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Date:   Thu, 20 Dec 2018 14:06:06 +0100
From:   Michal Hocko <mhocko@kernel.org>
To:     Oscar Salvador <osalvador@suse.de>
Cc:     Wei Yang <richard.weiyang@gmail.com>, akpm@linux-foundation.org,
        vbabka@suse.cz, pavel.tatashin@microsoft.com,
        rppt@linux.vnet.ibm.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] mm, page_alloc: Fix has_unmovable_pages for HugePages
Message-ID: <20181220130606.GG9104@dhcp22.suse.cz>
References: <20181217225113.17864-1-osalvador@suse.de>
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 <20181220091228.GB14234@dhcp22.suse.cz>
 <20181220124925.itwuuacgztpgsk7s@d104.suse.de>
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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