Re: [PATCH v5 34/38] mm: eliminate VMA_SPECIAL_FLAGS check in lru_gen_look_around()

[Lorenzo Stoakes (ARM)]

On Mon, Oct 12, 2026 at 08:50:09PM +0200, David Hildenbrand (Arm) wrote:
> On 10/9/26 20:04, Lorenzo Stoakes (ARM) wrote:

> > diff --git a/mm/vmscan.c b/mm/vmscan.c
> > index 3b318efa2916..7adffe8182b3 100644
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -4418,8 +4418,8 @@ bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw, unsigned int nr)
> >  	if (spin_is_contended(pvmw->ptl))
> >  		return true;
> >
> > -	/* exclude special VMAs containing anon pages from COW */
> > -	if (vma->vm_flags & VM_SPECIAL)
> > +	/* exclude fixed and non-mm-managed VMAs containing anon pages from COW */
> > +	if (!vma_is_mm_managed(vma) || vma_is_fixed_mapping(vma))
> >  		return true;
>
> If you keep the droppable thing out there you can just use
>
> vma_is_mm_backed() here I think.

Yeah I think you're right, will update for v6!

>
> Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>

Thanks!

--
Cheers, Lorenzo