Re: [PATCH v2] mm, page_alloc: Fix has_unmovable_pages for HugePages

From: Michal Hocko
Date: Thu Dec 20 2018 - 08:06:11 EST


On Thu 20-12-18 13:49:28, Oscar Salvador wrote:
> On Thu, Dec 20, 2018 at 10:12:28AM +0100, Michal Hocko wrote:
> > > <--
> > > skip_pages = (1 << compound_order(head)) - (page - head);
> > > iter = skip_pages - 1;
> > > --
> > >
> > > which looks more simple IMHO.
> >
> > Agreed!
>
> Andrew, can you please apply the next diff chunk on top of the patch:
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 4812287e56a0..978576d93783 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8094,7 +8094,7 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> goto unmovable;
>
> skip_pages = (1 << compound_order(head)) - (page - head);
> - iter = round_up(iter + 1, skip_pages) - 1;
> + iter = skip_pages - 1;

You did want iter += skip_pages - 1 here right?

--
Michal Hocko
SUSE Labs