On Thu, Aug 22, 2024 at 2:21 AM Yu Liao <liaoyu15@xxxxxxxxxx> wrote:
>
> On 2024/8/14 11:54, 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)))
>
> It doesn't seem right, it should be !(gfp & __GFP_COMP).
Thanks. I've asked Andrew to patch this up (and another place in mm/cma.c).
