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Date:   Thu, 20 Dec 2018 14:49:00 +0100
From:   Oscar Salvador <osalvador@suse.de>
To:     Wei Yang <richard.weiyang@gmail.com>
Cc:     Michal Hocko <mhocko@kernel.org>, 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
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On Thu, Dec 20, 2018 at 01:08:57PM +0000, Wei Yang wrote:
> This complicated the calculation. 
> 
> The original code is correct.
> 
> iter = round_up(iter + 1, 1<<compound_order(head)) - 1;

I think it would be correct if we know for sure that everthing
is pageblock aligned.
Because 2mb-hugepages fit in one pageblock, and 1gb-hugepages expands
512 pageblocks exactly.

But I think that it is better if we leave the assumption behind.
-- 
Oscar Salvador
SUSE L3