On Fri 05-10-18 13:04:43, Anshuman Khandual wrote:
> Does the following sound close enough to what you are looking for ?
I do not think so
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 9df1d59..070c419 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -504,6 +504,13 @@ static inline bool hugepage_migration_supported(struct hstate *h)
> return arch_hugetlb_migration_supported(h);
> }
>
> +static inline bool hugepage_movable_required(struct hstate *h)
> +{
> + if (hstate_is_gigantic(h))
> + return true;
> + return false;
> +}
> +
Apart from naming (hugepage_movable_supported?) the above doesn't do the
most essential thing to query whether the hugepage migration is
supported at all. Apart from that i would expect the logic to be revers.
We do not really support giga pages migration enough to support them in
movable zone.
> @@ -1652,6 +1655,9 @@ struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
> {
> gfp_t gfp_mask = htlb_alloc_mask(h);
>
> + if (hugepage_movable_required(h))
> + gfp_mask |= __GFP_MOVABLE;
> +
And besides that this really want to live in htlb_alloc_mask because
this is really an allocation policy. It would be unmap_and_move_huge_page
to call hugepage_migration_supported. The later is the one to allow for
an arch specific override.
Makes sense?
--
Michal Hocko
SUSE Labs
