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Date:   Wed, 14 Sep 2022 00:34:16 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Doug Berger <opendmb@gmail.com>
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Subject: Re: [PATCH 03/21] mm/hugetlb: correct demote page offset logic
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References: <20220913195508.3511038-1-opendmb@gmail.com>
 <20220913195508.3511038-4-opendmb@gmail.com>
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On Tue, Sep 13, 2022 at 12:54:50PM -0700, Doug Berger wrote:
> With gigantic pages it may not be true that struct page structures
> are contiguous across the entire gigantic page. The mem_map_offset
> function is used here in place of direct pointer arithmetic to
> correct for this.

We're just eliminating mem_map_offset().  Please use nth_page()
instead.

>  	for (i = 0; i < pages_per_huge_page(h);
>  				i += pages_per_huge_page(target_hstate)) {
> +		subpage = mem_map_offset(page, i);
>  		if (hstate_is_gigantic(target_hstate))