Re: [PATCH v2 12/20] mm, hugetlb: remove vma_has_reserves()

From: Joonsoo Kim
Date: Thu Aug 22 2013 - 05:21:42 EST


On Thu, Aug 22, 2013 at 02:14:38PM +0530, Aneesh Kumar K.V wrote:
> Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> writes:
>
> > vma_has_reserves() can be substituted by using return value of
> > vma_needs_reservation(). If chg returned by vma_needs_reservation()
> > is 0, it means that vma has reserves. Otherwise, it means that vma don't
> > have reserves and need a hugepage outside of reserve pool. This definition
> > is perfectly same as vma_has_reserves(), so remove vma_has_reserves().
> >
> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
>
> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>

Thanks.

> > @@ -580,8 +547,7 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
> > * have no page reserves. This check ensures that reservations are
> > * not "stolen". The child may still get SIGKILLed
> > */
> > - if (!vma_has_reserves(vma, chg) &&
> > - h->free_huge_pages - h->resv_huge_pages == 0)
> > + if (chg && h->free_huge_pages - h->resv_huge_pages == 0)
> > return NULL;
> >
> > /* If reserves cannot be used, ensure enough pages are in the pool */
> > @@ -600,7 +566,7 @@ retry_cpuset:
> > if (page) {
> > if (avoid_reserve)
> > break;
> > - if (!vma_has_reserves(vma, chg))
> > + if (chg)
> > break;
> >
> > SetPagePrivate(page);
>
> Can you add a comment above both the place to explain why checking chg
> is good enough ?

Yes, I can. But it will be changed to use_reserve in patch 13 and it
represent it's meaning perfectly. So commeting may be useless.

Thanks.

>
> -aneesh
>
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