Re: [PATCH v14 084/138] mm/page_alloc: Add folio allocation functions

David Howells
2021-08-10T21:51:31Z

Matthew Wilcox (Oracle) <willy@infradead.org> wrote:

> +struct folio *folio_alloc(gfp_t gfp, unsigned order)
> +{
> + struct page *page = alloc_pages(gfp | __GFP_COMP, order);
> +
> + if (page && order > 1)
> + prep_transhuge_page(page);

Ummm... Shouldn't order==1 pages (two page folios) be prep'd also?

> + return (struct folio *)page;
> +}

Would it be better to just jump to alloc_pages() if order <= 1? E.g.:

struct folio *folio_alloc(gfp_t gfp, unsigned order)
{
struct page *page;

if (order <= 1)
return (struct folio *)alloc_pages(gfp | __GFP_COMP, order);

page = alloc_pages(gfp | __GFP_COMP, order);
if (page)
prep_transhuge_page(page);
return (struct folio *)page;
}

David