On Tue, Aug 13, 2024 at 09:54:49PM -0600, Yu Zhao wrote:
> Support __GFP_COMP in alloc_contig_range(). When the flag is set, upon
> success the function returns a large folio prepared by
> prep_new_page(), rather than a range of order-0 pages prepared by
> split_free_pages() (which is renamed from split_map_pages()).
>
> alloc_contig_range() can be used to allocate folios larger than
> MAX_PAGE_ORDER, e.g., gigantic hugeTLB folios. So on the free path,
> free_one_page() needs to handle that by split_large_buddy().
>
> Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
> ---
> include/linux/gfp.h | 23 +++++++++
> mm/compaction.c | 41 ++--------------
> mm/page_alloc.c | 111 +++++++++++++++++++++++++++++++-------------
> 3 files changed, 108 insertions(+), 67 deletions(-)
>
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index f53f76e0b17e..59266df56aeb 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -446,4 +446,27 @@ extern struct page *alloc_contig_pages_noprof(unsigned long nr_pages, gfp_t gfp_
> #endif
> void free_contig_range(unsigned long pfn, unsigned long nr_pages);
>
> +#ifdef CONFIG_CONTIG_ALLOC
> +static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
> + int nid, nodemask_t *node)
> +{
> + struct page *page;
> +
> + if (WARN_ON(!order || !(gfp | __GFP_COMP)))
Andrew, could you patch up the line above? This is what it's supposed
to check:
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 59266df56aeb..03ba9563c6db 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -452,7 +452,7 @@ static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
{
struct page *page;
- if (WARN_ON(!order || !(gfp | __GFP_COMP)))
+ if (WARN_ON(!order || !(gfp & __GFP_COMP)))
return NULL;
page = alloc_contig_pages_noprof(1 << order, gfp, nid, node);
