Re: [PATCH v2 05/12] mm/hugetlb: unify hugetlb migration callback function

From: Michal Hocko
Date: Tue Jun 09 2020 - 09:44:05 EST


On Wed 27-05-20 15:44:56, Joonsoo Kim wrote:
[...]
> -/* page migration callback function */
> struct page *alloc_huge_page_nodemask(struct hstate *h,
> struct alloc_control *ac)
> {
> ac->gfp_mask |= htlb_alloc_mask(h);
> + if (ac->nid == NUMA_NO_NODE)
> + ac->gfp_mask &= ~__GFP_THISNODE;

Is this really needed? alloc_huge_page_node is currently only called
from numa migration code and the target node should be always defined.

>
> spin_lock(&hugetlb_lock);
> if (h->free_huge_pages - h->resv_huge_pages > 0) {
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 3b6b551..e705efd 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1073,9 +1073,10 @@ struct page *alloc_new_node_page(struct page *page, unsigned long node)
> struct alloc_control ac = {
> .nid = node,
> .nmask = NULL,
> + .gfp_mask = __GFP_THISNODE,
> };
>
> - return alloc_huge_page_node(h, &ac);
> + return alloc_huge_page_nodemask(h, &ac);
> } else if (PageTransHuge(page)) {
> struct page *thp;
>
> --
> 2.7.4
>

--
Michal Hocko
SUSE Labs