Re: [PATCH mm-unstable 3/8] mm/hugetlb: convert dequeue_hugetlb_page_node functions to folios

Matthew Wilcox
2023-01-03T21:00:08Z

On Tue, Jan 03, 2023 at 01:13:35PM -0600, Sidhartha Kumar wrote:
> +static struct folio *dequeue_hugetlb_folio_node_exact(struct hstate *h,
> + int nid)
> {
> struct page *page;
> + struct folio *folio;
> bool pin = !!(current->flags & PF_MEMALLOC_PIN);
>
> lockdep_assert_held(&hugetlb_lock);
> list_for_each_entry(page, &h->hugepage_freelists[nid], lru) {
> - if (pin && !is_longterm_pinnable_page(page))
> + folio = page_folio(page);

I'd argue that you can pull folios directly off the hugepage_freelists.
Since they're attached through the 'lru', you know they're not tail
pages, because lru.prev aliases with compound_head.

The rest looks good.