --
> Cheers,
>
> David / dhildenb
>